Whole-Food Plant-Based Diet

Diet Reference Archive: eating pattern

Whole-Food Plant-Based Diet

An eating pattern built mostly or entirely on whole and minimally processed plant foods: vegetables, fruits, whole grains, legumes, nuts and seeds. It is defined by the quality of the food more than by one rule about animal foods, and its promoters present it as a way to prevent chronic disease and, in clinical programs, to treat it.

Family: Plant-based and plant-forward diets Promoted by: nutrition researcher T. Colin Campbell, physician authors, and the American College of Lifestyle Medicine First appeared: the late 1970s, by the account of the researcher who coined the term GRADE: Low for the association of higher healthful plant-based diet index scores with less type 2 diabetes, in adults in prospective cohort studies, highest against lowest score groups, over follow-up of 2 to more than 20 years; this page's own judgment

ON THIS PAGE

1. In brief
2. Overview
3. In practice
4. For the coach
5. The evidence (opens on request)
6. Mechanisms (opens on request)
7. Risks, contraindications and myths (opens on request)
8. Key terms
9. Review questions
10. References
11. Evidence rating and review record

The summary and sections 1 to 3 are the short version and are open when the page loads. Sections 4 to 6 hold the research detail, the biology, and the cautions. Each of those opens when you select its heading, and you can read the page without opening them. Back to the Diet Reference Archive index.

In brief

What is it? A way of eating built on plant foods in a form close to how they grow: vegetables, fruits, whole grains, beans and lentils, nuts and seeds, with few refined or packaged foods. "Whole" refers to how processed the food is, and "plant-based" to how much of the diet comes from plants. The sources that define it do not agree on one point that matters to clients: some exclude every animal food and all added oil, while others, including the American College of Lifestyle Medicine's current position, ask people to keep red and processed meats to a minimum rather than to give up all animal foods.

Does it work? No trial found for this page has measured whether eating this way changes heart attacks, strokes, cancer or length of life. Short randomized trials of whole-food plant-based programs, lasting up to 6 months and usually including classes, cooking lessons or other lifestyle changes, found lower HbA1c, a blood test of average blood sugar, and lower body weight than usual care in adults with type 2 diabetes or heart risk factors. A 4-week feeding trial found lower LDL cholesterol. In large studies that follow people for years, those whose eating scores highest for healthful plant foods have less type 2 diabetes, heart disease and death, and those whose plant foods are mostly refined grains, potatoes, sweets and sugary drinks have more. Those are associations, and the certainty is low.

Is it safe? For most adults the foods are ordinary foods. The 2 cautions that matter most are these. A version with no animal foods needs a reliable source of vitamin B12, and its other nutrients need planning. And for people taking medicine for diabetes or blood pressure, a large change in eating can lower blood sugar or blood pressure faster than the medicine dose is adjusted.

Who should not do it without talking to a doctor or dietitian first? Anyone taking insulin, a sulfonylurea, blood pressure medicine or warfarin. Anyone with kidney disease. Anyone who is pregnant, trying to become pregnant or breastfeeding. Children and teenagers. Older adults with a small appetite or weight they are losing without meaning to. And anyone with a history of disordered eating.

Related pages: Mediterranean Diet, DASH Diet, and the Vegan Diet, Vegetarian Diet, Flexitarian Diet, Pescatarian Diet and Whole Food Plant-Based Plate pages. Full list on the archive index.

1. Overview

What you eat

The center of the plate is plants eaten whole or close to whole: vegetables of every kind, including leafy greens, starchy vegetables such as sweet potatoes and squash, and mushrooms; fruits; whole grains such as oats, brown rice, barley, whole wheat and corn; legumes, meaning beans, lentils, peas and soy foods such as tofu and tempeh; and nuts and seeds. Herbs and spices carry the flavor, and water is the usual drink. Most versions describe food groups rather than portions.

"Minimally processed" means that a food has been washed, cut, cooked, frozen, canned or ground but still contains what the plant contained. Rolled oats, frozen vegetables, canned beans and whole grain bread fit. White bread, sweetened cereal, chips, pastries, sugary drinks and many products sold as "plant-based" meat or cheese substitutes do not, even though they come from plants.

What you avoid or limit

Every version limits refined grains, added sugars, sweets and highly processed foods. The versions differ on 2 things: animal foods and added oils.

In the strict versions, all animal foods are left out. A cardiologist's definition says a plant-based diet "excludes all animal products, including red meat, poultry, fish, eggs, and dairy products" (Ostfeld, 2017). Researchers at Tufts University who modeled the diet described whole-food plant-based and vegan diets as both excluding all animal products, with the whole-food version placing "a greater emphasis on minimizing or excluding all processed foods made with refined grains and added sugar, refined fats and oils, and salt" (Karlsen et al., 2019). The strictest clinical versions also remove added oils. The New Zealand BROAD trial asked participants to avoid refined oils and all animal products and discouraged nuts and avocados (Wright et al., 2017), and several U.S. trials removed all animal products and all added oils and solid fats (T. M. Campbell et al., 2023, 2024).

Other definitions are looser. An article for physicians by Kaiser Permanente clinicians defined a plant-based diet as one that "encourages whole, plant-based foods and discourages meats, dairy products, and eggs as well as all refined and processed foods" (Tuso et al., 2013), which discourages animal foods without forbidding them. The American College of Lifestyle Medicine's 2026 position says the core diet should be "centered on a wide variety of whole and minimally processed plant foods" and that it should "minimize red and processed meats, foods high in saturated fat, and ultra-processed foods" (American College of Lifestyle Medicine, n.d.). An article on the College's own website, by contrast, describes a whole-food plant-based diet as one that "excludes animal foods" (American College of Lifestyle Medicine, 2023). So a client's version may forbid all animal foods, or allow some.

Research uses the term just as loosely. A review of 44 intervention studies of "plant-based" diets found that half excluded all animal products, about 20 percent allowed meat and fish, and 34 percent allowed dairy; 13 of the 44 used the prefix "whole-food." Its author called for a consensus definition (Storz, 2022). In one trial labeled whole-food plant-based, about 18 percent of the energy in the provided diet came from animal foods (Lessard-Lord et al., 2026). Each study described on this page therefore says what its version allowed.

Where it came from

T. Colin Campbell, a nutrition researcher, writes that in the late 1970s, as the only nutrition researcher on a National Cancer Institute review committee, he chose the words "plant-based" to describe evidence on plant foods and cancer, partly "to distinguish it from the animal rights motivation of vegetarianism." Shortly afterward, while testifying in Federal Trade Commission hearings on supplement health claims, he added "whole," giving "whole food, plant-based" (T. C. Campbell, 2024). That is his own account, in a textbook chapter he wrote.

The pattern spread through books, physician-led programs and documentaries. Physicians such as Caldwell Esselstyn at the Cleveland Clinic and Dean Ornish built programs for heart disease around very low fat diets without added oil, which the American Heart Association groups with the Pritikin and McDougall programs as very low fat patterns (Gardner et al., 2023). Esselstyn reports starting a small study of 24 patients with severe coronary disease in 1985 (Esselstyn, 2017). Participants in the BROAD trial watched the documentary Forks Over Knives as part of the program (Wright et al., 2017).

In 2018 the American College of Lifestyle Medicine, a professional society of clinicians, issued a position recommending "an eating plan based predominantly on a variety of minimally processed vegetables, fruits, whole grains, legumes, nuts and seeds" (American College of Lifestyle Medicine, 2018), and in February 2026 it issued an updated 4-part statement (American College of Lifestyle Medicine, n.d.; Karlsen, 2026).

The College also publishes a patient handout titled "A Whole Food, Plant-Based Plate." That handout has its own page in this archive, the Whole Food Plant-Based Plate page, which covers it as a teaching tool; this page covers the eating pattern itself.

What it claims to do

The strongest claims come from its promoters and are stated here as claims. The College's position is that this way of eating is for "the treatment, reversal, and prevention of lifestyle-related chronic diseases" (American College of Lifestyle Medicine, n.d.). Campbell writes that "the same dietary protocol can reverse or treat most chronic degenerative diseases" (T. C. Campbell, 2024). Esselstyn reports that in a study of 198 patients with significant coronary disease, "99.4% of the participants who adhered" to the diet avoided a major cardiac event, a figure that excludes the 21 who did not adhere (Esselstyn, 2017); it comes from an uncontrolled case series, not a trial.

Clients also meet milder claims: that the diet lowers cholesterol and blood sugar, helps with weight, reduces medicines, and is better for the planet. Section 4 takes the evidence for each kind of claim in turn, and section 6 takes several as myths.

What it gets right

The foods at its center are the foods that current heart-health guidance emphasizes. The American Heart Association's 2026 dietary guidance, which this program uses for nutrition claims, includes plenty of vegetables and fruits, whole grains, a shift from meat to plant sources of protein such as legumes and nuts, and minimally processed foods in place of ultraprocessed ones among the features of a heart-healthy pattern. It concludes that "dietary patterns higher in plant sources of protein and lower in animal sources of protein are associated with better cardiovascular health" (Lichtenstein et al., 2026).

Its insistence on "whole" also matters. Research that separates healthful from unhealthful plant foods finds that a diet can be high in plant foods and still go with more heart disease when those foods are refined grains, sweets, sugary drinks and potatoes (Satija et al., 2017). A coach can honor a client's interest in eating more plants without endorsing the whole package or its strongest claims.

How clients describe it, and what it gets confused with

Clients say "I eat whole-food plant-based," "I'm WFPB," "I went plant-based," "plant-forward," "plant-predominant," "no oil," "I'm doing Forks Over Knives," or "my doctor put me on a plant-based diet." Some mean no animal foods at all; some mean mostly plants with some fish, eggs or dairy; some mean they buy products labeled plant-based. Asking what the words mean to this client comes first.

It is most often confused with its neighbors in this archive's plant-based family, which are defined by which animal foods they leave out rather than by how processed the food is. The Vegan Diet page covers leaving out all animal foods, whether or not the remaining foods are minimally processed. The Vegetarian Diet page covers patterns without meat, poultry or fish that may include eggs or dairy. The Flexitarian Diet page covers patterns that reduce meat while still allowing it. The Pescatarian Diet page covers eating fish or seafood while leaving out meat and poultry.

It is also confused with the Mediterranean Diet, which is plant-forward but includes fish, olive oil and some dairy, and with oil-free, very low fat programs such as the Ornish and Pritikin programs. The College's handout has its own page, the Whole Food Plant-Based Plate.

2. In practice

A typical day of eating

A day in a strict version, with no animal foods and no added oil, might look like this. Breakfast is oatmeal cooked in a fortified soy drink, with berries and a spoonful of ground flaxseed. Lunch is a large bowl of lentil and vegetable soup with whole grain bread and a salad of leafy greens, tomatoes and chickpeas, dressed with vinegar and mustard. An afternoon snack is an apple with a small handful of walnuts or a spoonful of peanut butter. Dinner is black beans and roasted sweet potato over brown rice, with salsa, corn and steamed broccoli; vegetables are roasted on parchment or cooked in water or broth rather than oil. Water and unsweetened tea are the drinks, and a vitamin B12 supplement or B12-fortified foods are part of the plan.

A plant-predominant day, as the College's current position allows, could look much the same with a few changes: plain yogurt at breakfast, a little olive or canola oil in the cooking, and fish or eggs once or twice a week. Both days are built on the same whole plant foods. Neither includes packaged plant-based burgers, vegan cheese, pastries or sweetened drinks, which are made from plants but are not whole foods.

Cost, products, and who profits

The core foods are ordinary staples such as dry or canned beans, lentils, oats, brown rice, potatoes, frozen vegetables and fruit. The closest direct measurement found for this page comes from a small U.S. study of adults with insulin-treated type 2 diabetes who ate their usual diet, then a DASH diet, then a whole-food plant-based diet, with meals provided. Food costs as eaten were $15.72 a day at baseline, $12.74 on DASH and $9.78 on the whole-food plant-based diet; adjusted to 1,800 calories a day they were $15.69, $14.92 and $11.96. Only 12 of the 15 people enrolled completed all phases, the order was not randomized, and this page read only the study's abstract (E. K. Campbell, Taillie, et al., 2024).

A global modeling study priced diets built on legumes and whole grains in place of animal foods and found that, in high-income and upper-middle-income countries, vegetarian and vegan versions of that kind cost 22 to 34 percent less than current diets on average; those are modeled estimates from international food prices, not what households paid (Springmann et al., 2021). The real cost is often time: cooking beans and whole grains takes planning, and the BROAD program included chef-guided cooking lessons (Wright et al., 2017).

Money attaches to the name in several places. Plant-based meat and dairy substitutes are sold under the same label, and the American Heart Association cautions that many plant-based meat alternatives "are ultraprocessed and come with added sugars, sodium, stabilizers, and preservatives" (Lichtenstein et al., 2026); they are not part of a whole-food diet even when labeled plant-based.

Books, programs and professional certification also carry the name. The College reports that almost 7,000 clinicians and health professionals in the U.S. and Canada have earned its lifestyle medicine certification since 2017 (Karlsen, 2026). Authors of several trials described in section 4 disclosed royalties from books about plant-based eating, or formed a plant-based lifestyle company after their trial ended (T. M. Campbell et al., 2023; Hanick et al., 2025; Wright et al., 2017), and some of the cohort research on plant-based diet scores was conducted by authors who disclosed research support from walnut and blueberry industry groups (Satija et al., 2017). None of these ties makes a finding wrong. They are worth knowing when a client brings a claim.

Environmental footprint

The footprint depends on which plant foods a person chooses, and on what they replace. The most direct evidence found for this page comes from 65,625 U.S. women in the Nurses' Health Study II, whose usual diets were scored on the plant-based diet indices described in section 4 and matched to published estimates of each food's greenhouse gas emissions, cropland, nitrogen fertilizer and irrigation water, measured to the farm gate. Standardized to 2,000 calories a day, women in the highest fifth of the healthful plant-based index had diets estimated at 2.7 kilograms of carbon dioxide equivalents a day, against 3.5 in the lowest fifth, with lower cropland, fertilizer and water needs. Women whose plant foods were mostly the less healthy kind, the unhealthful index, showed no clear difference in emissions, 3.1 against 3.2, and needed more cropland and fertilizer (Musicus et al., 2022).

Red and processed meat contributed 31 percent of the emissions from these women's diets, more than any other food group (Musicus et al., 2022). The figures are modeled from what people reported eating, not measured. The American Heart Association notes that the patterns that align best with its dietary guidance "also have lower environmental impact and are more supportive of planetary health because of reduced meat intake" (Gardner et al., 2023).

Cultural fit

Because the diet is built from food groups rather than dishes, many food traditions already contain meals that fit it: rice and beans, lentil dal with flatbread, bean and vegetable stews, tofu stir-fries, corn tortillas with beans, and grain and vegetable soups. It is harder where meat, fish, eggs or dairy carry much of a culture's meaning, its hospitality or its protein, and where family meals are shared. Campbell argues that the flavors of many cuisines can be kept while the foods change (T. C. Campbell, 2024); how that works for a given family is a practical question, not a matter of evidence.

The research base itself is not diverse. The U.S. cohorts that built the plant-based diet indices were made up of health professionals who were 95 to 99 percent White (Satija et al., 2016), and in an African American cohort in Mississippi the indices were not associated with cardiovascular disease or death (Weston et al., 2022). A review of 56 studies of why people follow plant-based diets found that almost three-fifths of the samples were more than 75 percent women (Miki et al., 2020).

What makes people stop

The trials give some numbers on staying with it. In the BROAD trial, 25 of 33 people in the program, 76 percent, completed the 6-month study (Wright et al., 2017). In a 24-week trial in the Marshall Islands, 20 percent of participants were lost to follow-up, similar in both groups, and the program provided prepared meals and many hours of classes each week at the start, tapering off, with no support at all in its last 12 weeks (Hanick et al., 2025). In an 8-week trial in women with metastatic breast cancer that provided 3 meals a day, 18 of the 19 participants with complete records met the study's adherence target (E. K. Campbell, Campbell, et al., 2024).

In a 1-year trial in children and their parents described in section 3, only a third of the families came to the final visit (Macknin et al., 2021). In a 15-day pilot in adults with kidney disease, 2 of the people assigned to the program withdrew before it began because the diet seemed too restrictive, and 11 of the 12 who gave feedback afterward expected barriers, most often that the diet was too restrictive and made eating away from home hard (Liebman et al., 2025).

The American Heart Association names the main problem for the strictest versions: for vegan patterns, "a key challenge" is their "restrictive nature, making it infeasible and an impediment for long-term adherence for most patients," and for very low fat patterns, "few people adhere to strict macronutrient targets" (Gardner et al., 2023). Beyond that, what follows is observation rather than measured data: eating out, family meals in which others eat differently, cooking time, and the feeling that one meal with cheese or oil means failure.

What happens when you stop

No study found for this page followed people after they deliberately stopped. A few trials show what happened as support faded. In the Marshall Islands trial, the HbA1c difference between groups was 14 mmol/mol at 12 weeks, at the end of the supported phase, and 8 mmol/mol at 24 weeks, after 12 weeks without support (Hanick et al., 2025). In the BROAD trial, the program group's average body mass index was 4.2 points below its starting value at 12 months, close to the 4.4 points at 6 months; the control group was offered the program after 6 months, so this is one group over time, not a comparison (Wright et al., 2017).

In a Dutch lifestyle program for rheumatoid arthritis that included a whole-food plant-based diet, followed for a year after the 16-week program without a control group, the improvement in disease activity was still present, while body weight had returned to near its starting value (Wagenaar et al., 2024).

Common variations

The oil-free, very low fat versions: the American Heart Association groups the Ornish, Esselstyn, Pritikin and McDougall programs and the Physicians Committee for Responsible Medicine's diet as very low fat patterns that "avoid" oils, nuts and seeds, meats, poultry, fish, dairy and eggs (Gardner et al., 2023).

The fully plant whole-food version, with all animal foods excluded but nuts, seeds and sometimes oils allowed, as in the definition by Karlsen and colleagues (2019). The plant-predominant version, built on the same whole plant foods with small amounts of animal foods, as in the College's 2026 position and in the Marshall Islands trial, which allowed small amounts after its first 2 weeks (Hanick et al., 2025). And versions built mostly from packaged vegan products, which share the label "plant-based" but not the "whole food" part; the Vegan Diet page covers vegan eating of every kind. Raw food diets, limited to uncooked foods, are a different pattern again.

3. For the coach

SCOPE OF PRACTICE

A health and wellness coach does not prescribe, adjust, endorse or discourage a whole-food plant-based diet, and does not diagnose or treat. The coach helps the client understand what they have chosen, notice how it is going, and decide what to do next. When the College or a program speaks of treating or reversing disease, it is describing clinical work done by licensed clinicians; the College's own position says such care is "best achieved with an interprofessional healthcare team all working within their scope of practice," ideally including registered dietitian nutritionists (American College of Lifestyle Medicine, n.d.).

A physician or other prescriber needs to be involved before a substantial change in eating by a client who takes insulin, a sulfonylurea, blood pressure medicine or warfarin. A registered dietitian is the right professional for planning a version with no animal foods, and for pregnancy, breastfeeding, children, kidney disease, older adults with a small appetite, and anyone with a history of disordered eating.

Who does what

The physician

Decides whether a large change in eating is medically safe for this person and adjusts any medicine it affects. In the trials described in section 4, physicians lowered insulin and other diabetes medicines as blood sugar fell, and in one trial general practitioners made all prescribing decisions (Hanick et al., 2025; Wright et al., 2017). Orders and reads the labs that matter for this diet: HbA1c, the lipid panel, kidney function, and vitamin B12 status where a version leaves out animal foods.

The registered dietitian

Designs and monitors the individual plan: checks protein, vitamin B12, vitamin D, calcium, iodine, iron, zinc and omega-3 fats against the person's needs, chooses fortified foods or supplements where they are needed, and adapts the plan to a diagnosed condition, a pregnancy, a child's growth, kidney disease, athletic training or a food tradition. The American Heart Association encourages referral to a registered dietitian for people interested in vegan patterns (Gardner et al., 2023).

The health and wellness coach

Helps the client say what they want from this way of eating and why now, and what "whole-food plant-based" means in their own kitchen. Explores how it fits their budget, cooking time, family meals, culture and social life, and helps them build the habits that make their chosen approach workable, one meal or one food at a time if that is what they choose. With the client's permission, can share general guidance from recognized authorities, such as the American Heart Association's guidance on plant sources of protein, and explore how the client wants to use it. Notices whether eating is widening or narrowing, and holds the referral line.

What a client bringing this diet needs

Clients come to this diet for different reasons: a new diagnosis of type 2 diabetes or high cholesterol, a clinician's advice, a documentary, a family member's experience, concern for animals or the environment, or wanting to feel better. In a review of 56 studies of plant-based eaters, health was the motivation most often studied, followed by taste, then the environment and animal welfare about equally, and weight loss (Miki et al., 2020).

What clients usually need is help with the distance between a strict definition and a real week: what to cook on a busy evening, how to eat with a family that is not changing, whether one version is "allowed" to include fish or oil, and what to do on the days it does not happen. Questions about nutrients, supplements or medicine can be written down for the dietitian or prescriber. The coaching conversation offers what a book or documentary cannot: clarity about the client's own reasons, a realistic look at how the plan fits their life, and a plan they own.

What to ask

• When you say whole-food plant-based, what does a usual day of eating look like for you?
• What drew you to this way of eating, and what are you hoping will be different?
• Which meals you already eat are closest to what you have in mind?
• Who on your health care team knows about this change, and what did they say about your medicines?

Referral red flags

A client who takes insulin or a sulfonylurea and is starting, or has started, a large change toward this diet goes to the prescriber before going further, because blood sugar can fall quickly; in one trial a participant had low blood sugar in the first week and his general practitioner reduced and then stopped his insulin (Wright et al., 2017). A possible low blood sugar episode calls for immediate action under the client's own diabetes plan. Severe symptoms, or an episode the person cannot manage, call for emergency help; afterward the client tells the prescriber about the episode.

A client on blood pressure medicine who describes dizziness or lightheadedness, especially on standing, is describing something for the prescriber; in one trial, 3 participants on the diet, 2 of them taking blood pressure medicine, had symptoms of low blood pressure and were referred to their own clinicians for medicine adjustment (T. M. Campbell et al., 2024). A client on warfarin who plans to eat a lot more leafy green vegetables goes to the prescriber first, for the reason given in section 6. Pregnancy, breastfeeding, a parent planning a child's diet, kidney disease, and an older adult with a small appetite go to the clinician and a dietitian.

Tiredness that does not lift, or other new symptoms, in a client who has eaten no animal foods for years without a reliable source of vitamin B12, is for the clinician to evaluate. Vitamin B12 deficiency can cause fatigue and neurological changes, and its symptoms can take several years to appear (National Institutes of Health, Office of Dietary Supplements, 2025). The coach notices and encourages the client to tell their clinician; working out the cause is the clinician's job. Weight a client loses without meaning to is a reason to involve a clinician, never a sign the diet worked.

A client whose food rules keep getting stricter is worth asking about it. A coach notices and asks what a restriction is for, whether it causes distress, narrows eating or disrupts daily life, while recognizing ordinary explanations, such as a plan a client's physician prescribed or a recipe the client is still learning. A real concern follows their own referral process, or is raised with the client's existing clinician. None of these referrals ends the coaching relationship.

Special populations

Pregnancy and breastfeeding

The searches for this page did not identify a randomized trial of a whole-food plant-based diet in pregnancy. In a U.S. cohort of 7,981 people in their first pregnancy, those whose eating around conception scored in the highest third of the healthful plant-based index had fewer hypertensive disorders of pregnancy (adjusted risk ratio 0.77, 95 percent confidence interval 0.64 to 0.92) and less gestational diabetes (0.55, 0.39 to 0.76) than those in the lowest third, associations that weakened when prepregnancy body mass index, chronic high blood pressure and diabetes before pregnancy were taken into account (Jancsura et al., 2026). A smaller Iranian cohort of 635 pregnant women found a similar association with gestational diabetes (Bazshahi et al., 2024). The Academy of Nutrition and Dietetics' position on vegetarian and vegan patterns covers only adults who are not pregnant or breastfeeding (Raj et al., 2026). Guidance for health professionals recommends a 150 microgram daily iodine supplement for all pregnant and breastfeeding women and reliable daily sources of vitamin B12 for those who are vegetarian (Craig et al., 2021). Eating in pregnancy and while breastfeeding is planned with the obstetric team and a dietitian, and the Vegan Diet page covers pregnancy without animal foods.

Children and adolescents

In a randomized trial in Ohio, 96 pairs of a child aged 9 to 18 and a parent were assigned to a whole-food plant-based diet with no added fat, with vitamin B12 and vitamin D supplements, or to an American Heart Association or a Mediterranean diet, with group classes and support calls over a year. The children had a body mass index above the 95th percentile for their age and sex and had raised cholesterol on a test in the previous 2 years.

The trial did not demonstrate an advantage of any of the 3 diets in the children, only a third of the pairs completed the 52-week visit, and children on the plant-based diet reported less protein and vitamin D from food than those on the other diets. It was funded by a foundation that supports plant-based diets, and it was not designed to show whether the diet supports normal growth (Macknin et al., 2021).

One cross-sectional study of 287 Canadian children aged 1.5 to 6 years found no association between plant-based diet index scores and body composition; this page read its abstract (Leung et al., 2025). Guidance for health professionals states that plant milks and other milks "should not be used to replace breast milk or formula during the first year" and that protein needs of vegan children may be somewhat higher than standard recommendations (Craig et al., 2021). A child's eating plan belongs to the family, the child's clinician and a dietitian; the Vegan Diet page covers children raised without animal foods.

Older adults

In a German randomized trial in 271 adults aged 60 and older with mild cognitive impairment, 6 months of online group counseling on a whole-food plant-based diet that advised avoiding animal foods was compared with counseling on a healthy omnivorous diet based on German national guidelines, within a trial that also tested computer-based cognitive training. Its report on eating habits, from 261 people's food questionnaires, found that most people in both groups kept eating meat, with only small differences between the groups; 12 months after the start, about 92 percent of the plant-based group still did. That report does not include the trial's main results on thinking and memory, so it does not show a benefit for either (Hanslian et al., 2025).

In 105,015 U.S. health professionals followed for up to 30 years, those in the highest fifth of the healthful plant-based index were more likely to reach age 70 free of 11 chronic diseases and with intact thinking, physical function and mental health (odds ratio 1.45, 1.35 to 1.57), although this was the weakest of the 8 healthy patterns the study compared (Tessier et al., 2025). Older adults are a group at higher risk of vitamin B12 deficiency (National Institutes of Health, Office of Dietary Supplements, 2025), and guidance suggests that older vegetarians eat higher protein foods such as soy foods, legumes and nuts 2 to 3 times a day and rely on fortified foods and supplements for vitamin B12 (Craig et al., 2021). For an older adult with a small appetite or low body weight, a dietitian and physician belong in the plan.

Athletes and people with high activity

The searches for this page did not identify a trial of a whole-food plant-based diet in athletes. In a randomized crossover study of 36 recreational runners and strength trainers who completed it, 4 weeks of swapping meat for plant protein, which is not a whole-food plant-based diet, did not demonstrate a difference in running or composite strength (minus 4.0 percent, from minus 8.5 to plus 0.5), with tests the participants ran themselves (Raygoza et al., 2026). A meta-analysis of 8 small trials with 188 participants found no clear difference in strength between plant-based and omnivorous diets (López-Moreno et al., 2025); 3 of its trials, with the same sample size and design, may describe one study. Energy and protein for training are planned with a sports dietitian.

People taking medication for diabetes, blood pressure, or blood thinning

This is the group where the prescriber most clearly comes first. In a 24-week trial of a whole-food plant-based program in adults with type 2 diabetes, 63 percent of participants taking diabetes medicine reduced their dose, against 24 percent with standard care, under a protocol that told participants on insulin when to reduce it (Hanick et al., 2025). Blood pressure medicines may also need review, and warfarin depends on a steady intake of vitamin K (American Society of Health-System Pharmacists, 2026). The standing rule holds: for a substantial change in eating by a client on these medicines, the client keeps the prescriber informed before the change.

People with kidney disease

In a U.S. cohort of 14,686 middle-aged adults followed for a median of 24 years, those in the highest fifth of the healthful plant-based index developed chronic kidney disease less often (hazard ratio 0.86, 0.78 to 0.96); this page read the study's abstract (Kim, Caulfield, Garcia-Larsen, Steffen, Grams, et al., 2019). That is a study of who developed kidney disease, not a test of the diet in people who have it. For a person who already has kidney disease, individual needs depend on kidney disease stage, laboratory results and dialysis, and the kidney care team belongs in the plan. Plant foods are not a hazard for everyone with kidney disease, and the decision is not the coach's.

The one trial found for this page is small. In a randomized pilot in Rochester, New York, 43 adults with stage 3 or 4 chronic kidney disease and treated high blood pressure, without diabetes or substantial protein in the urine, were assigned to a 15-day online whole-food plant-based education program, which advised leaving out all animal foods and added oils, or to usual care. Forty participants were included in the analysis. The change in systolic blood pressure favored the program by 10.7 mm Hg, but the difference was not statistically clear. Changes in potassium did not differ clearly between the groups. Three people in each group had mild high potassium that resolved on its own.

In the program group, 3 people had symptoms of low blood pressure, which resolved after advice on salt or fluids or after a diuretic was stopped, and 1 had a rise in creatinine counted as acute kidney injury, in a person whose creatinine had varied before the study. Three people assigned to the program withdrew before starting and were replaced. The trial's size, length and selection mean it cannot establish safety or benefit for people with kidney disease in general (Liebman et al., 2025).

People with a history of disordered eating

The searches for this page found no study of whole-food plant-based eating in people with a history of an eating disorder. A meta-analysis of 26 cross-sectional studies with 23,783 adults found higher orthorexia symptom scores, a preoccupation with eating only foods seen as healthy and pure, in vegetarians and vegans than in omnivores; 84.6 percent of the studies were rated poor in quality, and such studies cannot show whether the diet or the symptoms came first (Díaz-Goñi et al., 2026). Strict versions come with firm rules about oil, animal foods and processed foods, and any set of food rules can become rigid for some people. A concern goes through the coach's own referral process, or to the client's clinician under an existing care plan.

Client misconceptions

Three misconceptions come up often: that anything plant-based is healthy; that the diet has been proven to reverse heart disease and diabetes; and that a whole-food diet needs no supplements. Section 6 sets out where each came from and what the evidence shows. The practical point for the coach is that a question about what a client's own lab result means, or whether a medicine can be stopped, goes to the prescriber.

🤝 COACHING CONNECTION

Linda is 58 and has type 2 diabetes. After watching a documentary, she says she is going "fully plant-based, no oil, starting Monday," and her freezer is already full of vegan burgers and dairy-free ice cream. The coach asks what she is hoping will change. Linda says she wants more energy and to need fewer pills. The coach asks what her doctor knows about the plan. She says nothing yet; she takes insulin at night and is not sure how the change might affect it. The coach asks how she would like to handle that. Linda decides to call her clinic before Monday. Then she says she does not like beans much but loves her mother's lentil soup, and wonders whether that could be a start. Nothing was recommended, and the diet was never evaluated.

4. The evidence

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The evidence comes in 2 kinds that answer different questions. Randomized trials of programs built around a whole-food plant-based diet are few, small and short, usually 6 months or less, and most bundled the diet with classes, cooking lessons, provided meals, exercise or stress management. They show lower HbA1c and body weight than usual care, and lower LDL cholesterol in a 4-week feeding trial and a short trial in women with breast cancer, though not in the 2 larger program trials; none measured heart attacks, strokes, cancer or deaths.

The long-term evidence comes from cohort studies that score ordinary diets on plant-based diet indices. Higher scores on the healthful index go with less type 2 diabetes, heart disease and death, and higher scores on the unhealthful index with more. Those are associations in people who mostly still ate animal foods, not tests of following the diet. Trials of vegan diets as such, defined by leaving out animal foods rather than by food quality, are on the Vegan Diet page.

Evidence from randomized controlled trials

A trial assigns people to the diet by chance and compares them with people assigned to something else, which is the strongest way to test whether the diet itself causes a result. The trials below tested diets their authors called whole-food plant-based. Participants knew what they were eating, so none could be blinded, and because most also changed other things, such as exercise, classes or provided meals, they test a program rather than the diet alone.

Cardiometabolic outcomes

The largest trial in type 2 diabetes found for this page randomized 169 adults with type 2 diabetes in the Republic of the Marshall Islands to standard medical care or to an intensive program: a whole-food plant-based diet with no animal foods for 2 weeks and small amounts allowed afterward, 30 to 60 minutes of exercise a day, prepared meals and many hours of classes a week at the start, tapering to nothing after 12 weeks. Of those randomized, 31 withdrew before baseline testing; 70 and 66 people were analyzed (Hanick et al., 2025).

HbA1c fell 14 mmol/mol (1.3 percentage points) more in the program group at 12 weeks and 8 mmol/mol (0.7 percentage points) more at 24 weeks, with a 95 percent confidence interval of 1 to 14 mmol/mol at 24 weeks. Of the participants taking diabetes medicine, 63 percent of the program group reduced their dose, against 24 percent with standard care. No difference in LDL cholesterol was detected, and systolic blood pressure was lower only in the first 6 weeks. The program combined diet with exercise, no records of what people ate were collected, and the organization that developed and delivered the program also helped fund the trial (Hanick et al., 2025).

In the BROAD trial in New Zealand, 65 adults with overweight or obesity and type 2 diabetes, heart disease, high blood pressure or high cholesterol were randomized to usual care or to usual care plus a 12-week program of twice-weekly evening classes on a low-fat whole-food plant-based diet with no animal foods and no refined oils, without calorie limits and with vitamin B12 supplements. At 6 months, 49 of the 65 remained. HbA1c was 5 mmol/mol lower than with usual care; the difference in total cholesterol, 0.45 mmol/L, was not statistically clear, and no difference in LDL cholesterol or blood pressure was detected (Wright et al., 2017).

A fully controlled feeding trial in Québec tested the diet's effect on LDL cholesterol in 51 adults with heterozygous familial hypercholesterolemia, an inherited cause of very high cholesterol, who stopped their cholesterol medicine for the study. Each person ate a provided whole-food plant-based diet and a typical North American diet for 4 weeks each, in random order, with calories set to keep weight steady. LDL cholesterol was 1.28 mmol/L lower on the plant-based diet, from 1.02 to 1.55 lower, a 17.9 percent reduction. This version was not vegan: about 18 percent of its energy came from animal foods, red meat was eaten once a week, and canola oil was used in cooking (Lessard-Lord et al., 2026).

Two smaller studies tested details of the strict versions. In a randomized crossover trial in 60 adults at raised cardiovascular risk, of whom 40 completed it, adding 4 tablespoons of extra virgin olive oil a day to a whole-food plant-based vegan diet, compared with almost no added oil, did not demonstrate a difference in LDL cholesterol overall, 1.6 mg/dL higher with olive oil and not statistically clear, although the result depended on which diet came first (Krenek et al., 2024). In a nonrandomized study in which 15 adults with insulin-treated type 2 diabetes ate provided meals for a week each of DASH, whole-food plant-based and DASH again, 12 completed all phases; insulin needs were 39 percent below baseline at the end of the whole-food plant-based week, but with no washout between weeks the authors state the effects of the 2 diets "cannot be isolated" (T. M. Campbell et al., 2023).

Cancer

No trial found for this page measured whether the diet prevents cancer. In a randomized trial in 32 women with metastatic breast cancer on stable treatment, 21 were assigned to 8 weeks of a provided whole-food plant-based diet with no animal foods or added oils and 11 to their usual diet, and 30 completed it. Body weight, total cholesterol and LDL cholesterol fell more on the diet, but no difference in blood markers of cancer activity was detected (T. M. Campbell et al., 2024). A later analysis of inflammatory markers from the same trial, which its authors describe as post hoc and "hypothesis-generating," found few clear differences between groups, mainly in leptin, a hormone made by fat tissue (Rieth et al., 2025). These short studies do not establish an effect on cancer progression or survival.

Body weight, as measured

This archive reports body weight as something a study measured, in that study's own numbers, and not as a goal or as a measure of whether a way of eating worked; see the standing rule in the review record at the foot of this page. The one exception is weight a person loses without meaning to, which can signal a health problem and is a reason to involve a clinician, never a sign that a diet worked.

In the Marshall Islands trial, weight at 24 weeks was 2.7 kilograms lower in the program group than with standard care, from 1.8 to 3.6 (Hanick et al., 2025). In BROAD, which set no calorie limit, weight at 6 months was 10.6 kilograms lower than with usual care and body mass index 3.9 points lower (Wright et al., 2017). In the 8-week breast cancer trial, women on the diet lost 9 pounds more than controls (T. M. Campbell et al., 2024), and in the Plants for Joints trial described below, weight at 16 weeks was 3.9 kilograms lower than with usual care (Walrabenstein et al., 2023). In the 4-week feeding trial, where calories were set to hold weight steady, weight fell 0.8 percent on the typical diet and 1.3 percent on the plant-based diet (Lessard-Lord et al., 2026).

Mortality

None of the trials found for this page was designed to measure deaths, and none reported deaths from any cause as an outcome. The trials reviewed here do not establish an effect of the diet on length of life in either direction. Trials of the Ornish program, which combines a very low fat diet with exercise and stress management, are a separate body of evidence that this page did not review.

Other conditions studied

In the Plants for Joints trial in the Netherlands, 83 adults with rheumatoid arthritis were randomized to usual care or a 16-week program of a whole-food plant-based diet, physical activity, and stress and sleep coaching, with vitamin B12 and vitamin D supplements, and 77 completed it. Disease activity on the DAS28 score improved by 0.90 points more than with usual care, from 0.41 to 1.29 (Walrabenstein et al., 2023). Because the diet was one of several parts, the trial cannot say how much came from the diet. A German trial of a plant-based diet its authors did not describe as whole-food, begun after a 7-day fast and followed for 11 weeks, did not demonstrate a difference in physical function from standard German dietary guidance in 53 adults with rheumatoid arthritis (Hartmann et al., 2022).

Eating behavior and wellbeing

In the breast cancer trial, the women on the diet reported better thinking, by 16.1 points on the FACT-Cog scale, from 0.8 to 31.7, and better emotional wellbeing than controls; the control group received less time and attention from the study team, which may explain part of that difference (E. K. Campbell, Campbell, et al., 2024).

Evidence from long-term prospective cohort studies

A cohort study follows people who already eat a certain way and records what happens to them. It can show that a pattern goes with an outcome; it cannot by itself show that the pattern caused it. Very few people in the large cohorts ate a whole-food plant-based diet in its strict sense, so researchers built scores that rank everyone's ordinary diet by how far it leans toward plant foods, and toward which plant foods.

The best known are the 3 plant-based diet indices developed at Harvard. Each person's intake of 18 food groups is ranked against everyone else's in the cohort and given 1 to 5 points, for a total of 18 to 90. The healthy plant groups are whole grains, fruits, vegetables, nuts, legumes, vegetable oils, and tea and coffee; the less healthy plant groups are fruit juices, sugar-sweetened beverages, refined grains, potatoes, and sweets and desserts; and the animal groups are animal fats, dairy, eggs, fish and seafood, meat, and miscellaneous animal-based foods (Satija et al., 2016).

The overall plant-based diet index rewards all 12 plant groups and penalizes the 6 animal groups. The healthful plant-based diet index rewards the 7 healthy plant groups and penalizes the less healthy plant groups and the animal groups. The unhealthful plant-based diet index does the opposite for plant foods, rewarding the 5 less healthy groups and penalizing the 7 healthy ones, and also penalizes animal foods. All 3 penalize every animal food, fish and yogurt included (Satija et al., 2016).

Two things follow for anyone reading this research. First, the scores are relative: a high score means eating more plants and fewer animal foods than others in the same cohort, not meeting a fixed definition. In the Harvard cohorts, the authors report that people in the highest tenth of the healthful index still ate about 4 servings of animal foods a day, against 5 to 6 in the lowest tenth (Satija et al., 2016), and in a U.S. community cohort the highest fifth of the overall index ate an average of 3.6 servings a day (Kim, Caulfield, Garcia-Larsen, Steffen, Coresh, & Rebholz, 2019).

Second, which plant foods count as "healthy" was the authors' own judgment, which they describe as having "an element of subjectivity" (Satija et al., 2016). Some later studies changed the recipe, for example dropping vegetable oils, so scores are not always comparable across studies (Kim, Caulfield, Garcia-Larsen, Steffen, Coresh, & Rebholz, 2019; Thompson et al., 2023).

Cardiometabolic outcomes

Type 2 diabetes. In 200,727 U.S. health professionals in 3 cohorts, with 16,162 new cases over 4.1 million person-years, people in the highest tenth of the healthful index had a lower rate of type 2 diabetes than those in the lowest tenth, a hazard ratio of 0.66, from 0.61 to 0.72, after adjusting for body mass index, and 0.83 for each 10-point increase. The overall index showed a weaker association, 0.80, and the unhealthful index a higher rate, 1.16, from 1.08 to 1.25 (Satija et al., 2016).

Among the same cohorts, people whose overall or healthful index fell by more than 10 percent over 4 years had a 12 to 23 percent higher rate of diabetes in the next 4 years than people whose score stayed stable, after adjusting for starting body mass index and for changes in other habits. This is an association with a change in score, not a test of changing the diet (Chen et al., 2021).

A 2025 meta-analysis pooled 11 cohort studies of the healthful index from the U.S., Europe and Asia and found a relative risk of 0.75, from 0.69 to 0.82, highest against lowest; the review's abstract and text give different estimates, and this page uses the text (Murciano et al., 2025). Its pooled estimate for the unhealthful index, 1.27, from 1.00 to 1.60, came from 7 studies that did not include the 3 Harvard cohorts. A 2023 meta-analysis by the Harvard group also reported index analyses, but its diabetes totals combine current adherence with changes in adherence, including repeated use of the Harvard cohorts, so those totals are not used here (Wang et al., 2023).

Heart disease and stroke. In 209,298 U.S. health professionals with 8,631 new cases of coronary heart disease over up to 28 years, those in the highest tenth of the healthful index had a hazard ratio of 0.75, from 0.68 to 0.83, against the lowest tenth, and those in the highest tenth of the unhealthful index 1.32, from 1.20 to 1.46; the overall index showed little association, 0.92, from 0.83 to 1.01 (Satija et al., 2017). In UK Biobank, the highest quarter of the healthful index went with fewer heart attacks, 0.86, from 0.78 to 0.95, and the highest quarter of the unhealthful index with more, 1.17, from 1.06 to 1.29 (Thompson et al., 2023).

Pooled across cohorts, the Harvard group's 2023 meta-analysis found a relative risk of 0.85 for any cardiovascular disease with the healthful index, from 0.80 to 0.92. Its pooled figure for the unhealthful index counts some of the same Harvard participants twice, once for heart disease and once for stroke, so it is not used here (Wang et al., 2023). For stroke, the healthful index showed a weaker association in the Harvard cohorts, highest against lowest fifth 0.90, from 0.83 to 0.98; for ischemic stroke alone the association, 0.92, from 0.82 to 1.04, was not statistically clear, and none was found for hemorrhagic stroke (Baden et al., 2021).

The findings are not uniform. In 12,168 middle-aged adults in 4 U.S. communities followed for a median of 25 years, the overall index was associated with less cardiovascular disease, 0.84, but the healthful index was not clearly associated with new cardiovascular disease, 0.91, from 0.82 to 1.01, and the unhealthful index showed no association (Kim, Caulfield, Garcia-Larsen, Steffen, Coresh, & Rebholz, 2019). In 3,635 African American adults in the Jackson Heart Study in Mississippi, none of the 3 indices was associated with cardiovascular disease or death, and even those with the most plant-rich diets "still regularly included animal-based foods" (Weston et al., 2022).

Cancer

A 2026 meta-analysis of 19 cohort studies pooled the indices against specific cancers and rated the certainty of each association using GRADE. For each 10-point increase in the healthful index, the hazard ratio for breast cancer was 0.94, from 0.93 to 0.96, rated moderate, and for colorectal cancer 0.95, from 0.92 to 0.98, rated low, from 5 cohort estimates, 2 of which are the men and the women of a single cohort; the unhealthful index went with a slightly higher risk of breast cancer, 1.03, from 1.01 to 1.06, rated low (Gil-Lespinard et al., 2026).

The review disagrees with itself about the GRADE starting level, moderate in its main text and low in its supplement, and about heterogeneity, and its breast cancer sensitivity table gives a different confidence interval, 0.92 to 0.97. These discrepancies prevent this page from independently checking the published certainty labels, so they are reported as the authors' labels.

In 126,394 UK Biobank participants followed for about 11 years, those in the highest quarter of the healthful index had a slightly lower rate of cancer than those in the lowest quarter, 0.93, from 0.88 to 0.99, and those in the highest quarter of the unhealthful index a higher rate, 1.10, from 1.03 to 1.17 (Thompson et al., 2023).

Body weight, as measured

In 3 U.S. cohorts of 126,982 adults, each 1 standard deviation increase in the healthful index over 4-year periods went with 0.68 kilograms less weight gain, and each increase in the unhealthful index with 0.36 kilograms more; this page read that study's abstract (Satija et al., 2019). In the cohort analyses of disease above, body mass index was usually treated as something to adjust for, and the authors of the diabetes study note that adjusting for it may underestimate the diet's full association, because weight may be one of the pathways (Satija et al., 2016).

Mortality

A 2025 meta-analysis of 11 cohort studies with 977,763 participants found that, against the lowest scores, the highest scores on the healthful index went with a 14 percent lower rate of death from any cause, a hazard ratio of 0.86, from 0.81 to 0.92, and on the overall index 0.85, from 0.80 to 0.90, while the highest scores on the unhealthful index went with a 20 percent higher rate, 1.20, from 1.11 to 1.31. For death from cardiovascular disease the figures were 0.83, 0.81 and 1.19 (Mo et al., 2025). One entry in the review's study table names the wrong cohort for a Korean study.

Change matters in the same direction. Among 49,407 women and 25,907 men in 2 of the Harvard cohorts, each 10-point increase in the healthful index over the previous 12 years went with a 10 percent lower rate of death over the following years, a hazard ratio of 0.90, from 0.88 to 0.93, and each 10-point increase in the unhealthful index with a 9 percent higher rate, 1.09, from 1.06 to 1.12 (Baden et al., 2019).

In UK Biobank, the highest quarter of the healthful index went with a hazard ratio of 0.84 for death, from 0.78 to 0.91, and of the unhealthful index 1.23, from 1.14 to 1.32 (Thompson et al., 2023). In a national U.S. survey cohort of 11,879 adults, neither the overall nor the unhealthful index was associated with death, and the healthful index showed a nonlinear association: above the median score, each 10-point increase went with a lower rate of death, a hazard ratio of 0.95, from 0.91 to 0.98 (Kim et al., 2018).

Highlighted studies

These 4 studies carry the most weight for this page: 2 cohort analyses that established the indices and their link with disease and death, and 2 randomized trials of whole-food plant-based programs, the largest in type 2 diabetes found for this page and the BROAD trial. Each is described so a reader can judge it without opening the paper.

On a narrow screen, scroll the table sideways to see every column.

Highlighted studies for the Whole-Food Plant-Based Diet

Study	Design	Sample size	Duration	Finding	The limitation that matters
Satija et al., 2016, Nurses' Health Study, Nurses' Health Study II and Health Professionals Follow-Up Study	Prospective cohort analysis of 3 cohorts	200,727 U.S. health professionals; 16,162 new cases of type 2 diabetes	About 20 to 28 years, depending on the cohort	Highest against lowest tenth of the healthful index: hazard ratio 0.66 (0.61 to 0.72) for type 2 diabetes; unhealthful index 1.16 (1.08 to 1.25)	An association in mostly White health professionals who mostly still ate animal foods; the index ranks diets within the cohort and was not a test of following a whole-food plant-based diet
Baden et al., 2019, Nurses' Health Study and Health Professionals Follow-Up Study	Prospective cohort analysis of change in diet	75,314 women and men free of heart disease and cancer	12 years of diet change, then 16 years of follow-up for deaths	Each 10-point increase in the healthful index: hazard ratio 0.90 (0.88 to 0.93) for death from any cause; unhealthful index 1.09 (1.06 to 1.12)	People who improved their diets may also have changed other habits; residual confounding cannot be excluded
Hanick et al., 2025, Republic of the Marshall Islands	Randomized controlled trial, program against standard medical care	169 adults with type 2 diabetes randomized; 136 analyzed	24 weeks, with support for the first 12	HbA1c 8 mmol/mol (0.7 percentage points) lower at 24 weeks, from 1 to 14; more participants reduced diabetes medicine	Diet was combined with exercise and intensive classes, no diet records were kept, and 31 people withdrew before baseline
Wright et al., 2017, the BROAD trial (New Zealand)	Randomized controlled trial, program plus usual care against usual care	65 adults with overweight or obesity and a cardiometabolic condition; 49 at 6 months	12-week program, measured at 6 months	HbA1c 5 mmol/mol lower and body mass index 3.9 points lower than usual care; total cholesterol difference not statistically clear	Small, one general practice, unblinded, a strict oil-free version, and a quarter of participants did not complete it

Head to head

Few studies have compared a whole-food plant-based diet directly with another named diet. Against the DASH pattern, the only comparison found for this page was the small nonrandomized study in insulin-treated type 2 diabetes described above: insulin needs were lower at the end of the whole-food plant-based week than after the first DASH week, a ratio of 0.81, from 0.70 to 0.94, but the difference from the second DASH week was not statistically clear, and the authors state that carryover between weeks prevents the effects of the 2 diets from being separated (T. M. Campbell et al., 2023). The DASH Diet page covers that pattern's own trials.

Against a typical North American diet, the 4-week feeding trial found LDL cholesterol 17.9 percent lower (Lessard-Lord et al., 2026). Against the Mediterranean Diet and an American Heart Association diet, the 1-year trial in children and their parents described in section 3 did not demonstrate an advantage of any of the 3 diets in the children, and only a third of the pairs completed the 52-week visit (Macknin et al., 2021). In older adults with mild cognitive impairment, counseling on the diet was compared with counseling on a healthy omnivorous diet; the report found for this page covers only eating habits (Hanslian et al., 2025).

The American Heart Association's 2023 comparison of popular patterns, a scoring exercise rather than a trial, placed vegetarian, Mediterranean, DASH and pescetarian patterns in its top tier, vegan patterns in its second tier, and very low fat patterns that avoid oils, nuts and seeds in its third, because they restrict foods its guidance emphasizes (Gardner et al., 2023).

Where the evidence is absent

The searches for this page did not identify a randomized trial of a whole-food plant-based diet that measured heart attacks, strokes, new cancers or deaths; the studies reviewed here do not establish an effect on those outcomes in either direction. The randomized trials found ran from 15 days to 1 year, most enrolled fewer than 100 people, and most tested the diet together with exercise, classes, provided meals or other lifestyle changes. The claims of disease reversal rest on uncontrolled case series and small trials that this page did not find replicated in larger ones.

The long-term evidence uses scores that rank ordinary diets, in cohorts where few people ate no animal foods, mostly White health professionals in the U.S. and adults in the UK; in an African American cohort the associations were not found. The searches identified no randomized trial of the diet in pregnancy, in athletes or in people with a history of an eating disorder; the evidence for those groups comes from cohort studies of diet scores, cross-sectional studies, or studies of vegetarian and vegan diets.

For children, older adults and people with kidney disease, the trials found are few and narrow: a 1-year trial in children selected for raised cholesterol, a counseling trial in older adults with mild cognitive impairment whose report found for this page covers only eating habits, and a 15-day pilot in 43 adults with kidney disease (Hanslian et al., 2025; Liebman et al., 2025; Macknin et al., 2021). They do not establish safety or benefit for those groups in general.

5. Mechanisms

(optional reading; select the heading to open or close this section)

This section explains how the diet is thought to work in the body. You can skip it. Nothing in the coaching sections depends on it.

Established mechanisms

The best-documented effect in the trials found for this page is on blood cholesterol. Eating less saturated fat, which comes mostly from animal foods and tropical oils, and more unsaturated fat from plants lowers LDL cholesterol; the American Heart Association states that "strong evidence shows that replacing butter with plant oils and spreads containing predominantly unsaturated fat decreases low-density lipoprotein cholesterol concentrations" (Lichtenstein et al., 2026). In the feeding trial that held weight steady, the whole-food plant-based diet lowered LDL cholesterol by 17.9 percent and apolipoprotein B, the protein on the particles that carry cholesterol into artery walls, by 14.8 percent; HDL cholesterol also fell, by 8.5 percent (Lessard-Lord et al., 2026).

The second is fiber. Modeled whole-food plant-based menus supplied about 70 grams of fiber a day, against 28 grams for a federal MyPlate menu (Karlsen et al., 2019), and dietary patterns rich in fiber are associated with less cardiovascular disease, type 2 diabetes and colorectal cancer (Lichtenstein et al., 2026). The third is practical rather than biological: when blood sugar falls with a change in eating, medicines that lower blood sugar can push it too low, which is why the trials described in section 4 reduced insulin and other diabetes medicines under a protocol (T. M. Campbell et al., 2023; Hanick et al., 2025).

Proposed mechanisms

Several explanations are plausible but not established by the studies found for this page. Weight fell in BROAD, which set no calorie limit, which suggests people ate less (Wright et al., 2017). Some trials collected self-reported dietary intake, which cannot precisely establish changes in energy intake, and the Marshall Islands trial collected no diet records (Hanick et al., 2025). In the small nonrandomized study in insulin-treated type 2 diabetes, insulin resistance measured from fasting blood tests was 49 percent lower after the whole-food plant-based week, a change that may reflect the diet, the preceding DASH week, or both (T. M. Campbell et al., 2023). In the Marshall Islands trial, C-reactive protein, a marker of inflammation, was lower at 24 weeks in the program group (Hanick et al., 2025); a change in a marker is not a change in disease.

The cohort researchers propose that refined grains, potatoes, sugary drinks and sweets explain why a high score on the unhealthful index goes with more disease even though those foods come from plants (Satija et al., 2017). Campbell's argument that animal protein promotes cancer rests largely on his own experiments in rats and mice fed the milk protein casein (T. C. Campbell, 2024); a finding in animals is a reason to study a question in people, not evidence that a diet prevents cancer in them. A proposed mechanism never supports a claim in section 4.

6. Risks, contraindications and myths

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Warnings from professional or regulatory bodies

The searches for this page found no warning from a professional or regulatory body about whole-food plant-based eating as such. The American Heart Association's review of popular diets does caution about the 2 kinds of pattern the strict versions belong to. Of vegan patterns, it says that restricting foods its guidance emphasizes "places adults following vegan patterns at risk for macronutrient and micronutrient deficiencies, particularly vitamin B12 deficiency," and that "referral to a registered dietitian or other qualified health professional is encouraged." Of very low fat patterns, which avoid oils, nuts and seeds, it says that "medical supervision of more restrictive very low-fat patterns is advised to reduce the likelihood of micronutrient deficiency or, in the cases of very low-fat vegan patterns, deficiencies in protein and essential fatty acids" (Gardner et al., 2023).

The Academy of Nutrition and Dietetics' position is that, in adults, "appropriately planned vegetarian and vegan dietary patterns can be nutritionally adequate and can offer long-term health benefits," with dietitians playing "a pivotal role" in planning them (Raj et al., 2026). The position covers adults who are not pregnant or breastfeeding.

Nutrient gaps

Which gaps apply depends on the version. A plant-predominant version that keeps some fish, eggs or dairy has fewer of them; a version with no animal foods has the gaps that the Vegan Diet page describes in detail. The points below are the ones that apply most to the whole-food versions.

A diet with no animal foods cannot supply vitamin B12 without fortified foods or a supplement, because unfortified plant foods do not contain significant amounts of its active form (Craig et al., 2021). The National Institutes of Health lists people who follow vegetarian diets, and the infants of women who follow vegan diets, among the groups at risk of deficiency, and sets the adult Recommended Dietary Allowance at 2.4 to 2.8 micrograms a day (National Institutes of Health, Office of Dietary Supplements, 2025). The College's own article describes the diet as one that excludes animal foods "with certain selective supplementation of vitamins B12" (American College of Lifestyle Medicine, 2023).

In the BROAD trial, which supplied 50 micrograms a day, 2 participants still developed low B12 levels, which returned to normal with supplementation (Wright et al., 2017). Modeled whole-food plant-based menus met the B12 requirement only with a supplement (Karlsen et al., 2019).

Vitamin D and calcium. The same modeled menus supplied almost no vitamin D from food, about 1 microgram a day on average. They averaged about 959 milligrams of calcium a day; the paper's text and tables disagree about whether this met the recommendation for men, so the model should not be taken as assurance of adequate calcium (Karlsen et al., 2019). Guidance for health professionals notes that calcium is absorbed well from low-oxalate greens such as kale, bok choy and broccoli and poorly from spinach, and that a vitamin D supplement may be needed (Craig et al., 2021).

Iodine, omega-3 fats, iron and zinc also need planning in a version with no animal foods, and the Vegan Diet page sets out each of them. Whether a particular plan meets a particular person's needs is a question for a registered dietitian.

Who should not follow it without medical supervision

People taking insulin, a sulfonylurea or other medicine that can cause low blood sugar, because the dose may need to fall quickly (Hanick et al., 2025; Wright et al., 2017); people taking blood pressure medicine (T. M. Campbell et al., 2024); and people taking warfarin (American Society of Health-System Pharmacists, 2026). People with kidney disease, whose kidney care team sets the plan. People who are pregnant or breastfeeding, children and teenagers, and older adults with a small appetite or low body weight, whose needs are higher or more particular (Craig et al., 2021). And people with a history of disordered eating. The special populations list in section 3 is built from this list.

Medication interactions

A coach never adjusts medication. The point of knowing these is to know when to send a client back to the prescriber. Insulin and sulfonylureas lower blood sugar regardless of what is eaten, so a large change toward this diet can cause low blood sugar unless doses are adjusted; in BROAD, one participant had low blood sugar from the first week and his doctor reduced and then stopped his insulin (Wright et al., 2017), and in the Marshall Islands trial participants on insulin were told to reduce their dose when blood sugar fell below 70 mg/dL or they had symptoms (Hanick et al., 2025).

Blood pressure can also fall; 3 women in the breast cancer trial, 2 of them on blood pressure medicine, had symptomatic low blood pressure and were referred for medicine adjustment (T. M. Campbell et al., 2024), and in a 15-day pilot in adults with kidney disease, 3 people in the program had symptoms of low blood pressure (Liebman et al., 2025).

For warfarin, the patient information advises people to "eat consistent amounts of vitamin K-containing food on a week-to-week basis," not to eat large amounts of leafy green vegetables or certain vegetable oils high in vitamin K, and to "talk to your doctor before you make any changes in your diet" (American Society of Health-System Pharmacists, 2026). A client on warfarin keeps the prescriber informed before a large change in eating.

Signs it is going wrong

Physical signs a coach or a family member might notice include the signs of low blood sugar that a person's own diabetes plan describes, in someone on diabetes medicine; dizziness or lightheadedness, especially on standing, in someone on blood pressure medicine; tiredness that does not lift after months or years without a B12 source; and weight the person did not mean to lose. For possible low blood sugar, the client follows their own diabetes plan immediately, with emergency help for severe symptoms or an episode they cannot manage, then tells the prescriber. The other signs are brought to the clinician, who works out the cause; none of them is a diagnosis.

Behavior matters as much and has to be read with care. Reading labels and cooking from scratch are ordinary on this diet. A list of permitted foods that keeps shrinking, distress or guilt after a meal with oil or cheese, or avoiding meals with others carries more meaning and is worth asking about: what the rule is for, whether it causes distress, whether it is narrowing what the person eats, and whether it is getting in the way of daily life. Where the answers raise a real concern about disordered eating, the coach follows their own referral process.

Myths and where they came from

Myth: "If it's plant-based, it's healthy."

Where it came from: the general good reputation of plant foods, and the wide use of "plant-based" as a marketing label. What is true: in cohort studies that separated healthful from unhealthful plant foods, diets high in refined grains, potatoes, sugary drinks and sweets went with more coronary heart disease, not less (Satija et al., 2017), and the American Heart Association notes that many plant-based meat alternatives are ultraprocessed (Lichtenstein et al., 2026). The word "whole" carries much of the meaning.

Myth: "Research has proven this diet reverses heart disease and diabetes."

Where it came from: the College's position, which places the diet on a continuum from prevention to "treatment and reversal," and physicians' reports of their own patients, such as Esselstyn's case series (American College of Lifestyle Medicine, n.d.; Esselstyn, 2017). What is true: most of the randomized trials found for this page lasted 6 months or less, the longest followed families for 1 year, and they combined the diet with other changes, and measured blood tests, weight and medicine use, not heart attacks or deaths. In the Marshall Islands trial in type 2 diabetes, HbA1c was lower and more people reduced their medicines, and 8 percent of the program group met the trial's definition of remission, against none with standard care (Hanick et al., 2025). The American Heart Association notes that "observational studies and smaller randomized trials" showing "stabilization and potential reversal" of atherosclerosis may motivate some people to follow very low fat diets (Gardner et al., 2023).

Myth: "A whole-food diet supplies everything, so no supplements are needed."

Where it came from: the reasonable idea that whole foods carry more nutrients than refined ones. What is true: a diet with no animal foods needs a reliable source of vitamin B12, and often vitamin D, from fortified foods or supplements; even the College's own description includes B12 supplementation (American College of Lifestyle Medicine, 2023; National Institutes of Health, Office of Dietary Supplements, 2025).

Myth: "You have to combine proteins at every meal to get complete protein."

Where it came from: older advice about pairing grains and beans in the same meal. What is true: guidance for health professionals states that "there is no need for different protein foods to be combined in one meal," provided a variety of plant foods is eaten each day (Craig et al., 2021), and modeled whole-food plant-based menus supplied 16 percent of energy as protein (Karlsen et al., 2019). Individual protein needs, especially in older age, illness or training, are a dietitian's question.

7. Key terms

Whole-food plant-based diet

An eating pattern built mostly or entirely on whole or minimally processed plant foods; sources differ on whether it excludes all animal foods and added oils.

Minimally processed food

A food that has been washed, cut, cooked, frozen, canned or ground but still contains what the original plant or animal contained.

Plant-predominant

A pattern in which plant foods make up most of the diet and small amounts of animal foods are allowed; the American College of Lifestyle Medicine uses the term for its nutrition pillar.

Vegan diet

An eating pattern that excludes all foods of animal origin, whether or not the remaining foods are whole or processed.

Very low fat diet

A pattern with about 10 percent or less of energy from fat that avoids added oils and often nuts and seeds, as in several oil-free whole-food plant-based programs.

Plant-based diet index

A score that ranks each person's usual diet, within a study, by how much it leans toward plant foods and away from animal foods.

Healthful plant-based diet index

A version of the score that rewards whole grains, fruits, vegetables, nuts, legumes, vegetable oils, and tea and coffee, and penalizes less healthy plant foods and animal foods.

Unhealthful plant-based diet index

A version of the score that rewards fruit juices, sugary drinks, refined grains, potatoes and sweets, and penalizes healthy plant foods and animal foods.

Prospective cohort study

A study that records what people eat and then follows them for years to see what happens; it shows associations, not cause and effect.

Hazard ratio

A comparison of how often an outcome occurs over time in one group against another; 0.75 means 25 percent less often.

HbA1c

A blood test that reflects average blood sugar over recent months; the main outcome in diabetes trials.

LDL cholesterol

The cholesterol carried in low-density lipoprotein particles, a cause of the artery disease behind most heart attacks.

Vitamin B12

A vitamin made by microorganisms and found naturally in animal foods; a diet with no animal foods needs fortified foods or a supplement to supply it.

GRADE

The 4-level scale used in clinical guidelines to say how certain the evidence for a conclusion is: high, moderate, low or very low. It rates the evidence for one outcome and one comparison at a time, not the diet.

8. Review questions

1. Using section 1, explain in 3 or 4 sentences how a whole-food plant-based diet differs from a vegan diet, and name 2 points on which the sources that define it disagree.
2. Using section 4, describe what the healthful and unhealthful plant-based diet indices score, and explain why a person in the highest tenth of the healthful index may still eat animal foods every day.
3. Using section 4, describe the Marshall Islands trial: who took part, what the program included, what it was compared with, how long it lasted, and what it found for HbA1c. Why can it not tell you how much of the result came from the diet alone?
4. A client says, "I take insulin, and I'm going fully plant-based tomorrow, no oil, no animal foods." Write what you would say and ask, and say exactly where the referral line is and why.
5. Where does the belief that anything plant-based is healthy come from, and what did the cohort studies that separated healthful from unhealthful plant foods find? Write the 2 sentences you would use if a client raised it.

9. References

American College of Lifestyle Medicine. (n.d.). Recommendations and standards. Retrieved October 4, 2026, from lifestylemedicine.org/about-aclm/research-and-quality/recommendations-standards/

American College of Lifestyle Medicine. (2018, September 25). American College of Lifestyle Medicine announces dietary lifestyle position statement for treatment and potential reversal of disease [Press release]. PRWeb. prweb.com/releases/american_college_of_lifestyle_medicine_announces_dietary_lifestyle_position_statement_for_treatment_and_potential_reversal_of_disease/prweb15786205.htm

American College of Lifestyle Medicine. (2023, March 1). The benefits of plant-based nutrition. lifestylemedicine.org/benefits-plant-based-nutrition/

American Society of Health-System Pharmacists. (2026). Warfarin. MedlinePlus, National Library of Medicine. medlineplus.gov/druginfo/meds/a682277.html

Baden, M. Y., Liu, G., Satija, A., Li, Y., Sun, Q., Fung, T. T., Rimm, E. B., Willett, W. C., Hu, F. B., & Bhupathiraju, S. N. (2019). Changes in plant-based diet quality and total and cause-specific mortality. Circulation, 140(12), 979-991. https://doi.org/10.1161/CIRCULATIONAHA.119.041014

Baden, M. Y., Shan, Z., Wang, F., Li, Y., Manson, J. E., Rimm, E. B., Willett, W. C., Hu, F. B., & Rexrode, K. M. (2021). Quality of plant-based diet and risk of total, ischemic, and hemorrhagic stroke. Neurology, 96(15), e1940-e1953. https://doi.org/10.1212/WNL.0000000000011713

Bazshahi, E., Pourreza, S., Jayedi, A., Mirmohammadkhani, M., Emadi, A., & Shab-Bidar, S. (2024). Adherence to plant-based diet during pregnancy and risk of gestational diabetes: A prospective birth cohort study. BMC Nutrition, 10, Article 139. https://doi.org/10.1186/s40795-024-00949-4

Campbell, E. K., Campbell, T. M., Culakova, E., Blanchard, L., Wixom, N., Guido, J. J., Fetten, J., Huston, A., Shayne, M., Janelsins, M. C., Mustian, K. M., Moore, R. G., & Peppone, L. J. (2024). A whole food, plant-based randomized controlled trial in metastatic breast cancer: Feasibility, nutrient, and patient-reported outcomes. Breast Cancer Research and Treatment, 206(2), 273-283. https://doi.org/10.1007/s10549-024-07284-z

Campbell, E. K., Taillie, L., Blanchard, L. M., Wixom, N., Harrington, D. K., Peterson, D. R., Wittlin, S. D., & Campbell, T. M. (2024). Post hoc analysis of food costs associated with Dietary Approaches to Stop Hypertension diet, whole food, plant-based diet, and typical baseline diet of individuals with insulin-treated type 2 diabetes mellitus in a nonrandomized crossover trial with meals provided. The American Journal of Clinical Nutrition, 119(3), 769-778. https://doi.org/10.1016/j.ajcnut.2023.12.023

Campbell, T. C. (2024). Nutrition, lifestyle, and environment. In J. M. Rippe (Ed.), Lifestyle medicine (4th ed., pp. 138-144). CRC Press. https://doi.org/10.1201/9781003227793-13

Campbell, T. M., Campbell, E. K., Attia, J., Ventura, K., Mathews, T., Chhabra, K. H., Blanchard, L. M., Wixom, N., Faniyan, T. S., Peterson, D. R., Harrington, D. K., & Wittlin, S. D. (2023). The acute effects of a DASH diet and whole food, plant-based diet on insulin requirements and related cardiometabolic markers in individuals with insulin-treated type 2 diabetes. Diabetes Research and Clinical Practice, 202, Article 110814. https://doi.org/10.1016/j.diabres.2023.110814

Campbell, T. M., Campbell, E. K., Culakova, E., Blanchard, L. M., Wixom, N., Guido, J. J., Fetten, J., Huston, A., Shayne, M., Janelsins, M. C., Mustian, K. M., Moore, R. G., & Peppone, L. J. (2024). A whole-food, plant-based randomized controlled trial in metastatic breast cancer: Weight, cardiometabolic, and hormonal outcomes. Breast Cancer Research and Treatment, 205(2), 257-266. https://doi.org/10.1007/s10549-024-07266-1

Chen, Z., Drouin-Chartier, J.-P., Li, Y., Baden, M. Y., Manson, J. E., Willett, W. C., Voortman, T., Hu, F. B., & Bhupathiraju, S. N. (2021). Changes in plant-based diet indices and subsequent risk of type 2 diabetes in women and men: Three U.S. prospective cohorts. Diabetes Care, 44(3), 663-671. https://doi.org/10.2337/dc20-1636

Cholesterol Treatment Trialists' (CTT) Collaboration. (2010). Efficacy and safety of more intensive lowering of LDL cholesterol: A meta-analysis of data from 170 000 participants in 26 randomised trials. The Lancet, 376(9753), 1670-1681. https://doi.org/10.1016/S0140-6736(10)61350-5

Craig, W. J., Mangels, A. R., Fresán, U., Marsh, K., Miles, F. L., Saunders, A. V., Haddad, E. H., Heskey, C. E., Johnston, P., Larson-Meyer, E., & Orlich, M. (2021). The safe and effective use of plant-based diets with guidelines for health professionals. Nutrients, 13(11), Article 4144. https://doi.org/10.3390/nu13114144

Díaz-Goñi, V., Bizzozero-Peroni, B., Visier-Alfonso, M. E., Jiménez-López, E., Fernández-Rodríguez, R., López-Gil, J. F., Martins-de-Passos, T. O., González, A. D., Martínez-Vizcaíno, V., & Mesas, A. E. (2026). The associations between vegetarian and vegan diets and orthorexia nervosa symptoms in adults: A systematic review and meta-analysis. International Journal of Eating Disorders, 59(3), 409-423. https://doi.org/10.1002/eat.24596

Esselstyn, C. B. (2017). A plant-based diet and coronary artery disease: A mandate for effective therapy. Journal of Geriatric Cardiology, 14(5), 317-320. https://doi.org/10.11909/j.issn.1671-5411.2017.05.004. Full text: pmc.ncbi.nlm.nih.gov/articles/PMC5466936/

Gardner, C. D., Vadiveloo, M. K., Petersen, K. S., Anderson, C. A. M., Springfield, S., Van Horn, L., Khera, A., Lamendola, C., Mayo, S. M., & Joseph, J. J. (2023). Popular dietary patterns: Alignment with American Heart Association 2021 dietary guidance: A scientific statement from the American Heart Association. Circulation, 147(22), 1715-1730. https://doi.org/10.1161/CIR.0000000000001146

Gil-Lespinard, M., Iglesias-Vázquez, L., & Jakszyn, P. (2026). Healthful and unhealthful plant-based diets and site-specific cancer risk: A systematic review and meta-analysis of observational studies. European Journal of Nutrition, 65(4), Article 121. https://doi.org/10.1007/s00394-026-03948-2

Hanick, C. J., Peterson, C. M., Davis, B. C., Sabaté, J., & Kelly, J. H. (2025). A whole-food, plant-based intensive lifestyle intervention improves glycaemic control and reduces medications in individuals with type 2 diabetes: A randomised controlled trial. Diabetologia, 68(2), 308-319. https://doi.org/10.1007/s00125-024-06272-8

Hanslian, E., Dell'Oro, M., Schiele, J. K., Kandil, F. I., Hasanbasic, D., Henn, C., Graessel, E., Scheuermann, J.-S., Scheerbaum, P., Michalsen, A., Jeitler, M., & Kessler, C. S. (2025). Effects of nutritional counseling on dietary patterns in patients with mild cognitive impairment: Insights from the BrainFit-Nutrition study. Frontiers in Nutrition, 12, Article 1536939. https://doi.org/10.3389/fnut.2025.1536939

Hartmann, A. M., Dell'Oro, M., Spoo, M., Fischer, J. M., Steckhan, N., Jeitler, M., Häupl, T., Kandil, F. I., Michalsen, A., Koppold-Liebscher, D. A., & Kessler, C. S. (2022). To eat or not to eat: An exploratory randomized controlled trial on fasting and plant-based diet in rheumatoid arthritis (NutriFast-Study). Frontiers in Nutrition, 9, Article 1030380. https://doi.org/10.3389/fnut.2022.1030380

Jancsura, M. K., Grobman, W. A., Wu, J., Griffis, H. M., Wirth, M. D., Haas, D. M., Silver, R. M., Feghali, M. N., Reddy, U. M., Levine, L., Saade, G., Yee, L. M., Lindsay, K. L., & Venkatesh, K. K. (2026). Association between a periconception healthy plant-based diet and adverse pregnancy outcomes. The Journal of Nutrition, 156(6), Article 101577. https://doi.org/10.1016/j.tjnut.2026.101577

Karlsen, M. (2026, February 9). ACLM releases updated dietary position statement. American College of Lifestyle Medicine. lifestylemedicine.org/aclm-releases-updated-dietary-position-statement/

Karlsen, M. C., Rogers, G., Miki, A., Lichtenstein, A. H., Folta, S. C., Economos, C. D., Jacques, P. F., Livingston, K. A., & McKeown, N. M. (2019). Theoretical food and nutrient composition of whole-food plant-based and vegan diets compared to current dietary recommendations. Nutrients, 11(3), Article 625. https://doi.org/10.3390/nu11030625

Kim, H., Caulfield, L. E., Garcia-Larsen, V., Steffen, L. M., Coresh, J., & Rebholz, C. M. (2019). Plant-based diets are associated with a lower risk of incident cardiovascular disease, cardiovascular disease mortality, and all-cause mortality in a general population of middle-aged adults. Journal of the American Heart Association, 8(16), Article e012865. https://doi.org/10.1161/JAHA.119.012865

Kim, H., Caulfield, L. E., Garcia-Larsen, V., Steffen, L. M., Grams, M. E., Coresh, J., & Rebholz, C. M. (2019). Plant-based diets and incident CKD and kidney function. Clinical Journal of the American Society of Nephrology, 14(5), 682-691. https://doi.org/10.2215/CJN.12391018

Kim, H., Caulfield, L. E., & Rebholz, C. M. (2018). Healthy plant-based diets are associated with lower risk of all-cause mortality in US adults. The Journal of Nutrition, 148(4), 624-631. https://doi.org/10.1093/jn/nxy019

Krenek, A. M., Mathews, A., Guo, J., Courville, A. B., Pepine, C. J., Chung, S. T., & Aggarwal, M. (2024). Recipe for heart health: A randomized crossover trial on cardiometabolic effects of extra virgin olive oil within a whole-food plant-based vegan diet. Journal of the American Heart Association, 13(15), Article e035034. https://doi.org/10.1161/JAHA.124.035034

Lessard-Lord, J., Guay, V., Rancourt-Bouchard, M., Couture, P., Gangloff, A., Blais, J., Tremblay, A. J., Greffard, K., Bilodeau, J.-F., Rudkowska, I., & Drouin-Chartier, J.-P. (2026). Impact of a whole food, plant-based diet on LDL-cholesterol and cardiovascular risk factors in adults with heterozygous familial hypercholesterolemia: A randomized, two-period, two-treatment, crossover, fully controlled feeding trial. Nature Communications, 17, Article 6632. https://doi.org/10.1038/s41467-026-73468-4

Leung, H., Acosta, P. F. C., Landon, O. A., Ribau, Z. J., Vallis, L. A., Darlington, G., Duncan, A. M., Haines, J., Ma, D. W. L., & Buchholz, A. C. (2025). Plant-based dietary index scores are not associated with body composition in young children. Canadian Journal of Dietetic Practice and Research, 86(3), 127-133. https://doi.org/10.3148/cjdpr-2025-006

Lichtenstein, A. H., Khera, A., Anderson, C. A. M., Appel, L. J., DeSilva, D. M., Gardner, C., Hu, F. B., Jones, D. W., Petersen, K. S., & American Heart Association. (2026). 2026 dietary guidance to improve cardiovascular health: A scientific statement from the American Heart Association. Circulation, 153(18), e1285-e1295. https://doi.org/10.1161/CIR.0000000000001435

Liebman, S. E., Baran, A., Barnett, T. D., Campbell, T. M., Chen, L., Friedman, S. M., Hasan, S., Le, T. H., Monk, R. D., Sabescumar, J., Wixom, N., Zhang, A., & Campbell, E. K. (2025). The effects of a whole-food plant-based nutrition education program on blood pressure and potassium in chronic kidney disease: A proof-of-concept study. Nutrients, 17(5), Article 779. https://doi.org/10.3390/nu17050779

López-Moreno, M., Rossi, E. V., López-Gil, J. F., Marrero-Fernández, P., Roldán-Ruiz, A., & Bertotti, G. (2025). Are plant-based diets detrimental to muscular strength? A systematic review and meta-analysis of randomized controlled trials. Sports Medicine - Open, 11, Article 62. https://doi.org/10.1186/s40798-025-00852-7

Macknin, M., Stegmeier, N., Thomas, A., Worley, S., Li, L., Hazen, S. L., & Tang, W. H. W. (2021). Three healthy eating patterns and cardiovascular disease risk markers in 9 to 18 year olds with body mass index >95%: A randomized trial. Clinical Pediatrics, 60(11-12), 474-484. https://doi.org/10.1177/00099228211044841

Miki, A. J., Livingston, K. A., Karlsen, M. C., Folta, S. C., & McKeown, N. M. (2020). Using evidence mapping to examine motivations for following plant-based diets. Current Developments in Nutrition, 4(3), Article nzaa013. https://doi.org/10.1093/cdn/nzaa013

Mo, Q., Wu, J., Lu, Y., & Zhang, X. (2025). Plant-based diets and total and cause-specific mortality: A meta-analysis of prospective studies. Frontiers in Nutrition, 12, Article 1518519. https://doi.org/10.3389/fnut.2025.1518519

Murciano, A., Malavolti, M., Fairweather-Tait, S., Paduano, S., Vinceti, M., & Filippini, T. (2025). Plant-based diets and risk of type 2 diabetes: Systematic review and dose-response meta-analysis. British Journal of Nutrition, 134(4), 277-296. https://doi.org/10.1017/S0007114525104157

Musicus, A. A., Wang, D. D., Janiszewski, M., Eshel, G., Blondin, S. A., Willett, W., & Stampfer, M. J. (2022). Health and environmental impacts of plant-rich dietary patterns: A US prospective cohort study. The Lancet Planetary Health, 6(11), e892-e900. https://doi.org/10.1016/S2542-5196(22)00243-1

National Institutes of Health, Office of Dietary Supplements. (2025, July 2). Vitamin B12: Fact sheet for health professionals. ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

Ostfeld, R. J. (2017). Definition of a plant-based diet and overview of this special issue. Journal of Geriatric Cardiology, 14(5), 315. https://doi.org/10.11909/j.issn.1671-5411.2017.05.008. Full text: pmc.ncbi.nlm.nih.gov/articles/PMC5466934/

Raj, S., Guest, N. S., Landry, M. J., Mangels, A. R., Pawlak, R., & Rozga, M. (2026). Vegetarian dietary patterns for adults: A position paper of the Academy of Nutrition and Dietetics. Journal of the Academy of Nutrition and Dietetics, 126(3), Article 156227. https://doi.org/10.1016/j.jand.2025.156227 (Original work published 2025)

Raygoza, C., Roberts, A., Guidetti, A., Cai, O., Sangowdar, P., Muriuki, E. N., Laverick-Johnson, H., Sanguinetti, G., Smith, E., Fammartino, A., Robinson, J., Lee, E., Policastro, P., Mills, C., Kuhnle, G., Svennevik, E., & Gardner, C. (2026). Plant-based vs. omnivore diets for athletic performance outcomes among recreational athletes in university dining halls: A randomized crossover study. Nutrition Journal, 25, Article 42. https://doi.org/10.1186/s12937-026-01290-1

Rieth, K. K. S., Campbell, E., Peppone, L. J., Netherby-Winslow, C., Culakova, E., McGuire, J., Sun, H., & Campbell, T. (2025). Effect of a whole food plant-based dietary intervention on cancer progression and inflammatory markers. The Oncologist, 30(10), Article oyaf294. https://doi.org/10.1093/oncolo/oyaf294

Satija, A., Bhupathiraju, S. N., Rimm, E. B., Spiegelman, D., Chiuve, S. E., Borgi, L., Willett, W. C., Manson, J. E., Sun, Q., & Hu, F. B. (2016). Plant-based dietary patterns and incidence of type 2 diabetes in US men and women: Results from three prospective cohort studies. PLOS Medicine, 13(6), Article e1002039. https://doi.org/10.1371/journal.pmed.1002039

Satija, A., Bhupathiraju, S. N., Spiegelman, D., Chiuve, S. E., Manson, J. E., Willett, W., Rexrode, K. M., Rimm, E. B., & Hu, F. B. (2017). Healthful and unhealthful plant-based diets and the risk of coronary heart disease in U.S. adults. Journal of the American College of Cardiology, 70(4), 411-422. https://doi.org/10.1016/j.jacc.2017.05.047

Satija, A., Malik, V., Rimm, E. B., Sacks, F., Willett, W., & Hu, F. B. (2019). Changes in intake of plant-based diets and weight change: Results from 3 prospective cohort studies. The American Journal of Clinical Nutrition, 110(3), 574-582. https://doi.org/10.1093/ajcn/nqz049

Springmann, M., Clark, M. A., Rayner, M., Scarborough, P., & Webb, P. (2021). The global and regional costs of healthy and sustainable dietary patterns: A modelling study. The Lancet Planetary Health, 5(11), e797-e807. https://doi.org/10.1016/S2542-5196(21)00251-5

Storz, M. A. (2022). What makes a plant-based diet? A review of current concepts and proposal for a standardized plant-based dietary intervention checklist. European Journal of Clinical Nutrition, 76(6), 789-800. https://doi.org/10.1038/s41430-021-01023-z

Tessier, A.-J., Wang, F., Korat, A. A., Eliassen, A. H., Chavarro, J., Grodstein, F., Li, J., Liang, L., Willett, W. C., Sun, Q., Stampfer, M. J., Hu, F. B., & Guasch-Ferré, M. (2025). Optimal dietary patterns for healthy aging. Nature Medicine, 31(5), 1644-1652. https://doi.org/10.1038/s41591-025-03570-5

Thompson, A. S., Tresserra-Rimbau, A., Karavasiloglou, N., Jennings, A., Cantwell, M., Hill, C., Perez-Cornago, A., Bondonno, N. P., Murphy, N., Rohrmann, S., Cassidy, A., & Kühn, T. (2023). Association of healthful plant-based diet adherence with risk of mortality and major chronic diseases among adults in the UK. JAMA Network Open, 6(3), Article e234714. https://doi.org/10.1001/jamanetworkopen.2023.4714

Tuso, P. J., Ismail, M. H., Ha, B. P., & Bartolotto, C. (2013). Nutritional update for physicians: Plant-based diets. The Permanente Journal, 17(2), 61-66. https://doi.org/10.7812/TPP/12-085

Wagenaar, C. A., Walrabenstein, W., van der Leeden, M., Turkstra, F., Gerritsen, M., Twisk, J. W. R., Boers, M., van der Esch, M., van Middendorp, H., Weijs, P. J. M., & van Schaardenburg, D. (2024). Long-term effectiveness of a lifestyle intervention for rheumatoid arthritis and osteoarthritis: 1-year follow-up of the "Plants for Joints" randomised clinical trial. RMD Open, 10(1), Article e004025. https://doi.org/10.1136/rmdopen-2023-004025

Walrabenstein, W., Wagenaar, C. A., van der Leeden, M., Turkstra, F., Twisk, J. W. R., Boers, M., van Middendorp, H., Weijs, P. J. M., & van Schaardenburg, D. (2023). A multidisciplinary lifestyle program for rheumatoid arthritis: The "Plants for Joints" randomized controlled trial. Rheumatology, 62(8), 2683-2691. https://doi.org/10.1093/rheumatology/keac693

Wang, Y., Liu, B., Han, H., Hu, Y., Zhu, L., Rimm, E. B., Hu, F. B., & Sun, Q. (2023). Associations between plant-based dietary patterns and risks of type 2 diabetes, cardiovascular disease, cancer, and mortality: A systematic review and meta-analysis. Nutrition Journal, 22, Article 46. https://doi.org/10.1186/s12937-023-00877-2

Weston, L. J., Kim, H., Talegawkar, S. A., Tucker, K. L., Correa, A., & Rebholz, C. M. (2022). Plant-based diets and incident cardiovascular disease and all-cause mortality in African Americans: A cohort study. PLOS Medicine, 19(1), Article e1003863. https://doi.org/10.1371/journal.pmed.1003863

Wright, N., Wilson, L., Smith, M., Duncan, B., & McHugh, P. (2017). The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes. Nutrition & Diabetes, 7(3), Article e256. https://doi.org/10.1038/nutd.2017.3

Evidence rating and review record

Each row identifies the method, source, outcome or recommendation, and comparison being rated. Ratings from different tools are not interchangeable. The source is either a named published review or this page's own judgment. The rating in the banner is for this diet's main claimed outcome or recommendation, and the banner names the tool that produced it. A high rating means the research is solid; it does not mean the diet is right for everyone, and it does not mean a coach should recommend it.

Every rated row on this page was rated with GRADE, which uses the same 4-level scale as the clinical guidelines you will meet in practice. High means further research is very unlikely to change the conclusion. Moderate means further research may change it. Low means further research is likely to change it. Very low means the conclusion is uncertain. GRADE rates each outcome separately, so a diet can be high for one outcome and very low for another.

Two things about this table matter before reading it. Most rows rate associations between diet scores and disease in cohort studies, and those labels describe how sure we can be that the association is real, not that following the diet causes the outcome; they do not transfer to a strict whole-food plant-based diet, which few people in those cohorts ate. And the trial rows rate programs that combined the diet with other changes. Ratings marked as this page's own judgment were assigned from the evidence given in each row's reasons; ratings from a published review are reported exactly as that review published them.

On a narrow screen, scroll the table sideways to see every column.

Evidence ratings, their sources and reasons

Outcome	Certainty	Who rated it, and for which comparison	Why it is rated this way
Type 2 diabetes, healthful plant-based diet index (the banner)	Low, for an association	This page's own judgment, using GRADE. Highest against lowest healthful index scores in adults in prospective cohorts: 11 cohort studies pooled, relative risk 0.75, from 0.69 to 0.82 (Murciano et al., 2025), with the Harvard cohorts' 0.66, from 0.61 to 0.72 (Satija et al., 2016); follow-up 2 to more than 20 years. The 2023 Harvard meta-analysis totals are not used, because they combine different kinds of comparison (Wang et al., 2023)	Cohort studies start low. Risk of bias: not lowered beyond that starting point; the review judged none of the 11 healthful-index studies at high risk of bias, and confounding by other healthy habits is the reason cohort evidence starts low. Inconsistency: not lowered; heterogeneity was substantial (I-squared 73 percent), but every estimate pointed the same way, so the variation is in the size of the association, not its direction, and the rating is for direction only. Indirectness: not lowered for the question as stated, the association of a diet score, though it does not transfer to following a strict whole-food plant-based diet. Imprecision: not lowered (0.69 to 0.82). Publication bias: not detected in this review; a signal in a broader pool in another review (Wang et al., 2023) is not evidence of bias in this subset, so it is not counted. Not raised for the dose-response pattern, because confounding by other healthy habits could produce a gradient.
Type 2 diabetes, unhealthful plant-based diet index	Very low, for an association	This page's own judgment, using GRADE. Highest against lowest unhealthful index scores in adults in prospective cohorts: 7 studies pooled, 1.27, from 1.00 to 1.60 (Murciano et al., 2025); the Harvard cohorts, 1.16, from 1.08 to 1.25 (Satija et al., 2016)	Cohort studies start low. Risk of bias: not lowered beyond that starting point; the review judged none of these studies at high risk of bias. Inconsistency: lowered 1 level; the 7 study results in the 2025 pool varied far more than chance would explain (I-squared 91 percent), the review did not explain the variation, and that pool left out the 3 Harvard cohorts that first reported the association. Indirectness: not lowered for the association question. Imprecision: serious as well, because the pooled interval reaches no difference, but the rating is already at the lowest level. Publication bias: not detected in the review.
Coronary heart disease, healthful plant-based diet index	Low, for an association	This page's own judgment, using GRADE. Highest against lowest healthful index scores in adults in prospective cohorts: Harvard cohorts, highest against lowest tenth, 0.75, from 0.68 to 0.83, follow-up up to 28 years (Satija et al., 2017); UK Biobank heart attacks, highest against lowest quarter, 0.86, from 0.78 to 0.95 (Thompson et al., 2023)	Cohort studies start low. Risk of bias: not lowered beyond that starting point; both are large prospective cohorts that adjusted for the main confounders, and confounding by other healthy habits is the reason cohort evidence starts low. Inconsistency: not lowered; both point the same way. The Jackson Heart Study's analysis of coronary heart disease, with 173 cases, is too imprecise to support or contradict them (Weston et al., 2022). Indirectness: not lowered for the association question. Imprecision: not lowered; both intervals exclude no difference. Publication bias: not assessable from these studies. Not raised.
Any cardiovascular disease, healthful plant-based diet index	Low, for an association	This page's own judgment, using GRADE. Highest against lowest healthful index scores in adults in prospective cohorts: 10 cohort estimates pooled, 0.85, from 0.80 to 0.92 (Wang et al., 2023). The pool includes a U.S. community cohort, 0.91, from 0.82 to 1.01 (Kim, Caulfield, Garcia-Larsen, Steffen, Coresh, & Rebholz, 2019), and an African American cohort, 1.07, from 0.80 to 1.42 in its own report (Weston et al., 2022)	Cohort studies start low. Risk of bias: not lowered beyond that starting point, for the reason given above. Inconsistency: not lowered; heterogeneity was moderate to substantial (I-squared 62 percent), but most estimates fell below 1, and the community cohort's weaker estimate is not clearly different. The African American cohort's estimates are too imprecise to support or contradict the others, the rule this table applies to that cohort in every row. Indirectness: not lowered for the association question. Imprecision: not lowered (0.80 to 0.92). Publication bias: not assessable separately for this index. Not raised.
Coronary heart disease, unhealthful plant-based diet index	Low, for an association	This page's own judgment, using GRADE. Highest against lowest unhealthful index scores in adults in prospective cohorts: Harvard cohorts, highest against lowest tenth, 1.32, from 1.20 to 1.46 (Satija et al., 2017); UK Biobank heart attacks, highest against lowest quarter, 1.17, from 1.06 to 1.29 (Thompson et al., 2023)	Cohort studies start low. Risk of bias: not lowered beyond that starting point, for the reason given above. Inconsistency: not lowered; the size of the association differed between the 3 Harvard cohorts and UK Biobank, but all pointed the same way. The Jackson Heart Study's analysis of coronary heart disease, with 173 cases, is too imprecise to support or contradict them. Indirectness: not lowered for the association question. Imprecision: not lowered; both intervals exclude no difference. Publication bias: not assessable from these studies. Not raised. The rating is for direction only.
Any cardiovascular disease, unhealthful plant-based diet index	Very low, for an association	This page's own judgment, using GRADE. Highest against lowest unhealthful index scores in adults in prospective cohorts: higher in UK Biobank (Thompson et al., 2023); no association in a U.S. community cohort, 0.94, from 0.85 to 1.04 (Kim, Caulfield, Garcia-Larsen, Steffen, Coresh, & Rebholz, 2019), or in an African American cohort, 0.95, from 0.71 to 1.28 (Weston et al., 2022). The 2023 Harvard pooled figure is not used, because it counts some of the same people twice	Cohort studies start low. Risk of bias: not lowered beyond that starting point, for the reason given above. Inconsistency: lowered 1 level; UK Biobank found a higher rate, while the U.S. community cohort found no association with a fairly narrow interval, which rules out more than a small increase, and the difference is not explained. The African American cohort's estimate is too imprecise to support or contradict either. Indirectness: not lowered for the association question. Imprecision: not lowered on its own; the community cohort's interval is narrow, and the uncertainty lies between cohorts rather than within them. Publication bias: not assessable. UK Biobank's text gives an interval that does not contain its own estimate, so its number is not given here.
Death from any cause, healthful plant-based diet index	Low, for an association	This page's own judgment, using GRADE. Highest against lowest healthful index scores in adults in prospective cohorts: 13 datasets from 11 cohort studies, 0.86, from 0.81 to 0.92 (Mo et al., 2025); each 10-point increase over 12 years, 0.90 (Baden et al., 2019); in a national U.S. survey cohort, 0.95 per 10 points above the median score (Kim et al., 2018)	Cohort studies start low. Risk of bias: not lowered beyond that starting point; the review scored its studies 7 to 9 on the Newcastle-Ottawa Scale, median 8. Inconsistency: not lowered; heterogeneity was high in the review's subgroup analyses (I-squared 95 percent for the studies from the Americas), so the size of the pooled figure is uncertain, but the estimates pointed the same way, including the national survey cohort's lower death rates with higher healthful scores above the median. Indirectness: not lowered for the association question. Imprecision: not lowered (0.81 to 0.92). Publication bias: not detected by the review's Begg and Egger tests. Not raised. The rating is for direction, not for a uniform percentage reduction.
Breast cancer, healthful plant-based diet index, per 10-point increase	Published as Moderate; not independently confirmed	Gil-Lespinard et al., 2026, using GRADE. Healthful index, per 10-point increase, 5 cohort estimates, hazard ratio 0.94, from 0.93 to 0.96	Carried as the review published it. The review's supplementary table lists risk of bias as serious and inconsistency, indirectness and imprecision as not serious, with publication bias undetected, while noting that it could not be reliably assessed with so few studies. The review disagrees with itself in 3 ways: its main text says ratings started at moderate and its supplement says they started at low; its GRADE table gives heterogeneity as I-squared 20.4 percent and its sensitivity table as 79.4 percent; and the sensitivity table gives a different interval, 0.92 to 0.97. These discrepancies prevent this page from independently confirming the label, and this page does not substitute a rating of its own.
Colorectal cancer, healthful plant-based diet index, per 10-point increase	Published as Low; not independently confirmed	Gil-Lespinard et al., 2026, using GRADE. Healthful index, per 10-point increase, 5 cohort estimates, 2 of them the men and the women of one cohort, hazard ratio 0.95, from 0.92 to 0.98	Carried as the review published it. The review's supplementary table lists risk of bias and inconsistency as serious, with indirectness and imprecision not serious and publication bias undetected. The same starting-level discrepancy applies, and heterogeneity is given as I-squared 55.2 percent in the GRADE table and 62.1 percent in the sensitivity table. These discrepancies prevent this page from independently confirming the label.
HbA1c at 24 weeks to 6 months, whole-food plant-based programs against usual or standard care	Low	This page's own judgment, using GRADE. Question: does a whole-food plant-based program, as delivered, lower HbA1c more than usual or standard care? Adults with type 2 diabetes in the Marshall Islands, 169 randomized, 136 analyzed, 8 mmol/mol lower at 24 weeks, from 1 to 14 (Hanick et al., 2025); adults with overweight and a cardiometabolic condition in New Zealand, 65 randomized, 49 at 6 months, 5 mmol/mol lower, from 2 to 8 (Wright et al., 2017)	Randomized trials start high. Risk of bias: lowered 1 level; neither trial could be blinded, one kept no diet records and lost 31 people before baseline, and the other lost a quarter of its participants. Inconsistency: not lowered; both favored the program and their intervals overlap. Indirectness: not lowered; the question is about the programs as delivered, so their other parts are part of what is rated, though the result cannot be credited to the diet alone. Imprecision: lowered 1 level; this page treats a difference of about 5 mmol/mol (0.5 percentage points) as clearly meaningful, and both intervals include smaller differences. Publication bias: not assessable with 2 trials.
Body weight, as measured, at 16 weeks to 6 months, whole-food plant-based programs against usual or standard care	Low	This page's own judgment, using GRADE. Question: how much more weight do people lose in a whole-food plant-based program, as delivered, than with usual or standard care? 2.7 kilograms lower at 24 weeks, from 1.8 to 3.6 (Hanick et al., 2025); 3.9 kilograms lower at 16 weeks, from 2.6 to 5.2 (Walrabenstein et al., 2023); 10.6 kilograms lower at 6 months, from 7.7 to 13.5 (Wright et al., 2017)	Randomized trials start high. Risk of bias: lowered 1 level (unblinded, losses to follow-up). Inconsistency: lowered 1 level; the 3 results differ by much more than chance, the BROAD interval does not overlap the other 2, and the differences in population and program that might explain this were not tested. Indirectness: not lowered; the question is about the programs as delivered. Imprecision: not lowered; each interval is narrow compared with the differences between trials, so the uncertainty lies between the trials rather than within them. This page sets no threshold for a meaningful weight difference, because it does not treat weight as a goal. Publication bias: not assessable with 3 trials. Reported as a measurement, not as a goal.
LDL cholesterol at 4 weeks, adults with inherited high cholesterol not taking cholesterol medicine, provided whole-food plant-based diet against a typical North American diet	High	This page's own judgment, using GRADE. 1 randomized crossover feeding trial, 51 randomized and 50 analyzed, 1.28 mmol/L lower, from 1.02 to 1.55, about 50 mg/dL, from 39 to 60 (Lessard-Lord et al., 2026)	Randomized trials start high. Risk of bias: not lowered; all food was provided, the crossover design compares each person with themselves, and only 1 person dropped out. Inconsistency: not applicable to a single trial. Indirectness: not lowered for the question as stated, which is narrow. Imprecision: not lowered; this page treats a reduction of 0.5 mmol/L (about 19 mg/dL) as clearly meaningful, because in statin trials a further reduction of about that size went with 15 percent fewer major vascular events (Cholesterol Treatment Trialists' Collaboration, 2010), and the whole interval lies well beyond it; the trial also reached its planned total of 50 completers. Publication bias: not assessable for 1 trial. High applies only to this question: this diet included about 18 percent of energy from animal foods, and the result does not transfer to strict vegan versions, other people, longer periods, people still taking cholesterol medicine, or heart attacks and strokes.
Heart attack, stroke, cancer or death, in trials	Not rated	This page's own judgment. No comparison is possible	The searches for this page found no randomized trial of a whole-food plant-based diet that measured these outcomes. This is a statement about the trials of whole-food plant-based programs found for this page, not a finding of no effect, and it does not cover trials of the Ornish program or of vegan diets.
Rheumatoid arthritis disease activity	Not rated as an effect of the diet	This page's own judgment. Walrabenstein et al., 2023: a 16-week program of diet, physical activity, and stress and sleep coaching against usual care, 83 randomized	The diet was one part of a multicomponent program in a single trial, so the result cannot be attributed to the diet. The trial's own finding is reported in section 4.

How this archive talks about weight. This page reports what studies measured, including body weight, and does not treat weight change as a goal or as a measure of a diet's success. Weight a person loses without meaning to can be a sign of a health problem, and where it is, the page names it as a reason to see a clinician. People are described the way the study described them.

Last reviewed: Reviewed and approved by James Peth, MS, MPH, PhD, on October 6, 2026, after a combined final review of the third batch of 5 archive pages, the plant-based family, the repairs it asked for and a focused recheck. Written October 4, 2026. Several studies cited here could be read only as abstracts, and the page says so where each is used.

What changed after the combined final review: The review was completed October 4, 2026, and the page was revised the same day. Three trials missed in the first version were added: a 1-year trial in children and their parents, a counseling trial in older adults with mild cognitive impairment, and a 15-day pilot in adults with kidney disease; the statements about missing evidence were narrowed to match. Pooled figures that combined different kinds of comparison, or counted the same people twice, were removed.

The calcium result from the modeled menus, the national survey mortality result, and the low blood sugar steps in section 6 were corrected. The heart disease and cardiovascular disease ratings were split into separate rows; for the unhealthful index, coronary heart disease is rated Low and any cardiovascular disease stays Very low, because only the second has results that genuinely disagree. The reasons for the HbA1c, body weight and LDL cholesterol ratings were rewritten, and the LDL cholesterol rating changed from Moderate to High after the review found no valid reason to lower it. The 2 published cancer ratings are now marked as not independently confirmed. The Academy of Nutrition and Dietetics position is cited in its corrected 2026 version, and several references were corrected.

What changed after the focused recheck: The focused recheck was completed October 5, 2026, and passed every repair except the description of the kidney disease pilot. That description was corrected on October 6, 2026: 43 people were randomized and 40 analyzed, the trial excluded only substantial protein in the urine, and the blood pressure result is a difference in change between the groups. No rating changed.

Updated October 21, 2026: The American Heart Association is now named as an author of its 2026 dietary guidance statement (Lichtenstein et al., 2026), as the publisher's citation credits it. No content changed.

Next scheduled review: August 2027. Pages built on annual guidance are rechecked each year. The American College of Lifestyle Medicine's position and the federal vitamin B12 fact sheet are updated from time to time and should be rechecked first.

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Diet Reference Archive | One James

Prepared by James Peth, MS, MPH, PhD

© 2026–2027 One James. All rights reserved.

This page is for education and coaching practice. It is not medical or dietary advice.