42 studies, limitations attached
The evidence behind LP3
No trial has tested the LP3 Diet as a whole. What follows are the studies behind the parts it is assembled from — the plant base, the protein target, the seafood, and the foods it leaves out — together with the dietary patterns closest to LP3 that have been tested. Cohort studies show association, not cause; where a finding comes from a randomized trial, that is said plainly.
Forty-two studies sit behind LP3. Most of them test a part of the diet rather than the whole of it, and most are cohort studies, which show association rather than cause. Where a study has a weakness — an observational design, a food-frequency questionnaire, a weak credibility rating, high heterogeneity — it is named next to the finding rather than left for you to come across. The page runs in that order: the patterns closest to LP3 that have actually been tested, then the evidence behind each part of the plate, then the findings that do not support LP3, under their own heading.
What it does for your heart
LP3 was built for body composition. The cardiovascular evidence came with it, because a plant base with fish on top is the pattern the heart literature keeps arriving at independently.
Fiber, at the level a plant base actually delivers
Pooling prospective cohorts, each additional 10 g of daily fiber was associated with roughly 9% lower cardiovascular mortality. In people who already have heart disease, higher fiber intake was associated with lower all-cause mortality.
fiber and cardiovascular mortality · fiber in existing heart disease
The plant base is a recognized cholesterol-lowering pattern
Nuts, legumes and viscous fiber — the foundation of an LP3 plate — are the core of the Portfolio dietary pattern, which lowered LDL cholesterol by about 17% in free-living trials and by roughly 27% alongside a low-saturated-fat diet.
Fat, from the right places
In a randomized trial of 7,447 adults at high cardiovascular risk, a Mediterranean pattern supplemented with extra virgin olive oil or with mixed nuts cut the risk of heart attack, stroke or cardiovascular death by around 30% compared with the control arm — which had been advised to eat less fat. Within that study, each 10 g/day more extra virgin olive oil was associated with 10% lower cardiovascular risk.
Seafood instead of red meat, which counts twice
An umbrella review found each 100 g/day increment in fish intake associated with lower cardiovascular mortality, coronary heart disease, myocardial infarction and stroke. Meanwhile 50 g/day more processed meat was associated with 18% higher ischemic heart disease risk, and unprocessed red meat 9% higher, with no such association for fish.
fish and chronic disease · red meat and heart disease · meat, poultry and fish compared
Leaving the ultra-processed aisle alone
In a randomized inpatient trial where diets were matched for calories, sugar, fat, sodium and fiber, people still ate about 500 more calories a day on the ultra-processed one — gaining weight on it and losing weight on the unprocessed diet.
Most of these studies tested the parts LP3 is built from rather than LP3 itself, and most are cohort studies showing association rather than cause. The closest anyone has come to testing this shape of plate is the pescatarian group in the Adventist Health Study, which had the lowest mortality of any diet group in 73,308 adults — narrowly, with the vegans close enough behind that the study cannot separate them. All 42 are listed below, including the section where the evidence cuts against LP3.
6 studies
Has anything like this been tested?
No trial has tested LP3 itself. But LP3 is less a new idea than a particular combination of old ones, and the patterns closest to it have been studied for decades — some in large cohorts, some in randomized trials where every meal was provided. This is the closest the literature comes to the plate this book describes.
Vegetarian Dietary Patterns and Mortality in Adventist Health Study 2 (Orlich et al., JAMA Internal Medicine, 2013)
73,308 adults. Compared with non-vegetarians, pesco-vegetarians — people who ate plants plus fish — had the lowest all-cause mortality of any group studied, HR 0.81 (95% CI 0.69–0.94). Vegans came in at 0.85 (0.73–1.01), lacto-ovo vegetarians at 0.91 (0.82–1.00). Of everything on this page, that is the closest anyone has come to testing the LP3 plate. It came out lowest, though the vegans' interval overlaps it almost entirely, so the study cannot rank the two. Observational; a mean follow-up of 5.8 years is short for a mortality study; and the cohort is Adventist, so its members also smoke and drink far less than average.
Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up (Tong et al., BMJ, 2019)
48,188 adults in EPIC-Oxford, followed 18 years. Fish eaters had 13% less ischemic heart disease than meat eaters, HR 0.87 (0.77–0.99). Vegetarians had 22% less, HR 0.78 (0.70–0.87) — and also 20% more total stroke, HR 1.20 (1.02–1.40), about three extra cases per 1,000 people over ten years, mostly hemorrhagic. Fish eaters showed no such stroke signal. Both halves of that result are printed here because together they are the plainest argument for why LP3 keeps the seafood instead of going the rest of the way to plant-only. Observational, and the stroke finding comes from one cohort and has not been consistently replicated elsewhere.
A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure (Appel et al., New England Journal of Medicine, 1997)
The original DASH trial. 459 adults, eight weeks, every meal supplied. The combination diet — built on fruit, vegetables and whole grains, with lean meat, poultry and fish on top and saturated fat cut — lowered blood pressure by 11.4/5.5 mmHg in participants who had hypertension and 3.5/2.1 mmHg in those who did not. Calories and sodium were held identical across all three diets, so the pattern did the work and not weight loss. This is the closest randomized trial to LP3's shape. The difference worth naming: DASH keeps low-fat dairy, and LP3 does not.
Effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile and inflammation markers in metabolic syndrome — SYSDIET (Uusitupa et al., Journal of Internal Medicine, 2013)
200 adults with metabolic syndrome, 18 to 24 weeks. A plant-forward pattern including three fish meals a week lowered non-HDL cholesterol by 0.18 mmol/L (P = 0.04) and the LDL/HDL ratio by 0.15 (P = 0.046) against the control diet. Participants were instructed to hold their weight steady and anyone whose weight moved more than 4 kg was excluded — so, as in DASH, the lipid change came from what was eaten rather than from getting smaller. Modest effect sizes, and a high dropout rate in the control arm.
Low-Calorie Vegetarian Versus Mediterranean Diets for Reducing Body Weight and Improving Cardiovascular Risk Profile — CARDIVEG (Sofi et al., Circulation, 2018)
118 adults ran a low-calorie vegetarian diet and a low-calorie Mediterranean diet for three months each, in crossover, so each person served as their own comparison. Both lost about 1.8 kg and both cut fat mass, with no meaningful difference between them. The vegetarian phase lowered LDL further; the Mediterranean phase lowered triglycerides further. It matters to LP3 because it shows the two approaches are not rivals — they reached much the same place by different routes, which is the premise of putting fish on a plant base. Mostly women, mean age 51, and three months is short.
Cardiovascular health and cancer risk associated with plant based diets: an umbrella review (Capodici et al., PLOS ONE, 2024)
48 reviews and meta-analyses pooled. Vegetarians had lower cardiovascular disease overall, RR 0.85 (0.79–0.92), and lower ischemic heart disease, RR 0.79 (0.71–0.88). Included here with the caveat that matters most: the authors deliberately excluded pesco- and pollo-vegetarian diets from their definition, which means they excluded the pattern LP3 most resembles. It supports the plant base. It does not test the plate. The authors also flag high heterogeneity and average review quality.
17 studies
Heart and circulation
Fiber intake, the cholesterol-lowering plant foods at the base of the plate, seafood in place of red meat, and the removal of ultra-processed food.
Show 17 studiesHide these
17 studies
Heart and circulation
Fiber intake, the cholesterol-lowering plant foods at the base of the plate, seafood in place of red meat, and the removal of ultra-processed food.
Dietary fibre intake and mortality from cardiovascular disease and all cancers
Dose-response meta-analysis of prospective cohorts. Each 10 g/day increment in fiber intake was associated with about 9% lower cardiovascular mortality.
Dietary fibre in hypertension and cardiovascular disease management (Reynolds et al., BMC Medicine, 2022)
Systematic review and meta-analyses. In adults who already have cardiovascular disease, higher fiber intake was associated with reduced all-cause mortality on moderate-certainty evidence.
Portfolio Dietary Pattern and Cardiovascular Disease (Chiavaroli et al., Progress in Cardiovascular Diseases, 2018)
Meta-analysis of controlled trials of a plant-based pattern built on nuts, plant protein and viscous fiber. It produced clinically meaningful improvements in LDL cholesterol, other cardiometabolic risk factors, and estimated 10-year coronary risk.
Relationship Between a Plant-Based Dietary Portfolio and Risk of Cardiovascular Disease (Journal of the American Heart Association, 2021)
Reports that the pattern lowered LDL cholesterol by 17% in free-living trials, and by 27% when combined with a low-saturated-fat diet.
Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial (Ornish et al., Lancet, 1990)
Randomized trial in 48 patients with coronary disease, followed by quantitative angiography. Average percent diameter stenosis regressed from 40.0% to 37.8% in the experimental group at one year while it progressed in controls, and LDL fell 37% without cholesterol-lowering drugs. The trial diet ran near 10% of calories from fat and permitted no animal products except egg white and one cup a day of nonfat milk or yogurt — the same two exceptions LP3 makes. Note that diet was bundled with exercise, stress management, smoking cessation and group support, so the diet was never isolated, and regression tracked adherence to the whole program.
Intensive Lifestyle Changes for Reversal of Coronary Heart Disease (Ornish et al., JAMA, 1998)
Five-year follow-up of the Lifestyle Heart Trial. The gap between groups widened rather than closed, with more than twice as many cardiac events in the control group. Small sample: 28 experimental, 20 control.
Oats, beta-glucan and coronary heart disease (21 CFR 101.81)
The FDA-authorized health claim, in force since 1997 and extended to barley in 2005. Soluble fiber from whole oats, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease, at 3 g/day of beta-glucan. The condition on that claim is the diet LP3 describes.
Updating a 12-year experience with arrest and reversal therapy for coronary heart disease (Esselstyn, Am J Cardiol, 1999)
Twenty-four adults with coronary disease on a plant-based diet under 10% of calories from fat, with no added oil — though skim milk and no-fat yogurt were permitted, the same narrow dairy exception LP3 makes. Among adherent patients, angiography showed arrest of disease, with no coronary events over 12 years against 49 events in the 8 years before. Read the limits with the result: there was no control group, the participants were self-selected volunteers, and the earlier cohort also took cholesterol-lowering medication, so diet was never isolated.
A way to reverse CAD? (Esselstyn, Gendy, Doyle, Golubic, Roizen, J Fam Pract, 2014)
198 consecutive patients with cardiovascular disease counselled onto plant-based nutrition; 177 (89%) were adherent over a mean of 3.7 years, with a recurrent major cardiac event rate of 0.6% among them against adverse events in 13 of 21 non-adherent participants. Again: no control arm, and volunteers who chose to take part. LP3 borrows the exclusion logic from this work; it is not this protocol and does not claim these outcomes.
Benefits of the Mediterranean Diet: insights from the PREDIMED study
Randomized trial in 7,447 adults at high cardiovascular risk. A Mediterranean diet supplemented with extra virgin olive oil or with mixed nuts produced a hazard ratio of 0.70 for heart attack, stroke or cardiovascular death versus the control arm, which was advised to follow a low-fat diet. Note that PREDIMED was retracted and republished in 2018 after randomization irregularities; the republished analysis reached the same conclusion.
PREDIMED Study Retraction and Republication (Harvard T.H. Chan School of Public Health)
A plain-English account of why PREDIMED was withdrawn and republished, and what did and did not change. Linked here so the caveat is not buried.
Olive oil intake and risk of cardiovascular disease and mortality in the PREDIMED Study
Each 10 g/day increase in extra virgin olive oil intake was associated with 10% lower cardiovascular disease risk and 7% lower cardiovascular mortality. Common olive oil showed weaker associations than extra virgin.
Fish Consumption and the Risk of Chronic Disease: an umbrella review of meta-analyses of prospective cohort studies
Moderate-quality evidence that each 100 g/day increment in fish intake was associated with lower all-cause mortality, cardiovascular mortality, coronary heart disease, myocardial infarction, stroke and heart failure.
Intake of Fish and Marine n-3 PUFAs and Risk of Cardiovascular Disease Mortality (Jiang et al., Nutrients, 2021)
25 cohorts, over 2 million participants. Fish intake was inversely associated with cardiovascular mortality; each 20 g/day increment corresponded to about 4% lower risk.
Meat consumption and risk of ischemic heart disease: a systematic review and meta-analysis
Over 1.4 million adults. 50 g/day more processed meat was associated with 18% higher ischemic heart disease risk and unprocessed red meat with 9% higher. No association was found for poultry.
Associations of Processed Meat, Unprocessed Red Meat, Poultry, or Fish Intake With Incident Cardiovascular Disease and All-Cause Mortality (JAMA Internal Medicine, 2020)
Pooled analysis of 29,682 US adults across six cohorts. Processed meat, unprocessed red meat and poultry were each associated with incident cardiovascular disease; fish was not. Processed and red meat were associated with all-cause mortality; poultry and fish were not.
Long-Term Consumption of 10 Food Groups and Cardiovascular Mortality
Dose-response meta-analysis. Each 10 g/day of whole grains was associated with 4% lower cardiovascular mortality, while the highest category of red and processed meat intake carried higher risk.
4 studies
Fat loss and metabolic health
Trials of plant-predominant eating on body weight, fat mass and insulin sensitivity, plus the controlled trial on ultra-processed food and calorie intake.
Show 4 studiesHide these
4 studies
Fat loss and metabolic health
Trials of plant-predominant eating on body weight, fat mass and insulin sensitivity, plus the controlled trial on ultra-processed food and calorie intake.
Effect of a Low-Fat Vegan Diet on Body Weight, Insulin Sensitivity, Postprandial Metabolism, and Intramyocellular and Hepatocellular Lipid Levels (JAMA Network Open, 2020)
Randomized clinical trial. A plant-based intervention reduced body weight by lowering energy intake and raising postprandial metabolism, with reductions in liver and muscle fat and improved insulin sensitivity.
A Plant-Based High-Carbohydrate, Low-Fat Diet in Overweight Individuals in a 16-Week Randomized Clinical Trial (Nutrients, 2018)
Randomized trial in 75 overweight adults with DXA-measured body composition. Treatment effects were a 6.5 kg reduction in body weight and a 4.3 kg reduction in fat mass versus control.
Effects of Plant-Based Diets on Markers of Insulin Sensitivity: a systematic review and meta-analysis of randomised controlled trials
Eight randomized trials, 716 participants. Plant-based diets improved HOMA-IR and fasting insulin in people with overweight or obesity.
Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain (Hall et al., Cell Metabolism, 2019)
Randomized controlled inpatient trial, 20 adults, two weeks on each diet. With calories, sugar, fat, sodium, fiber and macronutrients matched, people ate about 500 kcal/day more on the ultra-processed diet, gaining 0.9 kg on it and losing 0.9 kg on the unprocessed one.
6 studies
Building muscle
How much protein is needed alongside resistance training, where that protein can come from, and how it should be spread across the day. This is the half of LP3 that plant-based eating is usually accused of failing at, so it is the half that needs the most evidence.
Show 6 studiesHide these
6 studies
Building muscle
How much protein is needed alongside resistance training, where that protein can come from, and how it should be spread across the day. This is the half of LP3 that plant-based eating is usually accused of failing at, so it is the half that needs the most evidence.
A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength (Morton et al., British Journal of Sports Medicine, 2018)
49 studies, 1,863 participants. Protein intake increased gains in strength and fat-free mass during resistance training, with no further gains in fat-free mass beyond roughly 1.62 g/kg/day.
Effect of Plant Versus Animal Protein on Muscle Mass, Strength, Physical Performance, and Sarcopenia (Reid-McCann et al., Nutrition Reviews, 2025)
30 randomized trials, 1,538 participants. Animal protein showed a small advantage over plant protein for muscle mass, with no significant difference for strength or physical performance. This is the reason LP3 layers animal protein onto a plant base rather than going fully plant-based.
High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations (Hevia-Larraín et al., Sports Medicine, 2021)
38 young men — 19 habitual vegans, 19 omnivores — through 12 weeks of supervised resistance training, with both groups brought to about 1.6 g of protein per kg per day. Muscle cross-sectional area rose 2.2 cm² in the vegans and 2.8 cm² in the omnivores; leg-press strength rose 97 kg and 117 kg. Neither gap was statistically significant, and the authors concluded that a high-protein, exclusively plant-based diet is “not different” from a protein-matched mixed diet for building muscle and strength. Small, young, male, and 12 weeks — but it is the most direct test there is of the fear that a plant-heavy plate costs you muscle.
Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss (Longland et al., American Journal of Clinical Nutrition, 2016)
40 young men, four weeks, a 40% calorie deficit and hard training. At 2.4 g of protein per kg per day they gained 1.2 kg of lean mass while losing 4.8 kg of fat. At 1.2 g/kg they gained 0.1 kg and lost 3.5 kg. Both numbers moving in the right direction at once, in a randomized trial — which is the thing LP3 claims is possible. Four weeks, young men training hard, and a protein dose above what this book asks for: it demonstrates the mechanism, not the dose.
Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults (Mamerow et al., Journal of Nutrition, 2014)
Eight healthy adults ate the same total protein either spread evenly across three meals (about 30 g each) or skewed toward dinner (11 g, 16 g, 63 g). The even pattern produced a 25% higher 24-hour muscle protein synthesis rate, 0.075%/h against 0.056%/h (P = 0.003). This is the study behind LP3's rule of putting protein at every meal rather than loading it into dinner. Eight people, and a synthesis rate measured across a single day rather than a muscle outcome measured across months.
Long-term effects of plant vs. animal protein supplementation on body composition, muscle strength, physical performance, and cardiometabolic risk factors (Yimam et al., Frontiers in Nutrition, 2026)
18 randomized trials, 1,893 participants. Plant and animal protein supplementation produced no significant difference in body composition, muscle strength, physical performance or cardiometabolic markers, so long as total protein intake was adequate. Read it as no evidence of a gap rather than proof there is none — the confidence intervals are wide enough to hide a real difference in either direction. It also sits against Reid-McCann above, which found a small advantage for animal protein on muscle mass. The honest reading of the two together is that source matters less than getting enough, which is what LP3 assumes.
1 study
The egg white rule
Why LP3 keeps the whites and drops the yolks.
Show 1 studiesHide these
1 study
The egg white rule
Why LP3 keeps the whites and drops the yolks.
Egg and cholesterol consumption and mortality from cardiovascular disease, cancer and all causes
Whole egg and dietary cholesterol intake were both positively associated with cardiovascular mortality. Egg white and substitute consumers had lower mortality than non-consumers, HR 0.93 (0.91–0.95), and substituting egg white for half a whole egg was associated with lower cardiovascular and cancer mortality. That substitution finding is the basis for the egg white rule.
8 studies
Where the evidence does not support LP3
These eight are here on purpose. Any diet book can assemble a reading list that agrees with it. What follows is the evidence that does not, with what each study can and cannot show.
Dairy Consumption and Risk of Cardiovascular and Bone Health Outcomes: an umbrella review and updated meta-analyses
Umbrella review of 33 meta-analyses. Total dairy, milk and yogurt were each associated with modestly reduced cardiovascular risk, and dairy was linked to higher bone mineral density. This does not support excluding dairy on outcome grounds — and it is listed here for that reason. Read the credibility column, though: the review itself rated the evidence weak for most of these associations, meaning the underlying studies were observational, heterogeneous, or both. LP3 excludes full-fat dairy for the saturated fat it carries, not on a claim that milk causes disease.
The dose-response relationship between dairy product intake and all-cause and cardiovascular mortality risk
Yogurt intake around 200 g/day was associated with lower all-cause and cardiovascular mortality, with fermented dairy performing better than non-fermented. This supports keeping the Greek yogurt exception.
Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies (BMJ, 2020)
Found moderate egg intake, up to about one a day, not associated with cardiovascular disease risk overall. This runs against the whole-egg exclusion and is listed here for that reason. Two things to weigh alongside it: it is observational and built on food-frequency questionnaires, and the larger NIH-AARP cohort above — 521,120 adults against roughly 215,000 here — found the opposite, along with lower mortality among egg-white consumers. The literature is split. LP3 rests the egg white rule on the substitution finding and on saturated fat, not on a claim that eggs cause heart disease.
Plant-based dietary indices and biomarkers of chronic low-grade inflammation (Kharaty et al., European Journal of Nutrition, 2023)
Higher-quality plant food intake was associated with lower inflammatory markers and lower-quality plant food with higher ones. Important caveat: the study is cross-sectional, and after correction for multiple testing none of the associations persisted. Cited in the book with that caveat attached.
FDA proposes to revoke the soy protein and coronary heart disease health claim (82 FR 50324, 2017)
The claim at 21 CFR 101.82 remains technically in effect, but the FDA proposed revoking it after concluding the evidence no longer met its standard, and that proposal has sat unresolved since. Tofu and tempeh are in LP3 as protein with the right fat profile, not on the strength of this claim.
Comparative Bioavailability of DHA and EPA from Microalgal and Fish Oil in Adults (Int J Mol Sci, 2025)
Plasma phospholipid DHA and EPA from microalgal oil were non-inferior to fish oil in 74 adults. This supports algal oil as a substitute for people who will not eat fish. It is a secondary analysis of an earlier randomized trial rather than a new one. Seaweed is not a substitute: a normal serving of nori or wakame delivers a small fraction of the EPA and DHA in a tin of sardines.
The effects of omega-3 polyunsaturated fatty acids on muscle and whole-body protein synthesis (Therdyothin et al., Nutrition Reviews, 2024)
Meta-analysis of randomized trials. Omega-3 supplementation showed no effect on muscle protein synthesis rates, although whole-body protein synthesis increased. It does not support a muscle-recovery claim, and LP3 does not make one — seafood is in this diet for cardiovascular reasons and for EPA and DHA, which nothing else on the plate supplies. Note also that these trials tested supplements, not fish as food.
Lack of evidence for omega-3 supplementation in enhancing lean mass, muscle strength and physical function: an overview of reviews
Most systematic reviews found no significant effect of omega-3 supplementation on strength, and no consistent effect on physical function. Same point: the case for seafood in LP3 is cardiovascular, and the case for muscle is protein and training. Anyone selling you fish oil for your bench press is overreaching.
Not ready to buy?
Six pages, free: the plate, the full contents, and one full day of meals with the recipes written out. No obligation, and you can read how the book is written before you buy it.
Rather not leave an address? Download it directly — no sign-up, nothing to unsubscribe from.