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Mediterranean diet vs plant based: what the doctors say
The Mediterranean diet beside a plant based diet: what McDougall, Esselstyn, Barnard, Novick and other doctors say on olive oil and PREDIMED, with sources.
Updated . For education only, not medical advice.
Our view
The Mediterranean diet is usually sold as olive oil, nuts, fish and a glass of wine, yet the doctors on this site keep pointing back to what the old village diets were mostly made of: bread, beans, vegetables and fruit123. In their reading, the good results credited to the pattern come from its plant foods, while the oil gets the praise456.
We give most weight to the low-fat doctors who have treated patients this way for decades, and on this topic they speak with one voice: a Mediterranean diet beats the typical Western one but is not the best a person can do789. Caldwell Esselstyn, John McDougall, Jeff Novick and Jeff Nelson have each taken apart the trials behind the reputation, chiefly the Lyon Diet Heart Study and PREDIMED10111213.
The strongest support in this guide comes from David Jenkins, who reads PREDIMED as a well-run randomized trial in which olive oil and nuts went with fewer heart events14. The only head-to-head trial here, run at Neal Barnard’s group and led by Hana Kahleova, found that people lost weight on a low-fat vegan diet and not on the Mediterranean one15.
Where they agree
Nearly all of them separate the diet’s foods from its oil: Ornish praised its fruit, vegetables, grains and beans in 1999, Goldhamer and McDougall called it healthy in spite of its olive oil, and Barnard told listeners in 2023 to keep the pasta and chickpeas while holding the oil low54116. They also agree that the original pattern held far less oil than today’s versions; Barnard said the oil used in the 1950s was minor, and Novick described Cretans of that decade as poor, hard working people eating mostly plants162.
Most of them accept that the pattern is a step up from the American diet: Ornish called it better but short of optimal, Rogers said a plant based version will add years compared with standard American food, and Campbell noted that Mediterranean countries still had more disease than rural China789. The low-fat doctors also agree that the trials never tested anything close to their own diet: Campbell said almost nobody in such studies eats whole plant foods, and Nelson pointed out that PREDIMED had no arm near 10% fat1718.
Where they differ
The real disputes are about what the big trials proved, whether olive oil deserves any credit, what the diet does for weight, and whether lowering risk in a population means much for someone who already has heart disease14121519.
What PREDIMED showed
Jenkins described PREDIMED in 2026 as a randomized trial of the usual Spanish diet with extra virgin olive oil or nuts added, with fewer heart and stroke events in both groups and also fewer deaths in the olive oil group14. McDougall in 2013 and Novick the same year read it differently: industry supplied the oil and nuts, only strokes fell, and the comparison group still took about 37% of its energy from fat1112. In his 2018 webinar Esselstyn added that all three groups, people with no heart diagnosis at entry, still had many heart attacks, strokes and deaths over five years20. By 2026 Nelson summed up that the touted 30% drop was about two points over five years, mostly strokes, and that the 2013 paper was withdrawn in 2018 and republished after a flaw in how part of the sample was randomized2122. Barnard drew yet another lesson: in PREDIMED, those whose eating leaned most toward vegetarian had the lowest death rates23.
Olive oil
Ornish argued in 1999 that olive oil brings more omega-6 than omega-3, of which it has next to none7. Goldhamer wrote in 2011, and repeated in 2025, that olive oil diets do better because they push out some meat, a mistake of attribution in his eyes424. Novick went furthest: in 2010 he labeled both the oil and the diet built around it a hoax25. Rip Esselstyn’s PLANTSTRONG site, reporting his 2025 debate on olive oil, has him asking what the oil is being compared with, since the studies usually set it against butter or lard26. The same page allows that a small amount may help someone who follows a Mediterranean diet, while steering people reversing heart disease or losing weight to no oil27.
Weight
In Kahleova’s randomized crossover trial of overweight adults without diabetes, each diet lasted 16 weeks; the vegan phase brought an average loss near 6 kilograms, the Mediterranean phase none, while blood pressure dropped on both and more on the Mediterranean one1528. Her 2024 follow-up traced the vegan diet’s lower load of advanced glycation end-products mostly to cutting meat, then added fats and dairy29. McDougall had argued in 2013 that trading one fat for another does not slim anyone down30. Rogers in 2026 recalled that in his thirties a loosely Mediterranean way of eating took off some, not all, of his excess weight, then moving on to McDougall’s starch-based approach31.
Lowering risk or reversing disease
Esselstyn, in a talk excerpt posted in 2016, set the Lyon Diet Heart Study, where one patient in four had died or suffered a heart attack or stroke by year four, against well under one percent among his own adherent patients10. Novick had written in 2006 that the Lyon diet was not built around olive oil at all32. Nelson, in 2026, said Crete and North Karelia showed whole populations lowering their risk, which is not the same as reversing disease already present19.
Then and now
In 1999 Novick wrote that the diet has no clear definition and that the Crete of the late 1950s, with people walking about nine miles a day, no longer exists2. Barnard, in 2021, traced the idea to Ancel Keys’s work in Italy and said today’s picture of it is far oilier than what Keys saw3. McDougall wrote in 2016 that the region’s children and adults now rank among the heaviest in the world1. Rogers, in 2026, said modern versions often reach about 40% of calories from fat33.
What each expert says
JMJohn McDougall
In April 2013 McDougall picked apart PREDIMED, noting the donated oil and nuts and that heart attacks and total deaths did not fall11. He also pointed to a study of obese women in the region whose fat came more than half from olive oil30. In 2016 he wrote that the diet was healthy in the past because of its starches, vegetables and fruit, not the oil and nuts now marketed with it1.
Esselstyn does not treat the Mediterranean diet as heart protection, citing the event rate in the Lyon trial against his own patients’ results10. Asked about PREDIMED in 2018, he said a study whose groups all piled up heart attacks and deaths was hardly about prevention20.
In a 2003 talk Campbell said he had a minor early role in the Mediterranean diet research done at Harvard34. He doubted that olive oil was the answer, since these populations also eat many plant foods yet still had more disease than rural China69. In 2013 he said such studies include almost no one eating whole plant foods17.
Barnard sees the original diet as Keys described it, with little red meat and olive oil replacing butter, and modern versions as much oilier3. His group’s trial found weight loss on a low-fat vegan diet and none on the Mediterranean diet35. In 2023 he called adding extra olive oil a mistake16.
On Fresh Air in 1999 Ornish gave the credit to the diet’s plants rather than its olive oil and called it better than the American diet but not optimal57. Writing in 2008, he granted some merit to each of the Atkins, Mediterranean and low-fat diets, and that the ideal borrows the omega-3s from it, keeps saturated fat low and fills up on plants36.
Goldhamer wrote around 2011 that Mediterranean benefits come from diets close to vegetarian and happen despite the olive oil, and that heated oils can form harmful byproducts4. In 2025 he called olive oil less bad than some foods but still not healthy24.
Rogers called faith in the Mediterranean diet the most common pitfall he sees in his 2026 talk on heart attacks37. He still grants that a plant based version beats the standard American diet, and calls the term vague8.
Novick has challenged the diet’s reputation since 1999, starting from what Cretans actually ate and how much they walked2. He wrote that the Lyon trial was misreported in 2006 and that PREDIMED’s so-called low-fat group was neither low in fat nor well supported in 20133212.
In a 2026 video Nelson went through PREDIMED’s tables: both Mediterranean groups ate about 41% fat and the control group about 37%38. He noted the free industry food and counselling for the two Mediterranean groups, while the control group at first got only a leaflet39. He found no significant differences in heart attacks or deaths13.
In the 2025 olive oil debate reported on his PLANTSTRONG site, Rip Esselstyn argued for no oil and asked what olive oil is being compared with26. The site’s summary leaves a little olive oil to people on a Mediterranean diet but recommends none for heart disease reversal or weight loss27.
Speaking in 2026, Jenkins recalled that a Mediterranean diet was one of three model patterns chosen by the US dietary guidelines committee of 201540. He described PREDIMED as a randomized trial showing fewer cardiovascular events with extra virgin olive oil or nuts, and lower total deaths with the oil14.
Kahleova led the crossover trial that put a low-fat vegan diet up against the Mediterranean one, and in 2024 said it undercuts the belief that the Mediterranean diet wins for weight loss1529. In 2025 she reported that the vegan diet still won even with refined grains and potatoes, and a 2024 analysis she led found it cost over $870 a year less4142. In 2020 she said reviews favor both plant based and Mediterranean diets in pregnancy43.
The doctors here agree that the healthy core of the old Mediterranean diet was its beans, grains, vegetables and fruit, and the low-fat doctors would keep those and leave out the added oil16124. Whether olive oil has a place, and what PREDIMED proved, are the points where they differ, so questions about your own heart or weight belong with your own doctor. This page is education, not medical advice.
Each small number links to its reference below: the video at the exact second, or the page where it was said.