Vegan vs Mediterranean: The Best Diet For Weight Loss

Compared to a Mediterranean diet, this diet works better for weight loss and blood glucose levels.

Compared to a Mediterranean diet, this diet works better for weight loss and blood glucose levels.

A head-to-head comparison of the vegan diet with the Mediterranean diet shows that the vegan diet is superior for weight loss.

A low-fat vegan diet can cause weight loss, improve body composition, reduce cholesterol levels, and lower blood sugar levels more than a Mediterranean diet.

A study put a group of overweight adults on either a Mediterranean diet or low-fat vegan diet for 16 weeks.

The low-fat vegan diet was completely free from animal products and consisted of whole grains, vegetables, fruits, and legumes.

They also received vitamin B12 at a dosage of 500 µg per day during the entire study period.

The energy content of the vegan diet was from carbohydrates (75 percent), protein (15 percent), and fat (10 percent).

The Mediterranean diet plan was similar to the PREDIMED study (Prevention with Mediterranean Diet).

It consisted of low-fat dairy, legumes, fruits and vegetables, nuts or seeds, extra virgin olive oil, whole-grain cereals, eggs, and fish but saturated fats and red meat were avoided or limited to one serving per week.

All participants continued their routine exercises and didn’t need to change their regular medication unless told by their doctors.

Here is a summary of findings:

  • The Mediterranean diet didn’t cause any changes in weight but when participants followed the vegan diet they lost 13 pounds (6 kg).
  • The low-fat vegan diet led to a greater reductions of fat mass by 7.5 pounds (3.4 kg).
  • The vegan diet also caused a 315 cm3 reduction in visceral fat.
  • The vegan diet led to a reduction of total cholesterol and LDL (“bad” cholesterol) by 18.7mg/dL and 15.3 mg/dL respectively whereas the Mediterranean diet didn’t cause any changes in cholesterol levels.
  • Both diets caused lowered blood pressure with the Mediterranean diet being more effective than the vegan diet, 6.0 mm Hg compared to 3.2 mm Hg.

Dr Hana Kahleova, the study’s co-author, said:

“Previous studies have suggested that both Mediterranean and vegan diets improve body weight and cardiometabolic risk factors, but until now, their relative efficacy had not been compared in a randomized trial.

We decided to test the diets head to head and found that a vegan diet is more effective for both improving health markers and boosting weight loss.”

The researchers suggest that the weight loss from the vegan diet is related to its fewer calories, higher fibre, and lower fat intake.

Dr Neal Barnard, the study’s author, said:

“While many people think of the Mediterranean diet as one of the best ways to lose weight, the diet actually crashed and burned when we put it to the test.

In a randomized, controlled trial, the Mediterranean diet caused no weight loss at all.

The problem seems to be the inclusion of fatty fish, dairy products, and oils.

In contrast, a low-fat vegan diet caused significant and consistent weight loss.”

About the author

Mina Dean is a Nutritionist and Food Scientist. She holds a BSc in Human Nutrition and an MSc in Food Science.


The study was published in the Journal of the American College of Nutrition (Barnard et al., 2021).


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This site is all about scientific research into how the mind works.

It’s mostly written by psychologist and author, Dr Jeremy Dean.

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