VEGPREV Study Reveals the Most Effective Diet for Weight Loss

Back in early 2025, a European weight loss study called the VEGPREV study was created in order to compare different diets and discover which led to the most weight loss. Over the course of 12 weeks, they split people into different groups, each following one of these 5 diets: Mediterranean diet, 100% plant-based vegan diet, eco-friendly regimen created by nutritionists, vegetarian diet with eggs and dairy, and 1 control group (consuming the regular Western diet).

The group that showed the most weight loss the fastest was the vegan group that followed a 100% plant-based diet. The participants lost 6.7% body fat. The study also found significant reductions in fat mass (body fat percentage) across all plant-based groups, and the vegan diet showed some of the strongest improvements in body composition.

There are a myriad of reasons why the plant-based vegan diet was most effective for weight loss.

Some of the reasons include:

•  Higher fiber- They were fuller faster, with a significantly lower calorie intake (i.e., vegetables/fruits have high fiber and high-water content, which makes you full faster but with lower calorie intake—so they wound up eating less.
•  Reduced inflammation - processed foods and stress cause inflammation throughout the body, which leads to a myriad of health issues, one of them being weight gain. By eliminating it from their diet and introducing vegetables, seeds, nuts, etc. to the diet instead, it led to a reduction of inflammation (which can show up as water retention, bloating, etc.) and an overall healthier, leaner appearance.
•  High in Polyphenols- vegan and plant based diets are usually composed of mostly vegetables, fruits, seeds and grains. Vegetables like greens and nuts contain naturally occurring polyphenols, which help combat inflammation. Polyphenols are a class of antioxidants that help boost metabolism, improve digestion and cardiovascular health. Olive oil is also an excellent source of polyphenols, as is red wine. Whole wheat bread is another good source of polyphenols, in particular, a type known as phenolic acids. As far as beverages goes, green tea is an incredibly powerful source of polyphenols . Polyphenols, specifically the catechins found in green tea, activate a process in the body called thermogenesis, where your body burns calories in order to increase body heat, which leads to weight loss.