When researchers at Loma Linda University conducted a cross-sectional study of 71,715 subjects from the Adventist Health Study 2 to compare nutrient intakes between dietary patterns characterized by consumption or exclusion of meat and dairy products, they found a clear connection between diet type and weight among five groups: meat-eaters, semi-vegetarians, pescatarians, lacto-ovo vegetarians, and vegans. Vegans were found to have the lowest average BMI, while meat-eaters showed the highest, along with the highest intake of heart-disease related fatty acids. Vegans also had the lowest occurrence of obesity (9%) compared to 33.3% of meat-eaters. The average age of study participants was 59.
Journal of the Academy of Nutrition and Dietetics. August 2013. (Rizzo, Jaceldo-Sigl, Sabate, Fraser.)