Brie Turner-McGrievy, PhD, an assistant professor at the University of South Carolina, followed 63 people on vegan, vegetarian, pesco-vegetarian, semi-vegetarian, and omnivorous diets for eight weeks. Participants stuck to low-fat, low-glycemic index foods without restricting or counting calories. The results? Vegans and vegetarians lost an average of 8.2 to 9.9 pounds while meat-eaters dropped an average of 5.1 pounds. Plus, two months after the study, the vegans, vegetarians, and pesco-vegetarians (vegetarians who eat fish) all lost more weight than omnivores. At six months, the vegans were only 30% to 40% adherent to the diet, yet continued to lose more than the other groups—they lost about 7.5% of their body weight compared to vegetarians, who dropped approximately 5.8%. Because the vegan diet is generally low in fat (which contains more calories per gram), it could explain why the vegans shed more pounds, Dr. Turner-McGrievy says. But there could also be something a bit more simple at play: the idea of following a diet that restricts certain foods—not calories. “The idea of being able to be on a diet where you can eat till you’re full and not have to self-monitor, even though it seems very extreme, is appealing to certain people. Some people find it very liberating,” Dr. Turner-McGrievy says. Christopher Gardner, PhD, an associate professor at the Stanford University School of Medicine, says becoming a vegan for social reasons—not just weight loss—makes it sustainable in the long term. (Need a little encouragement? These8 cruelest foods you eat will have you looking at meals in a whole new way.) If you’re looking to go vegan, pay attention to protein intake, suggests Sharon Palmer, a dietitian and author of The Plant-Powered Diet. A 150-pound person needs at least about 54 grams per day, and new research suggests even more can be beneficial. Make sure to choose nutrition-rich foods and eat high-calorie items—such as nuts—in moderation, Palmer says. Check out these 10 new meatless recipes to get started.