If you want to lose weight, and you’re willing to give up the traditional American way of eating, a vegan or vegetarian diet may be the way to go. Researchers from Harvard’s T.H. Chan School of Public Health conducted a meta-analysis to determine the effects of vegetarian eating on weight. They narrowed down 1,513 studies to the 12 most relevant trials comparing vegan diets or vegetarian plans (including eggs and dairy products) to the average American diet. The 12 trials included data on 1,151 individuals ranging in age from 18 to 82. Some were obese or diabetic. Analysis showed that people on vegetarian diets lost about 4.4 pounds within a year, while those on a vegan diet lost an additional 5.5 pounds during the same time frame. In the studies reviewed, the losses were compared to a control group with no changes in diet. In news reports, Frank Hu of the Harvard School of Public Health, an author of the investigation said that the meta-analysis didn’t compare the weight loss effects of vegan and vegetarian diets to a low carbohydrate, low fat or any other diet strategy, but found that they seemed to out-perform the average American diet.