How Not to Diet

by Michael Greger

Are the lower disease rates associated with plant-based eating due directly to the diet itself or indirectly to the ease of weight loss and maintenance? To find control groups of individuals eating typical diets who were as slim as a group of whole-food vegans, studies have had to recruit long-distance endurance athletes running an average of forty-eight miles per week for twenty-one years. Apparently, people who run the equivalent of almost two marathons a week for two decades can be as slim as a vegan no matter what they eat! What’s more, the purely plant-based eaters in the studies were sedentary, exercising for less than an hour a week.2478 So run two thousand miles a year, and your weight may rival that of some vegan couch potatoes? What’s their secret? The simplest explanation is that those eating more plant-based may just be eating fewer calories—as many as 464 fewer calories a day, in fact.2479 That would certainly do it. That’s nearly the 500-a-day caloric restriction recommended in the federal dietary guidelines for weight loss.2480 But this calorie reduction was achieved without significantly changing the amount of food eaten. Some studies show that those eating purely plant-based diets are actually eating nearly a half pound more food a day compared to nonvegetarians.2481 That’s the beauty of foods with low calorie density: more food, less weight.