 We know vegetarians have considerably lower obesity rates compared to those that eat meat. But why? Is it because they're not eating meat? Or because they're eating more plants? Or maybe they're just eating fewer calories or exercising more? This study controlled for all that. In essence they took men and women who ate the same number of calories a day, ate the same amount of vegetables and fruit, grain, same amount of exercise, but ate different amounts of meat. Men and women who ate less than a single serving a day of meat were on average not overweight, but the more meat they ate, the heavier they were, and by one and a half servings a day they'd cross the threshold, a BMI of 25, to become officially classified as overweight. Which type of meat was the worst? If you remember back to that study of hundreds of thousands of men and women, poultry consumption appeared to be the worst. Maybe it was reverse causation, meaning obesity led to greater chicken consumption, not the other way around. This new study controlled for that, adjusting for dietary habits, yet found the same thing. Chicken consumption was most associated with weight gain in both women and men, and it didn't take much. Compared to those who didn't eat any chicken at all, those eating about 20 or more grams of chicken a day had a significantly greater increase in their body mass index. That's around one chicken nugget, or a single chicken breast, once every two weeks, compared to no chicken at all.