Why We’re Fat: Study Says Calories, Not Lack of Exercise

And in the continuing, read “eternal” debate about why we’re fat, a new study by a Yale anthropologist suggests that it’s much more about calories than lack of exercise. A Yale news release reports that the study puts to bed the theory that we modern humans burn far fewer calories than our hunter-gatherer ancestors. Using state-of-the-art technology to measure the daily energetic expenditure of the Hazda, a foraging people of Tanzania, the researchers discovered that even though these last remaining hunter-gatherers in Africa are quite physically active, they expend no more calories in a day than the adult population of the industrialized world. Given the total lack of obesity among the Hadza, whose average daily calorie consumption is far lower than that found in the developed world, the researchers concluded that increased caloric intake is the main source of rising obesity in Western populations. Lead author Brian Wood says the finding has huge evolutionary implications, because our evolved preference for energy-dense foods poses risks as such foods become increasingly easy to acquire. “Ultra-convenient, modern food markets are novel in an evolutionary sense,” he says. “Today we might get pleasure from a diet that over-supplies us with calories.” It’s possible. Read more from Yale here.