See PhysOrg: Increased food intake alone explains the increase in body weight in the US
How much of the obesity epidemic has been caused by excess calorie intake and how much by reductions in physical activity has been long debated and while experts agree that making it easier for people to eat less and exercise more are both important for combating it, they debate where the public health focus should be.
A study presented on Friday at the European Congress on Obesity is the first to examine the question of the proportional contributions to the obesity epidemic by combining metabolic relationships, the laws of thermodynamics, epidemiological data and agricultural data.
"There have been a lot of assumptions that both reduced physical activity and increased energy intake have been major drivers of the obesity epidemic. Until now, nobody has proposed how to quantify their relative contributions to the rise in obesity since the 1970s. This study demonstrates that the weight gain in the American population seems to be virtually all explained by eating more calories.
