It seems to me that you're forgetting a very important cause to obesity. The marketing campaigns led by big corporations such as Mac Donald's, Coca Cola and so on...
No doubt many researchers would agree: the food industry has contributed to the problem. Evidence points to manufacturers adding large quantities of sugars (in many forms) to convenience and fast foods as a major culprit.
Physiological effects of this intake result in greater synthesis of fatty acids which are easily stored in fat depots. Over time in vulnerable individuals the cumulative result is excessive adiposity and obesity.
There has been a push to reduce the sugar content of foods and educate the public about the risks. Consumers should learn to read nutrition labels and avoid products with high sugar content.
