No, obesity is a metabolic problem. And barring personal medical issues, diets of starch and sugar are the cause.

[EDIT], Folks, obesity is a result of metabolic disease. Obesity is an epidemic, and the science is abundant on this. This isn't a grammatic nuance, it's the essence of the global obesity epidemic that results from diet and eating habits. It's literally the foundation of the growing understanding amongst medical professionals of why low-carb diets and fasting work dramatically on this.