I believe only a small percentage of it really is a "disease" (for lack of a better word) related issue. Mostly us Americans are lazy over eaters that don't exercise. Furthermore the types of foods we eat aren't as health as other nations and these are the primary drivers of the obesity rate being so high. Again I am not say that all obese people are lazy, or eat too much. I fully understand and know that some people have a "disease" but a majority of people can't really say that in my opinion.