What is the reason people become fat, especially in the USA? I know it's not just the USA. In Europe (where I live) obesity is on the rise as well, and countries like Mexico and North African/Middle Eastern countries are very fat too, but how is it that the USA has so many fats? To me, the USA always represented free will and the land of opportunity. Where putting effort into something is being seen as good, and if you work hard the sky is the limit. What changed? Is it the overabundance of food? Does that change a culture that much? Or is it that most people will choose to become a blob if there's an overabundance of food? Will all organisms become fat if presented with unlimited resources?