Probably the last time I'll bother writing a sincere answer to this kind of question. None of this is deep secret knowledge. Some people may genuinely not understand it, but I think many more pretend ignorance to strike a pose of moral superiority. Maybe my answer will benefit someone. For the lurkers, right?

https://www.quora.com/With-food-prices-so-high-how-do-the-poor-get-so-fat/answer/Daniel-Dvorkin-3