It is unfortunately true that millions of Americans are obese due to excessive consumption of greasy, salty, unhealthy foods. At this point, I don't think many people can plead ignorance to the negative health impacts of such a diet. I commonly read that many people are too poor to afford healthy food, but the cost of fast food isn't very cheap at all either. Nothing wrong with treating yourself, but most people, with a lifestyle that is unprecedentedly sedentary and rich compared to most of human history (seriously, in what other era did the poor eat themselves to death?) would be better off eating less in general and what they do eat, make it something healthier than Domino's or McDonald's.
Our fellow citizens' lack of self-discipline will really come back to bite us in the collective behind if we ever need to institute a draft to defend our existence.