For a more scholarly view, the current New England Journal of Medicine has a good article (full version only to subscribers or those with library access, it looks like).
It's really amazing what we don't know in terms of how our bodies work sometimes. For example, why are some people who exercise and eat correctly unable to lose weight? And do they still get a health benefit versus someone who might weigh the same, but sit on the couch and eat bags of potato chips. I do think a lot of the "fluffy" popular media articles actually do more harm than good. I'll leave it at that.