Hm, interesting topic. I think I disagree with a lot of the posts with arbitrary ages for when the blame shifts, because your upbringing is so influential and most people won't be able to break habits formed. But I also don't like the idea of blaming your parents, for me endorsing the idea seems like enabling people to have an easy excuse for not taking responsibility of their health. So even though, yeah you're (general you, not you you) parents ****ed up and set you up for failure, the responsibility to handle it is now yours.
Plus, it's not so much your parents', but theirs and so on. For example, the latino diet (specifically Mexican since that's the one I've read about) has not been able to adapt to modern day food consumption and the adapting it is making is just taking in negative traits.

Plus genetics play a sizable (yet not major) part too. I think I'll just steal Guernica's Kind of yes kind of no.