I read that blog series and it makes a decent case that there is some environmental contaminant that matters (or a combination of several), but it can't be the

I read that blog series and it makes a decent case that there is some environmental contaminant that matters (or a combination of several), but it can't be the whole story because things like gastric bypass definitely work. Also just from observing obese people eat it is clear that few of them eat in a way conducive to weight loss. Perhaps some environmental contaminant causes them to crave calorically dense, non-satiating foods, but that seems doubtful to me. Edit: The other thing I noticed when reading the series was that the author had a habit of discounting anything that refuted his thesis (calling it a minor effect and so forth), while giving greater credibility to similarly weak evidence for his theory.