hmm, a difficult question Cluny, I agree with what Nahla has said about jealousy.

If you have no willpower it is easy to knock those that have. If you see them denying themselves cake, and you don't, (and you're larger than them) you get more guilt when you eat the cake, at least in my own experience.

Also, if you really crave trash food, it is hard to imagine that not everyone in the world also craves these things.

As an overweight person with a normal weight partner who passes a lot of comment on what I eat, I don't really know what to say, I was always taught it was rude to comment on what other people ate, or their lack of table manners for that matter. So, no help to offer you, sorry.