I think this is partially a defense mechanism. Ask yourself -- how have people been hurt in the past that might make them want to react aggressively to these s

I think this is partially a defense mechanism. Ask yourself -- how have people been hurt in the past that might make them want to react aggressively to these sorts of mentions? I think most people have, at some point in their lives, had someone treat them as morally inferior for their weight or their eating habits. So loudly extolling a positive perception of their experience is a way of creating a wall to preempt an attack on their character from a "superior" dieter/vegetarian/religiously-kosher/whatever type of person. Of course, this creates a vicious cycle. Just yesterday, someone offered to buy lunch for a friend of mine. He said it would have to be vegan, and the guy lost his temper. Like "how DARE you be one of those pushy types!" When the guy only said something because he was being offered food for himself to eat. Which perpetuates the cycle of distrust and mockery.