No one ever calls bullshit when fat people claim to eat normally.
What always makes me laugh is when office tubbies sit there pecking away at their meagre salads and dry rice cakes etc. as if that is what they'd eat out of sight of everybody. And if you prepare a proper lunch they say, "oh I couldn't possibly eat all
that food, I don't have a big appetite." as they sit there drooling, just waiting to get back to their car where they've got emergency food stashed - catering pack sized bars of chocolate etc. - to wolf down through the tears of shame...