Why? I'm 99.9% confident that they are trying to shame fit people. Which, there is no shame in being; if anything you should feel proud. I just stare at these pictures with their captions for them and just make this face.  Essentially what they are saying is, "Ha! Look at this person who understands moderation and treating themselves once in a while! They have self-control! What losers! #youdidnoteatthat"  Once again.