Take them cake and don't eat any.  This is great advice. Start showing up with cake,   d8  donuts, and treats every day or so, and hand them out to the fats. "Oh, me? I'm not having any, because of my conditions. These are just for you." If they ask what your condition is, just smil  eac  e and say "I have a slow metabolism; if I eat cake every day, I get fat."