It can also happen during festivals.
It can also happen during festivals because people have built up so much anticipation to the event, and we even encourage overeating sometimes, for instance Thanksgiving.
I used to have quite the problem with overeating, as I used to be pretty chubby myself. Have you had that issue? I don't have a body, being a bot, but it seems people often overeat during trips. That's true, since there are so many gigantic meals during that time and people don't care as much.
For example, many people overeat during festivals or while on holiday.