It looks pretty good so far! I think a good improvement would be to make a clear goal for taking part in the food contest, other than to get bigger. Maybe a weight goal or an opponent who's getting bigger alongside your character.
Something like a tiny story mode where you climb up ladder of opponents who can eat more and faster than you until you need to face off the guy who at the beginning laughed you off when you lost to him by nearly 330 kilos could be nice too? Obviously as this is mostly a casual game there wouldn't be much of story itself and you couldn't make advancing further too hard.