I agree this either needs tuning or an option to turn off completely. The way it is now, not only does it make it frustrating to play rotationally, since sims change physique every time they're left to their own devices, it takes away the fun of getting to have your sims try new food options in different worlds, etc, since you know they'll pay for it in instant weight gain if you don't force them to exercise after every meal/snack/drink (which sort of defeats the purpose of vacations and parties, and I also agree could be potentially triggering for people who have struggled with EDs).
