i don't know if this has been suggested yet, but i think it'd be cool if you have player weight gain enabled, you either passively gain or lose weight depending on how hungry your character is
Optional passive Weight-gain/loss for all game characters could be intereseting.
This would make the game more realistic but i'm not sure if it is good for the gameplay loop. Thats why it could be an option and not forced.
My humble opinion.
edit: Just remembered:
Passive gain is already kind of there with DDD addiction.
When the fitness center will be available i guess that will be passsive loss.