So i got an idea for a special location that you can visit with a vehicle and in order to get in,you either need to pay a big number of money or be a very high position at Dizzy's and have a big national obesity level in order to enter.It can be something like an Area 51 thing and you can encounter an alien that you can fatten and it can fatten you too,the alien can have any personality in the game and interests and body type.It can be a late game milestone for dedicated players.
This is just a suggestion.