Passive Aggression, protein mix before/with each meal then limit your portions. Start making your own meals. Middle road, order "side salads" so you have a proper smaller portion. If a full meal must be had get the veggie/vegan option and again stick to the smaller portions if they insist on ordering out. Open Defiance, just start making your own food. Crock pots can be put in the corner of a bedroom or anywhere with an outlet. Get a bag of Crock pot liners so you don't have to clean it after each use. Instant oatmeal or cereal for breakfast so you're not dirtying pots. For drinks stick to the party rule, get yourself a cup and hold that in your hand or keep it near by/in front of you when everyone else is drinking. Ice water with plenty of ice or start mixing Gatorade. Best part about a cup of ice water with a lot of ice, the taste doesn't go bad as the ice melts. So you can "nurse it" for an hour or two.