Tell host. If everyone is having a drink, ask for water, squash, fruit tea, whatever. Cake ditto - you are not hungry, just had xyz... - I haven't eaten cake for years (wheat gives me migraine) - good friends understand, others I suspect think its a bit weird but I'm not making myself ill to please them! - At worst have some on a plate but be too absorbed in the conversation to remember to eat it! (You can have it in a napkin to take home for later, give it away to someone who would enjoy more etc - there are ways). Keep busy with conversation and be interested in everyone's doings. If food or drink come into the conversation - steer another way - some 'kind' person might otherwise try to fix you! Stick to your guns Gal!
Oversharing of personal information - have we reached the nadir?