I used to be the 'broke friend' there wasn't abudget there just wasn't a single cent
. Anyway I picked up a trick or two if your interested.
1. go grocery shopping before hand, bread, spreads, bars and such are pretty cheap and pack well.
2. drink water, order cheap, fill up in the room on the snacks you packed. (the excersize of sking pays off the extra calories if any
.)
3.enjoy the dieters leftovers, on vacation they arn't taking them home, though this step is a sure clue to fill your friends in that you are broke