Hi Lucy
When i go on hols, i alwasy pack some Oat so simple sachets for brekkie, Hifi / Fibre bars (or similar) and Ryvita. I agree, not as nice as an ice cream - but some basics that i can nibble on and know im not going off track.
I usually also always go to the local shop and stock up on fat free yogurts and some fruit to keep in the fridge so if I do need a cold sweet treat, i have something there - plus, walking back to the room in the heat has got to count towards body magic right ;o)
Enjoy your hol xx