When I was traveling and living out of a hotel, I actually lost quite a bit of weight - I kept my protien/carb/fat at about 40/35/25 and daily calories around 1800 - 2000. For exercise I was following the program outlined in Mark Lauren's "You are Your Own Gym." It's a book of bodyweight exercises and programs. Another good one that I found later is "Never Gymless" and "Infinite Intensity" by Ross Enamiat, who also has a website with some really cool information including a section on homemade equipment (like TRX type straps, ab wheels). Those are useful programs that can be completed with a minimum of equipment.
When I was trying to lose a lot of weight, I always brought extra food, but they were healthy options like fruits and snack-type bars. Figured if I got hungry better to have something ok to eat then to find a candy bar! It may be easier for you to keep apples and granola bars around then to always fight the temptation to eat. I know it is for me, and usually when I break down, I really break down!