Travel and Weight Loss

I am on a job which is requiring 12 weeks of travel. I am staying in a hotel that provides breakfast...I am trying to live with the motto "eat like a king for breakfast, a regular person for lunch and a pauper for dinner. I am averaging 450 calories for breakfast, 400-500 for lunch, but on days that I don't work out, I am left with 300 some calories for dinner and that is if I have fruit for lunch! I am feeling like I am being healthy in my choices, but what am I doing wrong that I have so few calories at the end of the day? Is it the simple fact that I am not working out EVERYDAY?

Work is about to pick up to be 12 hr days, please help!