Travelling is such a nightmare - i have to do it too! You are jet lagged and all you want and need is a massive carb fix! I find that if you are really set out in your plan not to eat badly that you don't. Have fruit for breakfast and take a walk - it really sets me up, then I have eggs or something - something that keeps you full. Then the buffet lunches and dinners are the killer for me. I try to eat before I get to a buffet and then eat nothing while i'm there - that way if i don't start eating unhealthily i won't want to continue it!
Well that's what's worked the past couple of times i've travelled. Good luck and don't give in!!!! And don't eat the plane food - yuk!
Nicole