When traveling, I make sure I bring along a variety of ziplocks, rubber bands and various sized twist-ties. These come in very handy for saving left-over snacks and other food, such as restaurant remnants. Ideally, I have along an ice chest for perishables.
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I sometimes travel for work and must stay at a hotel (and eat out). One of the first things I do is stop at the market and pick up some fruit and baby carrots so that I have healthy snacks for between meals to help offset the splurging.