Food is certainly one of the greatest expenses while traveling.
Unless you're subletting an apartment, house-sitting, or staying at a hotel equipped with a kitchenette, you have to eat all your meals out. In Europe it's easy to orchestrate wonderful meals on a tight budget by buying fresh produce and baked goods and making a picnic. In the U.S., too, picnics, delis, and cheap chains make for lighter food budgets. But sometimes going out to restaurants is a more convenient, self-pampering, and simply relaxing way to eat. But if you spend more than a day or two eating all of your meals out, you'll soon find that the luxury of restaurants adds up to a pretty penny pretty quickly.