A common word in English for this category of expenses is "per diem," which means "per day" in Latin but is used to describe the daily expenses one might incur while traveling. It's mostly used in a corporate context, though, so it might not be appropriate here. It also includes more than food, like car tolls, parking fees, and maybe even lodging expenses.
Additionally, per diem expenses are typically a fixed dollar amount for each day, and you may not be expected to account for how you spent that money when submitting expenses. For example, if you had a $50 per diem, that would mean you have $50 per day for whatever little expenses came up, including your meals.
You could also use "Food & Drink" or "Meals" as an item on the list, allowing "expenses" to be inferred by the category of the list.