It depends. You can deduct the cost of unreimbursed meals and laundry/dry cleaning expense when you are traveling away from home for business overnight. See this link for  a detailed discussion of travel expenses.

If your travel qualifies, you can use the GSA Per Diem Rates for the city where you stayed, for the Meals and Incidentals  (M& IE) rather than keeping receipts.

If you are an employee, this is an itemized deduction, so you must be able to itemize to claim these expenses. These are Employee Business Expenses, limited to the amount over 2% of your Adjusted Gross Income (AGI).  If you are self-employed, you would deduct the expense on your Schedule C.

You can deduct 50% of the actual cost of your meals, but there is no overall cap on the amount of the expense, as long as it is considered to be both ordinary and necessary. 

You would enter your expenses under Employment Expenses , and be sure to enter only the unreimbursed portion.