While you road warriors don’t need to stay in five-star hotels or penthouse suites, you can choose a hotel chain that offers rooms/suites with a fridge (at least) or even a full kitchenette. Then just take a short walk to the shops after you deposit your luggage as you should have choose a hotel near the grocery store already. Then you can eat as well as you would have at home.
Even if you can’t find or afford a hotel with a kitchenette, as long as you have a refrigerator, you can stock the room with good snacks. Pop to the store and pick up fresh fruit and vegetables, bottled water, cottage cheese, plain yogurt, roasted chickpeas, regular cheese, natural peanut butter, whole-grain breads, sliced chicken or turkey, milk and mixed nuts. Canned fish can round out the protein options.