A good gastric food to eat might be a bran muffin or flaxseed smoothie. These high-fiber recipes pack a punch that helps weight loss and digestion. Animal protein should also be eaten, including chicken, fish, turkey, eggs, and cottage cheese. These are the best foods to eat after a gastric bypass surgery because they have the protein that helps rebuild muscle tissue and facilitate wound healing. All diets after gastric bypass surgery should contain plenty of protein, fiber, and vitamins and minerals. Fruits, vegetables, and whole grains are good foods to eat. Stay away from sugary and sweet foods as these don't provide any vitamins or minerals.