Gastric bypass surgery helps severely obese patients lose weight by rearranging the digestive tract to block calorie absorption and restricting the size of the stomach. Your surgeon will instruct you to begin with a liquid diet to allow your digestive system to heal after surgery, progressing slowly to pureed, soft and finally regular foods, according to Linda Aills, R.D., lead researcher in a study published in the September 2008 issue of "Surgery for Obesity and Related Diseases."
To avoid losing lean muscle mass, you need at least 60 to 80 g of protein a day after gastric bypass surgery, says Aills. You may begin using protein supplements mixed with liquids within a day or two of your surgery and may continue to use them as needed for the rest of your life. Choose a complete protein source such as whey, casein, soy or egg whites. If you have lactose intolerance, select whey isolate rather than whey concentrate, or use the soy or egg white versions to avoid abdominal distress. Add fruits, flavorings and sugar-free syrups for variety, suggests Sinai Hospital.
Eggs prepared without extra fat provide an easily digestible form of protein. Use nonstick spray in your skillet to prepare fluffy scrambled eggs or an egg white omelet. Bake a breakfast casserole made of egg substitute mixed with shredded cheese, vegetables and Mexican sauce, or pour the mixture into muffin cups for individual-sized mini-casseroles. Avoid dry cooked eggs that may block the opening between the stomach pouch and the small intestines.
Meat and Fish
Flaky fish and tender cooked meat, including beef and poultry, provide protein that digests readily, according to Highland Hospital. Avoid dry, stringy meat that may block the opening between your stomach and intestines. Some patients cannot digest shrimp and other shellfish, so experiment with small amounts. High fat meats, including lunch meat, bacon and sausage, may cause dumping syndrome, an uncomfortable reaction to fatty or sugary foods that causes diarrhea, abdominal cramping, flushing and nausea, according to MayoClinic.com.
Fruits and Vegetables
Soft, cooked vegetables and fruits provide fiber and vitamins. Avoid fibrous vegetables such as broccoli, cauliflower, brussel sprouts, corn, cabbage, salad greens and asparagus if they do not digest well, says Highland Hospital. Choose fruits prepared without extra sugar or canned in their own juice. Avoid bananas and dried fruit because of their high sugar content.
Breads and Cereals
Cooked, sugar-free cereal such as oatmeal or cream of rice digests easily, as does cold cereal soaked in milk, according to Highland Hospital. Many patients find that soft breads, pasta and rice from a ball of dough that blocks the stomach opening, so avoid these foods or try them in small amounts. Breads and cereals with high sugar or fat contents, including doughnuts, pastries and sugary cereals, may cause dumping syndrome.
Low fat, low sugar dairy products provide protein. Choose non-fat or one percent milk, cottage cheese or artificially sweetened yogurt. Avoid full fat cheese and other milk products that may cause dumping syndrome, says Highland Hospital. If you have lactose intolerance, select milk alternatives such as soy or almond milk.
Most gastric bypass patients cannot digest snack foods such as popcorn, nuts, seeds and coconut, according to Highland Hospital. Avoid empty calorie, sugary or fatty foods such as potato chips, cakes, cookies and pies. Select soft fruits, vegetables without skins and protein sources if you must snack between meals.