Gastric Bypass Diet Plan

People who have undergone gastric bypass surgery have to make changes in how and what they eat, as well as how much they consume 13. Gastric bypass diets are created to deal with the specific nutritional needs of bypass patients 13. People can lose weight quickly after a gastric bypass, but face serious digestive and health complications if they don't strictly follow the diet 123.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Gastric Bypass Surgery

Gastric bypass surgery is the most frequently performed bariatric surgery in the United States, according to the Mayo Clinic 13. Patients undergo gastric bypass under general anesthesia, so they are unconscious during the procedure 13. During a Roux-en-Y gastric bypass, surgeons staple the stomach across the top, sealing it from the rest of the stomach, leaving a pouch big enough to hold roughly one ounce of food 13. The surgeon then removes the rest of the stomach and connects the small intestine to the newly re-sectioned pouch. Attaching the small intestine to the pouch allows food to bypass the stomach and the duodenum. Food enters directly into the jejunum, the second section of the small intestine, which limits the calories the body can absorb.


For the first one to two days following surgery, patients are on a liquid diet that includes broth, unsweetened juice, cream soups and gelatin; the patient sips only two to three ounces at a time. When the physician feels the patient is ready, she can move on to soft foods such as canned or soft fruits and cooked vegetables. This phase lasts approximately eight weeks. People gradually begin to eat firmer foods and build up a tolerance to spicy and crunchy foods.

Foods to Avoid

After gastric bypass, people should avoid certain foods that can irritate the stomach 13. Nuts and seeds, popcorn and dried fruits often cause gastrointestinal upset. People should avoid soda and carbonated beverages, as well, according to the Mayo Clinic.


People must keep meals small to avoid stretching the stomach and avoiding an upset stomach. Physicians recommend vitamin and mineral supplements following surgery to make up for the fact that bypassing part of the small intestine reduces absorption of nutrients. Patients should drink liquids between meals instead of with meals, as the combination can lead to nausea and vomiting, as well as causing people to feel full before ingesting the proper amount of nutrition. It's important to eat slowly and chew foods thoroughly, and introduce new foods one at a time to gauge how well the body responds, and to avoid foods high in fat and sugar and focus instead on high-protein meals.


Following gastric bypass people are at risk for nausea, vomiting and constipation 13. Another risk for gastric bypass patients is a disorder known as dumping syndrome; according to the Mayo Clinic, dumping syndrome occurs most often after eating high-fat or high-sugar foods 13.