Gastric bypass surgery can result in long-term weight loss. The amount of weight you lose depends on your type of weight-loss surgery and the changes you make in your lifestyle habits. It may be possible to lose half, or even more, of your excess weight within two years.
The gastric bypass diet can help you recover from surgery and transition to a way of eating that is healthy and supports your weight-loss goals. Remember that if you return to unhealthy eating habits after weight-loss surgery, you may not lose all of your excess weight, or you may regain any weight that you do lose.
The greatest risks of the gastric bypass diet come from not following the diet properly. If you eat too much or eat food that you shouldn't, you could have complications. These include:
Feb. 20, 2015
- Dumping syndrome. This complication occurs most often after eating foods high in sugar or fat. These foods travel quickly through your stomach pouch and "dump" into your intestine. Dumping syndrome can cause nausea, vomiting, dizziness, sweating and eventually diarrhea.
- Dehydration. Because you're not supposed to drink fluids with your meals, some people become dehydrated. You can prevent dehydration by sipping 48 to 64 ounces (1.4 to 1.9 liters) of water and other low-calorie beverages throughout the day.
- Nausea and vomiting. If you eat too much, eat too fast or don't chew your food adequately, you may become nauseated or vomit after meals.
- Constipation. If you don't follow a regular schedule for eating your meals, don't eat enough fiber or don't exercise, you may become constipated.
- Blocked opening of your stomach pouch. It's possible for food to become lodged at the opening of your stomach pouch, even if you carefully follow the diet. Signs and symptoms of a blocked stomach opening include ongoing nausea, vomiting and abdominal pain. Call your doctor if you have these symptoms for more than two days.
- Weight gain or failure to lose weight. If you continue to gain weight or fail to lose weight on the gastric bypass diet, it's possible you could be eating too many calories. Talk to your doctor or dietitian about changes you can make to your diet.
See more In-depth
- Bariatric surgery for severe obesity. National Institute on Diabetes and Digestive and Kidney Diseases. http://win.niddk.nih.gov/publications/gastric.htm. Accessed Jan. 19, 2015.
- Lim RB. Bariatric surgical operations for the management of severe obesity. http://www.uptodate.com/home. Accessed Jan. 19, 2015.
- Hamad G. Bariatric surgery: Postoperative and long-term management of the uncomplicated patient. http://www.uptodate.com/home/. Accessed Jan.19, 2015.
- Kushner RF, et al. Bariatric surgery: Postoperative nutritional management. http://www.uptodate.com/home. Accessed Jan. 19, 2015.
- Mechanick JI, et al. Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient — 2013 update: Cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery. Surgery for Obesity and Related Disorders. 2013;9:159.
- AskMayoExpert. Bariatric surgery. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Barbara Woodward Lips Patient Education Center. Nutritional guidelines after bariatric surgery. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2010.