Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Gastric bypass diet
By Mayo Clinic staffDefinition
The gastric bypass diet is specially designed for people who have just had gastric bypass surgery. What you eat, how you eat and how much you eat changes after gastric bypass surgery — surgery that changes the structure of your digestive system to help you lose weight.
With your stomach smaller or bypassed, you'll need to change your eating habits after gastric bypass surgery. A registered dietitian can help you create a meal plan, which includes what type and how much food to eat with each meal and the required consistency and texture of the food. Closely following your gastric bypass diet can help you lose weight safely.
Purpose
The gastric bypass diet has several purposes:
- To allow the staple line in your stomach to heal without being stretched by the food you eat
- To get you accustomed to eating the smaller amounts of food that can be digested comfortably and safely in your smaller stomach
- To help you lose weight and avoid gaining excess weight
- To avoid side effects and complications
The diet begins with liquid foods and allows you to eat progressively more solid foods.
Diet details
Diet recommendations after gastric bypass surgery may vary between medical centers. Most commonly, the gastric bypass diet has four phases to ease your way back to eating solid foods after your gastric bypass surgery. How quickly you move from one step to the next depends on how fast your body adjusts to the change in eating patterns and the texture and consistency of food. People usually start eating regular foods with a firmer texture three months after surgery, but it can occur sooner.
Phase one: Liquid diet
You won't be allowed to eat for one to two days after your gastric bypass surgery so that the staple line in your stomach can start to heal. After that, while you're still in the hospital, you'll start a diet of room temperature liquids and semisolid foods to see how you'll tolerate foods after surgery. The foods you can eat include:
- Broth
- Unsweetened juice
- Milk
- Strained cream soup
- Sugar-free gelatin
During phase one, sip fluids slowly and drink only 2 to 3 ounces (59 to 89 milliliters, or mL) at a time.
Phase two: Pureed (ground up) foods
Once you're able to tolerate liquid foods for a few days, you can begin to eat pureed foods. During this two- to four-week-long phase, you can only eat foods that have the consistency of a smooth paste or a thick liquid, without any distinct pieces of food in the mixture. To puree your foods, choose solid foods that will blend well, such as:
- Lean ground meats
- Beans
- Fish
- Egg whites
- Yogurt
- Soft fruits and vegetables.
Blend the solid food with a liquid, such as:
- Water
- Fat-free milk
- Juice with no sugar added
- Broth
- Fat-free gravy
Keep in mind that your digestive system might still be sensitive to spicy foods or dairy products. If you'd like to eat these foods during this phase, add them into your diet slowly and in small amounts.
Phase three: Soft, solid foods
With your doctor's OK, after a few weeks of pureed foods, you can add soft, solid foods to your diet. If you can mash your food with a fork, it's soft enough to include in this phase of your diet. During this phase, your diet can include ground or finely diced meats, canned or soft, fresh fruit, and cooked vegetables.
You usually eat soft foods for eight weeks before eating foods of regular consistency with firmer texture as recommended by your dietitian or doctor.
Phase four: Solid foods
After about eight weeks, you can gradually return to eating firmer foods without pureeing them. You may find you'll have difficulty eating spicier foods or foods with crunchy textures. Start slowly with regular foods to see what foods you can tolerate.
Avoid these foods:
- Nuts and seeds
- Popcorn
- Dried fruits
- Sodas and carbonated beverages
- Granola
- Stringy or fibrous vegetables, such as celery, broccoli, corn or cabbage
- Tough meats or meats with gristle
- Breads
It's possible that foods that irritate your stomach at first may become more tolerable as your stomach continues to heal.
Throughout the phases
To ensure you get enough vitamins and minerals and keep your weight-loss goals on track, throughout each phase, you should:
- Keep your meals small. During the diet progression, you eat many small meals a day and sip liquids slowly throughout the day (not with meals). You might first start with six small meals a day, then move to four meals and finally, when following a regular diet, decrease to three meals a day. Each meal should include about a half-cup to a cup of food. Make sure you eat only the recommended amounts and stop eating before you feel full.
- Take the vitamin and mineral supplements recommended. Because a portion of your small intestine is bypassed after surgery, your body won't be able to absorb enough nutrients from your food. You'll need to take a multivitamin supplement every day for the rest of your life, so talk to your doctor about what type of multivitamin might be right for you, and whether you might need to take additional supplements, such as calcium.
- Drink liquids between meals. Drinking liquids with your meals can cause pain, nausea and vomiting as well as dumping syndrome. Also, drinking too much liquid at or around mealtime can leave you feeling overly full and prevent you from eating enough nutrient-rich foods. Expect to drink at least 6 to 8 cups (48 to 64 ounces or 1.4 to 1.9 liters) of fluids a day to prevent dehydration.
- Eat and drink slowly. Eating or drinking too quickly may cause dumping syndrome — when foods and liquids enter your small intestine rapidly and in larger amounts than normal, causing nausea, vomiting, diarrhea, dizziness and sweating. To prevent dumping syndrome, choose foods and liquids low in fat and sugar, eat and drink slowly, and wait 30 minutes before or after each meal to drink liquids. Take at least 30 minutes to eat your meals and 30 to 60 minutes to drink 1 cup (237 milliliters) of liquid. Avoid foods high in fat and sugar, such as regular soda, candy and candy bars, and ice cream.
- Chew food thoroughly. The new opening that leads from your stomach into your intestine is very small, and larger pieces of food can block the opening. Blockages prevent food from leaving your stomach and could cause vomiting, nausea and abdominal pain. Take small bites of food and chew them to a pureed consistency before swallowing. If you can't chew the food thoroughly, don't swallow it.
- Try new foods one at a time. After surgery, certain foods may cause nausea, pain, vomiting or may block the opening of the stomach. The ability to tolerate foods varies from person to person. Try one new food at a time and chew thoroughly before swallowing. If a food causes discomfort, don't eat it. As time passes, you may be able to eat this food. Foods and liquids that commonly cause discomfort include meat, bread, pasta, rice, raw vegetables, milk and carbonated beverages. Food textures not tolerated well include dry, sticky or stringy foods.
- Focus on high-protein foods. Immediately after your surgery, eating high-protein foods can help heal your wounds, regrow muscle and skin, and prevent hair loss. High-protein, low-fat choices remain a good long-term diet option after your surgery, as well. Try adding lean cuts of beef, chicken, pork, fish or beans to your diet.
- Avoid foods that are high in fat and sugars. After your surgery, it may be difficult for your digestive system to tolerate foods that are high in fat or added sugars. Avoid foods that are fried and look for sugar-free options of soft drinks and dairy products.
Results
Within the first two years following surgery, you can expect to lose 50 to 60 percent of your excess weight, if you follow the dietary and exercise recommendations. If you continue to follow these recommendations, you can keep most of that weight off long term.
People who regain weight after gastric bypass surgery usually are consuming too many high-calorie foods and beverages and don't exercise enough. And rather than eating three meals a day and perhaps a planned healthy snack, some people eat food all day long.
Successful weight management requires the following healthy habits:
- Reduce unplanned snacking.
- Exercise regularly.
- Attend regular follow-up appointments with your health care provider to review your symptoms and progress and to make sure you don't have any vitamin or mineral deficiencies.
If you aren't losing weight or are regaining weight after surgery, see your doctor. He or she can help watch your eating behaviors and exercise habits and help you confront and overcome any weight-loss obstacles.
Although weight-loss surgery helps you shed pounds, its success depends on your willingness to adopt lifelong healthy-eating and exercise habits. What you eat and how you eat changes after surgery, but the benefits of weight loss and your improved health are well worth these efforts.
Risks
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:
- 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 sudden diarrhea, nausea, lightheadedness, stomach cramps and flushing.
- Dehydration. Because you're not supposed to drink fluids with your meals, some people become dehydrated as a result of the gastric bypass diet. You can prevent this by sipping 48 to 64 ounces (1.4 to 1.9 liters) of water or 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 nauseous 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 food can 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.
- Gastric bypass diet and diet progression. University of Virginia Health System. http://www.healthsystem.virginia.edu/internet/surgery/GASTRICBYPASSDIET.doc. Accessed Aug. 10, 2009.
- Barbara Woodward Lips Patient Education Center. Nutritional guidelines for weight-reduction surgery. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2009.
- Bariatric surgery for severe obesity. National Institute on Diabetes and Digestive and Kidney Diseases. http://win.niddk.nih.gov/publications/PDFs/gasurg12.04bw.pdf. Accessed Aug. 10, 2009.
- Mun EC, et al. Surgical management of severe obesity. http://www.uptodate.com/home/index.html. Accessed Aug. 10, 2009.
- Mun EC, et al. Complications of bariatric surgery. http://www.uptodate.com/home/index.html. Accessed Aug. 10, 2009.
