After bariatric surgery you will need to make changes to your eating patterns. The patient's diet after surgery follows a specific progression to help avoid food intolerances and other nutrition complications.  The diet progression is designed to allow you to heal. Initially after surgery the main goal is to meet your fluid and protein needs from a liquid protein diet.  As you get farther out from surgery, the variety of whole foods (low in sugar and fat of course) will increase to better meet your nutrition needs for long term health. It is important that you follow the diet progression to maximize healing and minimize risk for complications.

  • exerciseThe first eight weeks after surgery: in the first eight weeks after surgery, you need to change your eating habits to limit or avoid nausea and vomiting and to promote weight loss.
  • Lifetime success: To maintain a healthy weight and to prevent weight gain, you must develop and keep healthy eating habits. You will need to be aware of the volume of food you can tolerate at one time and make healthy food choices to ensure maximum nutrition from a minimum volume. Exercise must be a part of your daily routine to help prevent weight re-gain.

Swallowing food in chunks can rupture the anastomosis or fill up the small stomach pouch quickly, preventing foods from passing into the intestine, and may lead to vomiting. It is CRITICAL that you eat slowly and chew food well to lower the risk of nausea and vomiting. The following tips may help you eat more slowly.

  • Set aside 30 minutes to eat each meal.
  • Chew your food 20 times with each bite.  Ground or soft foods may be better tolerated, even several months after surgery.
  • Explain to friends and family why you must eat slowly so they will not urge you to eat faster.
  • Take small bites of food (you may want to use a smaller spoon and use a saucer instead of a plate to help you with portion control).
  • Pay attention to taste; learn to savor your food.
  • Stop eating as soon as you are full (over-eating even one ounce could make you vomit).

Feeling of fullness

Learn to recognize when you are full. Indications of fullness may be:

  • Pressure or fullness in the center of your abdomen just below your rib cage.
  • Feelings of nausea, regurgitation or heartburn.

Vomiting or dysphagia (difficulty swallowing)

Vomiting may occur after gastric bypass surgery. It is often the result of eating inappropriately but can be caused by a surgical complication and should be reported to your surgeon.

Vomiting may occur after bariatric surgery. It is often the result of eating too much or too fast at one time.  Vomiting and dysphagia can also be caused by a surgical complication, such as stricture, and should be reported to your surgeon or nurse practitioner.

Eating too much or too fast are the most common causes of vomiting.  Other eating behaviors that may also cause vomiting are:

  • not chewing food properly
  • eating too much food at once
  • eating solid foods too soon after surgery
  • drinking liquids either with meals or right after meals
  • lying down after a meal
  • eating foods that do not agree with you

If you begin vomiting and it continues throughout the day, stop eating solid foods and sip clear liquids (water, broth, caffeine free tea). The vomiting may indicate that the stomach pouch is blocked. If vomiting continues for more than 24 hours, contact your doctor.

healthy diet

It is important to eat foods with good nutritional value. The amount of food you are able to eat at a meal will be reduced. Eating three meals per day will be essential.  Meals should be made up of solid foods. Liquids should be consumed between meals. Each meal should have at least one to two ounces of a protein source (such as eggs, cottage cheese, fish, poultry, beans, meat, and tofu) and a small amount of vegetables.  Fruit may also be eaten with a meal or combined with some protein for a snack (i.e. a few apple slices with 1 ounce low fat cheese).  To keep calories low, limit or avoid added fats and sugars.  Food labels and measuring cups, scales, and spoons will help with portion control.

Avoid frequent snacking. Snacking can add significant calories and keep you from losing weight. Inappropriate snacking can even lead to weight gain. 
The volume you can tolerate will be limited so choose foods wisely to avoid filling up on foods with little nutritional value. Eating foods from each of the five food groups will provide balance. You must get a maximum amount of nutrition from a minimum amount of food.


Drink at least seven cups of liquids per day between meals. Recommended beverages are water, skim milk, and other zero-calorie caffeine free drinks.  Caffeine free or decaf coffee can be reintroduced in small quantities.  

  • Do not drink beverages 20-30 minutes before or after meals. (There is not enough room in your stomach for both food and liquids.)
  • Sip beverages slowly.
  • Avoid drinking from a straw (it is more difficult to control the volume of your intake).
  • Avoid high calorie drinks such as milkshakes, regular soda, beer and other alcoholic beverages. The calories from these drinks can add up quickly if you are sipping on them throughout the day.

Vitamins and minerals

All bariatric patients will be required to take vitamin and mineral supplements daily after surgery.  The number of supplements required depends on the type of surgery and lab results.  All bariatric patients will have specific vitamins and mineral levels checked with an annual blood draw.   See the table below for more details.

X = 1 time per day
XX = 2 times per day

Supplements    Surgery Type  
  Gastric Lap Band Vertical Sleeve Gastric Bypass
Multivitamin with minerals X XX XX
Calcium citrate 500-600 mg XX XX XX
B12 (sublingual) 500 mcg -- X X

Certain foods may be difficult to tolerate

Tolerance to foods after surgery varies from one individual to the next. Once you are back on a more regular diet, through trial and error you may find you are able to tolerate some foods better than others. There may be some foods that your digestive system cannot handle well.

Many things may cause discomfort and vomiting. Sometimes the source may be a specific food. Do not avoid a food just because you vomit once after eating it. You may wish to wait a few days, but you should try that food again. Tolerance to foods may improve with time. ALWAYS be sure to chew foods very well, take small bites and eat slowly.

Detailed information about the post-bariatric surgery diet will be provided at your first visit with the surgeon in clinic.

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