Weight Loss Surgery Expectations After Diet

Bariatric surgery drastically reduces the size of the stomach and, therefore, the amount of food the stomach can hold. After bariatric surgery, stomach capacity is reduced to a few tablespoons of food. The stomach eventually expands until it can contain a cup of food, but in the initial months after surgery, stomach capacity is very limited.

This is, of course, the point of bariatric surgery: to reduce the size of the stomach and promote weight loss.

Progressive Diet after Bariatric Surgery

A post bariatric surgery diet basically progresses in three stages: liquids, pureed foods, soft foods. Approximately three months after surgery, solid foods can be reintroduced.

Liquids and semi-liquids are the first foods introduced after bariatric surgery. Liquids are served at room temperature and include:

  • cooked cereals
  • broths
  • juice
  • milk.

The liquid stage of post bariatric diets lasts anywhere from three days to three months, depending on the individual and the type of bariatric surgery performed.

Pureed foods are the next stage of the bariatric surgery diet. Purees include:

  • baby food
  • eggs
  • hummus
  • low fat cottage cheese
  • tofu
  • unflavored cooked oatmeal.

The puree stage of a bariatric surgery diet can last anywhere from three to six weeks.

Soft foods, the next stage, include:

  • ground, finely diced or canned meat
  • soft cooked vegetables
  • soft fresh fruit.

After approximately eight weeks of soft food, most people make the transition to regular, solid food.

The post-diet of those who undergo bariatric surgery also changes in the months following the surgery. Initially, since the stomach is drastically smaller, up to six small meals a day can be required.

Eventually, six small meals are reduced to four, then changed to a regular three meal schedule with three healthy snacks between meals. Food portions are gradually increased to a cup of food at each meal.

Tips for Adjusting to a Bariatric Surgery Diet

Adjusting to a new diet after bariatric surgery takes time and effort. Doctors and dieticians help make the transition as easy as possible. Here are some tips to help make the transition to a post bariatric surgery diet easier:

  • Chew slowly: Chewing food properly after bariatric surgery reduces the risk of food blocking the new, smaller stomach opening.
  • Drink between meals: Drinking with meals increases the risk of abdominal cramps and fills you up faster, preventing you from receiving the nutrients you need from your new diet.
  • Eat slowly: Small meals should take at least thirty minutes to eat. A cup of liquid should be sipped slowly over the course of an hour.
  • Introduce food slowly: Add new foods one at a time to see if they cause stomach pain or nausea.
  • Stop eating before you feel full: The stomach takes time to signal fullness to the brain. If you eat until you feel full, you can overfill your newly reduced stomach. Nausea, vomiting and painful stomach cramps can result from overfilling your new stomach.

Multivitamins and the Bariatric Surgery Diet

Because the stomach absorbs vitamins and minerals less effectively after bariatric surgery, diet after surgery must be supplemented with multivitamins.

Depending on the individual, post bariatric surgery diets may require supplements of:

  • calcium
  • iron
  • multivitamin and/or multimineral supplements
  • vitamin B.

Vitamin and mineral deficiencies can result if supplements are not taken on a regular basis.

Dumping Syndrome

Dumping syndrome, a common complication of bariatric surgery, occurs when the individual eats too much too fast or eats too much food that is high in sugars and fats. With dumping syndrome, the patient’s reduced stomach size is insufficient for the sudden influx of food, and the food is passed into the duodenum too quickly. The result is a set of alarming symptoms that include dizziness, diarrhea and rapid heartbeat.

While distressing and extremely uncomfortable, dumping syndrome is not a threat to health after bariatric surgery. In fact, some believe dumping syndrome has positive effects: The pain and distress associated with the symptom can motivate people to avoid unhealthy foods and stick to their bariatric surgery diets.

Losing Weight with a Bariatric Surgery Diet

Bariatric surgery alone is not enough to ensure weight loss. People who avoid exercise and fail to follow post bariatric surgery diets may lose weight initially but regain weight as their stomachs expand.

In contrast, people who follow a bariatric surgery diet and take regular exercise can expect to lose 50 to 60 percent of extra weight within two years of surgery.


Bariatric Learning Center (n.d.). Foods and diet after bariatric surgery. Retrieved April 17, 2008, from the Bariatric Learning Center Web site.

Mayo Foundation (October 14, 2005). Gastric bypass diet: Nutritional needs after weight-loss surgery. Retrieved April 17, 2008, from the CNN Web site.

Rush University Medical Center (n.d.). Diet after gastric bypass surgery. Retrieved April 17, 2008, from the Rush University Medical Center Web site.