Food after bariatric surgery - Mealsizer®

For you to stay healthy and get lasting results from your gastric bypass or gastric sleeve surgery, good eating habits are important. The first few weeks after surgery, the stomach is very sensitive. Follow the dietary advice you have received from your clinic regarding liquid- and soft-foods. After a few weeks you will eat regular food in small portions evenly distributed throughout the day. You need to eat 5-6 meals during the day, 3 main meals and 2-3 snacks. Never skip a meal.

Portion size
It is very individual how big a normal portion will be for you after a few months, also the fat content in the meal matters for the portion size. It is very important that you listen to your body’s signals and stop eating as soon as you feel saturation. Too much food can cause discomfort, so-called dumping, see below.

Eat slowly and chew your food
The task of the stomach is to decompose and process what we eat. After a gastric bypass or gastric sleeve operation, the processing of the food doesn’t work as well as before. To facilitate the work of the stomach, you need to chew the food more than usual. Divide the food into smaller pieces and eat slowly. If you can stretch out the meal to approximately 20 minutes, this is good.

Most people get the advice not to drink together with food for the first two months. Instead, you can drink right before the meal or wait half an hour after a meal. However, there are no studies showing that you gain weight from drinking together with your meal. If you are bothered by dumping when drinking together with your meal, then just drink less. The body needs about 1.5 litres of fluid per day. Drink slowly and avoid drinks that contain sugar. If you are bothered by the carbonic acid in mineral water, you can pour a glass and leave it for a while.

Dumping is a symptom that can occur if you eat too fast or too much. Calorie-rich foods, both sugar-rich and high-fat foods, can cause dumping symptoms. Foods such as ice cream, cakes, fast food, fatty sauces often cause dumping. You may feel nauseated, tired, cold-sweaty and get palpitations. Dumping is not dangerous but very uncomfortable.

Even if you choose nutritious foods, it is difficult to get sufficient amounts of certain vitamins and minerals. To be sure you get a sufficient nutritional intake, you need to take supplements. Follow the instructions you received from your clinic.

Prevent constipation
The stomach can easily become constipated after bariatric surgery. Prevent constipation by eating whole grains, fruits, vegetables and drinking water. Drink at least half a glass of water every two hours. Prune puree or whey can help soften the intestinal contents. Do not forget to move, exercise facilitates the work of the stomach.

Food choices
It is difficult to consume the amount of nutrients that your body needs after bariatric surgery. Therefore, it is extra important to choose foods that are high in protein, have good fat quality and contain a lot of vitamins and minerals.


  • Eat protein-rich foods in every meal, preferably in snacks/in-between meals.
  • Good sources of protein are pure meat, fish, chicken, turkey, quorn, soy products, eggs, milk, yogurt, cottage cheese and quark.
  • Choose meats with healthier or less fat, cheese with 17% fat and light and medium fat products of milk and yogurt.
  • Use lactose-free milk products if you are sensitive to lactose.

Whole grains

    • Mainly choose bread, cereal, grain and pasta of whole grains and products with high whole grain content.
    • Whole grain products are rich in vitamins, minerals and fiber.

Fruit & vegetables

Eat fruits and vegetables every day.

  • Fruits and berries are great for breakfast and snacks.
  • Peel apple and pears the first month.
  • Vary and eat different kinds of vegetables and root vegetables.
  • It doesn´t matter if you eat cooked, woked, oven baked or raw vegetables. Nothing is better or worse, choose what you like the most.
  • Raw vegetables may need to be chewed extra.
  • It is common to not tolerate some hard-to-digest fruits and vegetables in the first months, see below.


  • You need a small amount of good quality fat every day.
  • Use light margarine on bread and fry in liquid margarine, or any vegetable oil, e.g. rapeseed oil.
  • Drop some oil or vinegar dressing on the vegetables and preferably eat fatty fish and avocado.

Caution with some foods

Some foods may be difficult to digest in the first few months after surgery. This applies to threaded and doughy foods. Examples of foods that can be difficult to digest are nuts, almonds, coconut, popcorn, chips, tacos, white bread, sticky rice, citrus fruits, asparagus, broccoli stalks, rhubarb, pineapple, corn, peas and preserved mushrooms.

NOTE! You have received specific advice from your clinic on how to eat and what to avoid during the first two months. The advice in this information is valid after these first two months.

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Reviewed by: Malin Bruto, leg. dietician with specialist expertise in obesity surgery, Metabolic Center, Carlanderska Hospital, Gothenburg, Sweden

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