Postoperative diet in stages

The postoperative diet plan is a crucial phase of weight loss surgery. It is when food is introduced into the new stomach in gradual stages, over a period of six to eight weeks. The diet plan plays a vital role in aiding the healing process, kickstarting weight loss and avoiding the risks of internal injuries from ingesting solid food. 

Postoperative diet plans vary for different weight loss surgeries and you will need to follow the diet plan given to you by your surgery provider. Progress is gradual and patience is necessary to complete all the stages without introducing complications. It is helps to keep in mind that you will soon be enjoying a healthy diet with lots of variety, but eating smaller portions that you were previously. Depending on your providers advice, after 6-8 weeks you can begin introducing solid foods to your diet. A portion-controlled diet plan will help you to keep off the excess weight and reach weight loss goals.  

The Stages 

  • Clear liquid for 1-2 days after surgery 
  • Full liquid for 2-4 weeks after surgery 
  • Puree and soft food 4-8 weeks after surgery 
  • Semi-solid food 6-8 weeks after surgery 
  • Solid food after 8 weeks

Clear Liquid

The liquid diet helps keep you hydrated in the vital days immediately after surgery. Although you should still aim to drink the recommended 1.5 litres of water a day by taking small, frequent sips.

  • Water  (small, frequent sips) Sugar-free fruit squash
  • Chicken or vegetable broth  
  • Hot Bovril or Marmite
  • Strained Miso soup
  • Sugar free ice lollies or ice cubes
  • Tea (including herbal)
  • Coffee
  • Sports drinks
  • Fruit juice (smooth)

Full Liquid  

Full liquids include food nutrients which will aid your recovery and help you regain strength. This stage provides 60-70g of protein per day, with vitamins and minerals. You can continue drinking clear liquids, with the addition of dairy milk, nut milks and pureed soups. However, it is still too early to introduce any solid foods at this stage. 

For Gastric Bypass and Gastric Sleeve patients should avoid fruit juice and drinks that are high in sugar, or at least dilute juice with water. 

  • No added sugar fruit squash
  • Fruit juice (smooth)
  • Sugar free ice lollies or ice cubes
  • Protein shakes
  • Milk shakes  
  • Protein powders or milk powders
  • Skimmed or semi skimmed milk
  • Calcium-fortified soy milk
  • Oat milk or coconut milk
  • No added sugar jelly
  • Chicken or vegetable broth
  • Clear strained soup
  • Liquid smoothies (add milk or water for a looser consistency)
  • Protein yogurt (add milk or water for a looser consistency)

Pureed and Soft Food

As you start to recover, foods high in nutrients are gradually introduce back into your diet. It is important that you introduce only one type of new food at a time. During this stage, depending what your aftercare guidelines suggest, most weight loss surgery patients can expect to eat three meals and up to three snacks per day. You can continue with a full liquid diet while carefully introducing pureed and soft foods. 

  • Fat-free cottage cheese
  • soft creamed cheese
  • Creamed soups
  • Smooth peanut butter and other nut butters
  • Smooth yogurt
  • Soft tinned fruit
  • Mashed bananas
  • Silken tofu (soft)
  • Pureed mash potatoes 
  • low sugar milk shakes
  • low sugar Protein drinks
  • Pureed meats and chicken
  • Pureed vegetables

Pureed and soft foods diet tips

  • Getting enough protein into your body is your priority at this point. It is important to make sure you eat enough protein with each meal.
  • Stop eating when full, even if it is only after a bite.
  • Measure your food portions using measuring cups, measuring spoons or food scales and portion control plates.
  • It is helpful to use a blender to puree food and a strainer to separate any solids.
  • Drink water at least 30 minutes before and after meals.
  • Take vitamin and mineral supplements.
  • Limit or exclude calorific drinks which are high in sugar.
  • Control the use of protein shakes and drinks, these should still be mesurered within your portion control
  • Check that you are following the specific dietary guidelines provided by your surgery
  • Introducing semi-solid foods.

During this stage you can gradually add more soft foods into your diet, following a course of 4 to 8 weeks. Surgical wounds are almost healed, but ingesting solid foods can still cause internal complications. For good nutrition, keep to soft foods which are low-calorie and high in nutrients. 

Introducing soft foods, returning to a normal diet

  • Canned tuna or chicken
  • Extra lean mince beef, chicken or turkey
  • Eggs, egg whites or a fat-free, cholesterol-free egg substitute
  • Fresh, ripe fruit
  • Well-cooked vegetables 
  • Low-fat or fat-free cheese
  • Crab sticks or fresh crab meat
  • Fish (be very careful of bones)
  • Cooked beans and lentils and pulses

Semi-solid food diet tips 

Introduce semi-solid foods slowly, taking small bites and chewing well. If an ingredient doesn’t agree with you then you try it again when your digestion is more robust. At each meal, prioritise eating the food high in protein first, before vegetables and fruit.  Your body must get adequate protein each day to heal quickly.

  • Measure your portions and stick to the recommended serving sizes.
  • Stop eating when satisfied, not full and even if it is only after a few bites. 
  • Drink water at least 30 minutes before and after meals.
  • Leave 30 minutes in between drinking fluids and eating to avoid stretching the stomach pouch.
  • Take vitamin and mineral supplements. 
  • Limit or exclude calorific drinks which are high in sugar (see your surgery guidelines).
  • Control the use of protein shakes, dont rely on them for protein alone, seek to include more sourses of natural proteins. 
  • If solid foods are not agreeing with you, then revert to pureed foods.


Please seek and follow the specific guidelines from your bariatric team. Guidelines vary for individual patient needs and surgeries.