Dietary guidelines

Dietary Guidelines

It is vital in a long run for you to make healthy food choices after your weight loss surgery. It will help you achieve the maximum weight loss goals at the same time maintaining your nutritional needs.

A 4 stage diet plan is recommended to patients after alln types of weight loss surgery, including gastric bypass and sleeve gastrectomy operations. We will provide you more specific guidelines in email. For our English speaking customer convenience we offer a free UK based expert bariatric dietitian’s support for 3 months after your surgery.

The liquid stage will long up to 14 days after surgery. The first 4-5 days you will sip clear liquids – water / diluted, no added sugars juice / luke t peppermint or chamomile tea all day long. After the first 4-5 days you can add to your diet nutritious liquids like non fat broth, semi skim milk, sugar free jelly, skim yogurt without bits, clear thin blended soups, tea, decaf coffee, protein shakes.

Remember the necessary amount of liquid for your body is 1.5 – 2 l a day or 30-35ml of liquid on each kg of your body weight. And at least a half of it should be non-caffeine, non-sugar drinks (=water).

Aim to establish your eating schedule and have 3 main meals per day – breakfast (protein rich drink), lunch (1 small cup of soup & 1 small cup of thin yogurt), and dinner (a protein rich drink and or fruit squash), and 2-3 ‘snack’ meals (for ex. a cup of milk,) between 3 main meals. Drink water between all meals.

Avoid sparkling drinks, alcohol, any liquid with bits, fluids with excess sugar and fats – those can make you feel sick or cause rejecting.

Supplements and medications – our bariatric surgeon Dr Olegs Kozlovskis recommends starting vitamin and mineral supplements 2 weeks post bariatric surgery. For the first period all vitamins and minerals can be used in chewable or liquid form, if you find hard to have them in tablets. If you are on other medicines, you may crush them and space out the pills at least 5-10 minutes apart.

After 2 weeks or earlier after the surgery you can move to the next stage of your diet which you should expect to follow up to 2 weeks, depending on your feelings. Listen to your body! All foods at this stage should be of a consistency of thinned mashed potatoes.

Foods to have on this stage – skim milk, blended soups (with skim milk instead of water), blended fruit shakes with or without milk or fat-free yogurt, blended meat in blended cream soups or mashed potatoes, cooked cereal thinned with skim milk, blended beans, mashed potatoes or other vegetables made with skim milk, sugar-free yogurt, blended cottage cheese (fat-free/low fat), pureed fruits.

Foods to avoid – all solid foods, raw vegetables, tough skin on vegetables and fruits (tomatoes, potatoes, also sausages), sweet corn, tomato seeds, red meets, non pureed meet, hard cheese, toast, bread, rusks, nuts.

Beware of high intake of legumes such as chickpeas, lentils, split peas – they absorb lots of fluid in the bowel and can cause discomfort at this stage of diet.

Tips –

  • Use blender or potato masher to puree your food.
  • Aim to have 3 main meals and 2-3 small snack meals per day. Each meal should not exceed the volume of a measuring cup – 180g (6oz).
  • Chew food well, even though it is mashed already.
  • Eat very slowly – plan at least 30 minutes for a meal.
  • If you are very hungry, try to ensure you have the protein part of your meal first.
  • Do not drink while eating and at least 30 minutes before and after your meals.
  • Supplements – follow your doctor’s instructions.
  • You need to ensure your diet contains sufficient nutrients, vitamins and minerals for you to live healthy. A balanced diet will also ensure that the weight you lose is mainly fat, not a muscle mass. Muscle helps you lose weight by boosting your metabolism when you do even the smallest amount of exercise.

You should expect to be on this stage of diet for up to 2 weeks (usually 5-6 weeks after the operation). But again – listen to your body and your stomach! Some people can have this stage earlier, some later. 

Foods to have: Eggs - any type except fried, several types of casseroles, soups, chopped lean meat (except the red one), low-fat cottage cheese, boiled & peeled vegetables, sugar-free low-fat yogurt, fish in a sauce, well-cooked rice, pasta in sauce, mashed beans, chick peas, kidney beans, soft fruit.

Avoid: Any food with tough skin, stringy or fibrous vegetables such as celery, asparagus, sweet corn; fizzy drinks; alcohol – it can irritate the stomach and is high in calories.


  • Add one new food at a time and observe your reaction to it.
  • Eat very slowly and stop eating as soon as you feel full so you don’t stretch the pouch.
  • You can start to introduce more foods and different textures. But still most of foods should still have a soft or mashed texture.
  • Aim to have 3 main meals a day and one of the suggested snacks, if you feel hungry between meals.
  • Use spices to make your meals more interesting and delicious. Avoid hot chilli, Cayenne pepper and similar.
  • Serve your meals on a small plate.
  • The size of portion can increase slightly but you should continue stop eating as soon as you feel full. Eating to quickly may be painful and can make you sick.
  • Remember – 1,5-2 l of fluids daily.

People usually come to the 4th stage 2-3 months after their bariatric surgery.


  • Add one new food at a time and observe your reaction to it.
  • Read labels when shopping for food!
  • Add breads to your diet last. Bread tends to form a ball, which may be hard to get through the new pouch.
  • You can add red meat, raw vegetables, and raw fruits with skins back into your diet as well.
  • Remember to chew all food very well and sip only limited amounts of liquids with meals, if necessary.
  • Take the recommended by your surgeon supplements daily.

Avoid: sugars, deep fried, high calorie, fast foods, carbonated drinks, alcohol.

The consequences of having a poor diet vary. In the short term it may lead to dry or cracked skin or nails or hair loss. In the long term a lack of nutrients can increase the risk of developing several health conditions. It is important to have a balanced diet including all types of foods!

Reduce risk of dumping syndrome and digestive upset

Concentrated sugars and alcohol, greasy foods and overeating can cause a dumping syndrome. It may cause also vomiting and/or diarrhoea, so try to avoid: candies, chocolate, sweetened & carbonated sodas, honey, cakes, ice cream, any alcohol.

It may happen that you do not tolerate some of foods soon after bariatric surgery. Do not worry and try to add these products to your diet later again.

Balanced diet

You will need to learn nutritional values of products to be sure you treat your body with love and responsibility and provide all necessary nutrients to it.

There are five main food groups (many products like milk, beans etc. fit into more than one group), you should have in a balanced diet plan. Here you can find products and approximate amounts of each you should include in your daily diet plan. Great variety of products is the key.

  • Protein foods – about 15% of non diary protein foods should be included in your daily diet plan. Lean meats (chicken, turkey, fish), eggs, low-fat dairy, tofu, legumes. 
  • Fruit and vegetable foods – 30% of your daily amount of food. Provide essential vitamins, minerals, and fiber, and natural sugars. 
  • Dairy foods (milk products) or Alternatives – 15% of your daily amount of food. Provide protein, calcium and vitamin D for bone health. 
  • Breads, cereals and starchy foods (breads, pastas, potatoes, cereals, oatmeal, wheat flour, corn flour, brown rise, also beans, chick peas and lentils) – 30% of your daily amount of food. It is recommended to stick with wholegrain options that provide you complex carbohydrates, fiber, essential nutrients. 
  • Fats and sugars (margarine, oils, sugars, honey) – less than 10% of your daily amount of food. Healthy fats are considered - avocado, nuts, seeds, olive oil, fatty fish (like salmon).  

Limit Processed and Sugary Foods - high-sugar snacks, fried foods, processed foods and snacks. 

We will provide you a more detailed dietary plan and recommendations. 

Conscious & balanced eating is one of the main long term key factors after weight loss surgery. In order to help our patients to break old eating habits and to create new, we offer a 3 months support by an Expert Bariatric Dietitian. 


SEND US YOUR QUESTION, if you wish to discuss bariatric surgery options!