Pre/Post Op guidelines

Pre operative diet

Dr Hruby is happy for you to do any low carbohydrate, low fat diet for approximately a month before surgery. He expects people to lose 3-5kg, or 6-11lb. However, the main reason for doing this is to shrink the liver by reducing or eliminating the stores of glycogen. This makes the liver more pliable during the procedure and can actually reduce the number of incisions made. So the main reason for the pre-op diet is for safety.

If you have a BMI of 40 or over you need to do a pre-op diet of 1 month

35 – 40 two/3 weeks

under 35 a few days of low carb will suffice

 Generally, the choice is;

  • 4 pints of semi-skimmed milk a day, a no added sugar jelly and a low fat
  • Soup eg a weight watchers soup, 4 sticks of sugar free gum.
  • 4 weight watchers soups a day, 4 muller lights a day, and a pint of SS milk.
  • Food, any, as long as it’s low carbohydrate and low fat, staying to about 1200 calories a day.
  • A very low calorie diet made of packs, eg Cambridge Diet, Slim and Save, Celebrity Slim, with a low carb meal in the evening.
  • Atkins type diet, ie very low carb

Vitamins and supplements

Standard supplementation;

Please start taking a good quality multi-vitamin, such as Centrum, Forceval or Sanatogen Gold, at least one month before surgery this is for all bariatric patients for life

Immediately post-op, buy some children’s chewable ones, and take two a day, chewing them to mush. Take these for about a week, then you can return to the tablets, which you must take indefinitely.

Iron, 45–60 mg daily, check multi-vitamin levels, they may be sufficient. Spatone is a kind, well absorbed, non-constipation causing version of iron, or buy the multivitamin with iron.

Biotin, 1000 mcg daily (to hopefully minimise hair loss, isn’t guaranteed to work).

Other supplements sleevers and bypass only:

Sublingual vitamin B12 (under tongue); sleevers only, 100mcg daily, then titrate upwards if blood tests indicate the need or get your GP to give you three monthly injections.

Calcium citrate, 1200 to 1500 mg daily (NOT carbonate as this doesnt absorb into the bloodstream effectively) with D3. At least 3000 international units of vitamin D3. These need to be spread out over the day, 3 times a day as you can only absorb 500 mg at one time.

Pregnancy after Wrap/Sleeve Surgery; vitamin regime

The chances of a miscarriage are significantly higher for women who have had wls within the last year. One year post surgery apparently there is no higher risk than the general population. In pregnancies even after one year in addition your usual multi-vitamin; taking high levels (prescription only) 5mgs of folic acid and an additional Vitamin D tablet as after wls your body finds it harder to absorb essential pregnancy vitamins. I hope this is useful info to anyone hoping to get pregnant.

If you’re feeling a bit under the weather, go to your GP and ask for a post-bariatric blood test. The standard test may not cover what is required testing for bariatric patients, so print this off and take with you;

Post-Operative Blood Monitoring For All Bariatric Surgery Patients the following blood tests should be checked pre-operatively and every 3-6 months in the first year post-operatively, and at least annually thereafter*:

  • Full blood count
  • Electrolytes: sodium, potassium, urea, creatinine, phosphate, magnesium
  • Glucose
  • Liver function test
  • Iron
  • Ferritin
  • Vitamin B12
  • Folate / red cell folate
  • Lipid profile: total cholesterol, LDL, HDL, triglycerides
  • 25-Hydroxyvitamin D
  • Calcium
  • Parathyroid hormone

Optional blood tests: Vitamins A and E, zinc, selenium, copper* If any results abnormal at 12 months will need to continue 3 monthly monitoring until within normal range

Post-operative diet following sleeve gastric resection, gastric plication and gastric bypass (written by Panochova Hospital dietitian)

The post-operative regimen requires a strict diet to be maintained in order to avoid a number of complications.

In the first three weeks a strictly liquid diet is required; the consistency of the food must be no thicker than that of yogurt milk. Emphasis on consuming the food very carefully, swallowing after each sip with 3-5-minute breaks in between. The same regimen also applies with drinks, so it can be said with some exaggeration that in the first 2-3 weeks,the patient must learn to just sip at food all day.

The food should be mixed and diluted with skimmed (low-fat) milk, broth, juice.

Examples of liquid food – broth, tea,non-sparkling unsweetened drinks, fruit and vegetable juices, soups, yogurts diluted with low-fat milk.

During the next two weeks the consistency of the food is thickened to mushy (yogurts, snacks, semolina pudding,…).

Suitable foods are: Protein-rich: mixed meats (fish, poultry, pork,..), eggs, dairy products (low-fat fresh cottage cheese, skimmed milk, unsweetened, low-fat yogurts…) Foods other than protein-rich foods can also be eaten: apple juice, banana, potatoes, fruit and vegetables with no seeds or hard skins, sugar-free pudding, gelatine…

After 5 weeks  patients can try standard meals,although with a preference for more delicate foods that can be chewed completely. As a result, the daily diet is then divided up into around 5-6 or 7 small doses, the volume of which should not exceed 100ml(g).

You will need to suddenly cut down on the amount you eat!

Suitable: High-protein foods – fish (if tinned, in own juice, not in oil), non-fatty lean beef and pork. The meat should be boiled, roasted or grilled. Beans, soya and pulses, eggs and egg white, skimmed, low-fat and semi-skimmed milk (1% fat) and dairy products, tofu, unsweetened and low-fat yogurts. Fruit and vegetables are also suitable (tinned, unsweetened or fresh, frozen and cooked).

Drinking regimen

Take care to drink regularly, ideally around 2-3 litres throughout the day, drinking at 10-minute intervals to ensure that the body gets enough liquids and does not get dehydrated when the weather is warm. Ideally avoid drinks that are sparkling or sweetened.Suitable: Water, tea, fruit and vegetable juices, non-sparkling mineral water.

Because of the minimum amount of food the body needs, it is recommended to supplement your diet with multi-vitamin preparations containing trace elements to prevent deficiency disease.

Following a gastric bypass it is essential to takes substitutes for vitamins and trace elements, particularly vitamin B12 and iron.

You might find some foods hard to eat.

You will have to chew your food more carefully and thoroughly than before the operation.

Initially some people continue to have difficulties with meat, hard, sticky rice, bread, rolls and pastries (these should be avoided anyhow because of the high carb content), which form a sticky paste when moistened.

Remember!  Even after the operation there is no quick solution to obesity and your weight-loss depends solely on your ability to follow recommendations concerning diet and exercise.

WLS rules and behaviour modification guidelines

  • Nothing you can chew for 2 hours following a meal
  • Nothing to drink for half an hour (at least) following a meal
  • Protein then veg then carbs -If not finished at 20mins, STOP
  • AVOID drinks with calories
  • Choose solid food over soft/liquid food
  • 100g or 1 cup size of food per meal
  • 70+gm protein per day
  • At least half of every meal should be protein and EAT PROTEIN FIRST
  • 2 litres of fluid per day
  • EXERCISE for 30 min a day minimum
  • Fork down between bites
  • Side plate for your meal
  • No straws or gum, they allow too much air into your stomach
  • No fizzy EVER (if you have to, stir vigorously to get rid of the bubbles, water down with ice, and leave the lid off overnight)
  • If you don’t tolerate a food the first time, wait a week and try again
  • Protein drinks to boost your protein
  • Chew all fibre-containing foods very well
  • Keep a food and exercise diary
  • Don’t eat after 7pm.
  • Don’t eat carbs that don’t grow.


  • Don’t eat in front of the TV.
  • Don’t read while eating.
  • Pre-portion your food and put the box or package away.
  • Keep tempting foods out of the house.
  • Don’t go to the grocery store hungry.
  • Make a shopping list.
  • Use smaller plates and bowls.
  • Keep healthy foods available.
  • Focus on activities other than eating.
  • Brush your teeth after meals or if feeling the desire to eat.
  • Don’t eat standing up at parties or buffets.
  • Don’t stand at the food table at the parties.
  • Offer to bring a healthy food item to a party.
  • Park your car far away from your destination.
  • Get up to change the TV channel instead of using the remote control.
  • Take the stairs instead of the elevator.
  • Keep a food and exercise diary.

Example menu

Liquid mushy food

Breakfast: (maximum 80-100ml) yogurt milk

Elevenses:  (maximum 80-100ml)diluted fruit puree

Lunch: (maximum 80-100ml) creamy soup with no solid pieces

Snack: (maximum 80-100ml) diluted vegetable puree

Dinner: (maximum 80-100ml) skimmed or semi-skimmed milk

Supper: (maximum 80-100ml) (2 spoons)blended cooked meat diluted with broth

Mushy food

 Breakfast: (maximum 80-100ml) yogurt milk

Elevenses: (maximum 80-100ml) fruit puree

Lunch: (maximum 80-100ml) (2-3 spoons) mashed potato

Snack: (maximum 80-100ml) vegetable puree

Dinner: (maximum 80-100ml) (2 spoons) blended cooked meat diluted with broth

Supper: (maximum 80-100ml) skimmed or semi-skimmed milk

Solid food – cut down considerably on carbs in this stage (less than 50g per day)

1st day

Breakfast: half a slice of bread(20-25g), 1-2 slices (20-50g) of lean boiled ham

Elevenses: 100ml yogurt

Lunch: 100ml (2-3 spoons) mashed potato

Snack: 100ml (2-3 spoons) stewed fruit

Dinner: 100g (2-3 mouthful) steamed fish fillet

Supper: 100g 3-4 slices of Edam cheese 30% fat in dry matter

2nd day

Breakfast: oatcakes (20-25g), 20-30g cheese

Elevenses: 100g latte coffee

Lunch: 100ml thick soup

Snack: 100g (2-3 spoons) tomato and egg salad

Dinner: 100ml (2-3 mouthful) blended boiled chicken

Supper: 100ml cottage cheese up to 20% fat in dry matter

3rd day

 Breakfast: 100g porridge make with milk

Elevenses: 100ml yogurt

Lunch: 20g wholewheat spaghetti, 70g (2-3 spoons)Bolognese sauce

Snack: protein shake

Dinner: 100g ( 3-4 mouthful) grilled fish

Supper: low sugar hot chocolate

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Possible Complications

It is important that we are fully aware when entering into Weight Loss Surgery

Risks, complications and long-term issues following Weight Loss Surgery

As with any major surgery, weight-loss surgeries pose potential health risks, both in the short term and long term.

Risks associated with the surgical procedure can include:

  • Excessive bleeding
  • Infection
  • Adverse reactions to anaesthesia
  • Blood clots
  • Lung or breathing problems
  • Leaks in your gastrointestinal system
  • Death (rare)

Longer term risks and complications of weight-loss surgery vary depending on the type of surgery. They can include:

  • Bowel obstruction
  • Dumping syndrome, causing diarrhoea, nausea or vomiting
  • Gallstones
  • Hernias
  • Low blood sugar (hypoglycaemia)
  • Malnutrition
  • Stomach perforation
  • Ulcers
  • Vomiting
  • Death

When weight-loss surgery doesn’t work

It’s possible to not lose enough weight or to regain weight after any type of weight-loss surgery, even if the procedure itself works correctly. This weight gain can happen if you don’t follow the recommended lifestyle changes. To help avoid regaining weight, you must make permanent healthy changes in your diet and get regular physical activity and exercise. If you frequently snack on high-calorie foods, for instance, you may have inadequate weight loss, or even regain a large percentage of your original loss. Your first year following surgery is very important as this is the time to learn new, healthy habits, so that when maintenance arrives, it is not so difficult to contend with. Please make the most of your ‘golden time’.

Bariatric surgery is NOT the ultimate solution to your weight issues, but in combination with a healthy lifestyle, it is a great tool. It’s up to you how you use it!

To help prevent regain you have to

Learn how and what to eat all over again eg no snacking, stay away from cake, crisps,chocolate, junk-food, take-aways, alcohol, fizzy drinks (fizzy drinks are the quickest way to regain your hard-earned weight loss), minimise carbohydrate based foods (rice, pasta, white bread, potatoes), and eat more healthy foods(meat, fish, vegetables, fruit). Also you MUST start an exercise regime that you can stick to permanently.

If you feel that you cannot/will not do these things, you are NOT ready to have weight loss surgery, and you will have a high chance of regain.

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