07 January 2021


Section 4a: Before surgery – liver shrinkage and the preoperative diet


Section 4a: Before surgery – liver shrinkage and the preoperative diet  

Why do I need to follow a pre-op diet? 

The pre-op diet is required in order to shrink your liver, which allows your surgeon to operate more easily and safely. The diet achieves this by containing a maximum of 100g of carbohydrate and 1000kcal (calories) per day, which forces the stores of glycogen (carbohydrate) in your liver to reduce. 

You may also need to lose a certain amount of weight before surgery, either by the request of your surgeon/consulting practitioner or to qualify for admission to a certain hospital. The diet will also assist with achieving this. 

If you fail to follow this diet, you run the risk of having your procedure cancelled or abandoned, and the cost of procedure cannot be refunded. Do not be tempted to have a special meal or larger meal before surgery, as this will reverse the liver-reducing effects of the diet. 

Do I need to speak to a dietitian before the surgery? 

Yes. Your Surgeon Assistant will arrange a preoperative consultation (face-to-face or telephone) with the dietitian to discuss the pre-operative diet and the short- and long-term post-operative dietary guidelines which are crucial for success. You will receive an email confirming the date and time. It is imperative that you keep this appointment; if you are unsure of when your appointment is, please contact your Surgeon Assistant. 

How long do I need to follow a pre- operative diet for? 

This depends on your BMI: 

BMI (kg/m2) 

Length of pre-operative diet 

50 or above 

2-4 weeks 

40-49.9  

At least 2 weeks 

35-39.9  

At least 1 week 

30-34.9  

 

Generally no specific preoperative diet is required. However, we would 

strongly recommend that you follow a healthy low fat eating plan before 

surgery and follow this plan for 2-3 days prior to surgery. 

 Please note this is just a guide and your surgeon or consulting practitioner may advise differently. You should always follow their advice.  

What if I have diabetes? 

If you have diabetes and are treated with insulin, liraglutide (Victoza), exenatide or a sulphonylurea tablet (glicazideglibenclamidetolbutamide, glimepiride, glipizide), you may need to adjust the dose of your insulin or medication. Please contact your Diabetes Specialist Nurse / Practice Nurse / GP before starting the pre-operative diet. 

Do I need to take any supplements during the pre-operative diet? 

It is recommended you take a multivitamin and mineral supplement for the duration of the pre-operative diet, as it will vastly reduce your intake. Any brand is suitable providing it is complete – it must contain vitamins and minerals. Good quality off-the-shelf varieties include: 

  • SanatogenComplete A-Z 
  • Tesco A-Z Multivitamins and Minerals
  • Lloyd’s Pharmacy A-Z Multivitamins and Minerals
  • Superdrug A-Z Multivitamins and Minerals

A variety called Forceval is also available on prescription or over-the-counter. It is also available in a soluble form, so can be used in the initial period after surgery when solid tablets are not to be taken. 

Does the pre-operative diet have any side-effects? 

You may become dehydrated and constipated as a result of the reduced carbohydrate in the pre-op diet, and so you will need to drink at least 2 litres of additional fluid per day. 

 Suitable fluids include water, ‘no added sugar’, ‘sugar free’ or ‘diet’ flavoured water/squash/cordial/fizzy drinks, tea (including fruit/herbal varieties) and coffee. Any milk should be taken from the allowance given in the plan you choose. No sugar is allowed, but you can use any type of artificial sweetener. Caffeinated drinks can also be includedIf you wish to have a savoury drink, you may have an Oxo or Bovril. 

This dramatic change in dietary habits can also cause other unpleasant side-effects including lower energy levels, headaches, mental dullness, temporary dizziness, nausea, diarrhoea, sluggish mobility and bad breath (you can have sugar-free chewing gum to help with this). 

What are the options for the pre-operative diet? 

There are 3 options: 

  1. Option 1 is based on liquids (milk or meal replacement drinks) and yogurts
  2. Option 2 is based on solid food, with a vegetarian option available
  3. Option 3 is a mixture of the two above 

 

Option 1:  Liquids (milk or meal replacement drinks) and yogurts 

 

STEP ONE

  • Choose your milk or meal replacement from the first column of table 1

STEP TWO

  • The second column of table 1 tells you how much milk or how many meal replacements you can have per day

STEP THREE

  • Choose 1 yogurt or 1 portion of milk to have in addition per day from table 2 

Table 1 

Milk 

Amount (ml) 

All cows milk (including lactose free) but NOT whole milk 

1800 

Soya milk (sweetened) or soya light milk 

2000 

Meal replacement drinks 

Number of portions per day 

Asda Great Shape  

4 

Celebrity Slim – shakes made from powder, smoothies or soups (vegan options available) 

3 

Lighterlife fast shakes 

4 

Slim Fast Advanced Vitality – shakes made from powder  

3 

Slim Fast Advanced Vitality – ready made shakes /  vegan shakes made from powder 

4 

Slim Fast – ready made shakes 

4 

Tesco Slim  

4 

Please make up the meal replacements as instructed by the manufacturer.  

Table 2 

200ml All cows milk (including lactose free) but NOT whole milk 

250ml Soya milk (sweetened) or soya light milk 

125g Activia 0% Blueberry / Cherry / Peach / Plain / Raspberry / Strawberry / Vanilla 

115g Danone Light and Free Greek Style Yogurt Blueberry / Cherry / Coconut / Lemon / Passion Fruit Peach / Raspberry / Strawberry 

120g Muller Light Greek Style Cherry / Coconut & Vanilla / Lemon / Mango / Raspberry / Strawberry 

90g Weight Watchers Fromage Frais Apricot / Blackberry / Cherry / Forest Fruits / Peach / Raspberry / Strawberry  

200g Alpro plain 

If you find a yogurt that is not listed, it must provide a minimum of 5g protein and no more than 110kcal and 10g carbohydrate per portion. 

Please note regarding meal replacement products: If you want to use a meal replacement product that is not listed, please speak with your dietitian before doing so, as many are not suitable for the pre-operative diet.  

 

Option 2: Solid food 

 

This plan consists of food which you can incorporate into your day as you wish. If you do not eat meat or fish, there is a vegetarian option available – please ask your dietitian in your preoperative appointment for a copy of this.  

 All food must be weighed using digital kitchen scales. IMPORTANT: The weighing of food is crucial to ensure accuracy. Do not estimate anything. If you feel you will not be able to do this, we would strongly recommend that you follow Option 1 or 3 instead as they require less weighing and measuring. Please note that the weights given are the maximum allowed, but you do not have to have the full amount. 

 

Number of Portions Allowed 

 

The table below shows how many portions of each food group you are allowed per day. 

Food group 

Number of portions 

Carbohydrate 

3 

Protein 

2 

Vegetables/salad/beans/pulses 

4 

Fruit 

2 

Milk/yogurt  

2 

 

If there are any foods not listed that you would like to include, please mention this to the dietitian. If nutritional information for the food/product is available, they can work out the portion size in grammes. 

 

Carbohydrate – 3 per day

 

Food 

1 portion (g) 

Food 

1 portion (g) 

Bread/pitta bread 

20 

Pasta, boiled 

40 

Couscous, plain, cooked 

40 

Pasta / rice, uncooked  

10 

Couscous, plain, uncooked  

10 

Plain non sugary cereal 

10 

Crumpets 

20 

Rice, boiled 

30 

Egg noodles, boiled 

70 

Rye crispbread 

10 

New potatoes, boiled 

60 

Sweet potato, boiled  

40 

Old potatoes, boiled/baked, without skin 

50 

Wrap 

20 

 NOTE: 1 carbohydrate portion equates to 2 vegetable/salad/beans/pulses portions, if you wish to swap to these instead. If you are choosing gluten free alternatives, the portion size is the same as the gluten-containing food listed above. Weights of wholemeal/brown options are the same.  

 

Protein – 2 per day 

 

Food 

1 portion (g) 

Food 

1 portion (g) 

Beef mince, extra lean, 5% fat, stewed  

110 

Pork, fillet, fried (spray oil)  

100 

Cheddar cheese, half-fat 

70 

Prawns, boiled  

180 

Chicken roasted/grilled, without skin 

90 

Salmon, pink, canned in brine, drained  

120 

Cod, poached, drained 

200 

Tuna, canned in brine/mineral water, drained 

180 

Ham, honey roast/breaded 

160 

Turkey mince, stewed 

130 

 

Vegetables/salad/beans/pulses – 4 per day 

 

Food 

1 portion (g) 

Food 

1 portion (g) 

Baked beans, regular 

30 

Lettuce 

210 

Beetroot, pickled 

80 

Mushrooms, raw 

230 

Broccoli, boiled 

70 

Onions, raw 

60 

Broccoli/cauliflower, raw 

80 

Pea (frozen), boiled  

40 

Carrots/cauliflower, boiled 

100 

Quinoa, uncooked  

20 

Celery, raw 

500 

Red kidney beans, canned 

20 

Cucumber 

300 

Spinach, boiled/raw 

120 

Green beans, boiled 

100 

Sweetcorn, kernels, canned, drained  

20 

Leeks, boiled 

140 

Tomatoes, raw 

150 

Lentils, boiled 

20 

Turnip, boiled 

250 

 

Fruit – 2 per day

 

Fruit 

1 portion (g) 

Fruit 

1 portion (g) 

Apples, raw 

80 

Oranges  

110 

Bananas 

40 

Pears, raw  

100 

Blueberries 

120 

Pineapple 

90 

Grapefruit 

140 

Raisins 

10 

Grapes 

60 

Strawberries 

160 

Melon, galia/honeydew 

150 

Watermelon 

140 

All weights of the fruits are of the edible components, i.e. no peel or inedible skin.

 

Milk/yogurt – 2 per day

 

200ml All cows milk (including lactose free) but NOT whole milk 

250ml Soya milk (sweetened) or soya light milk 

125g Activia 0% Blueberry / Cherry / Peach / Plain / Raspberry / Strawberry / Vanilla 

115g Danone Light and Free Greek Style Yogurt Blueberry / Cherry / Coconut / Lemon / Passion Fruit Peach / Raspberry / Strawberry 

120g Muller Light Greek Style Cherry / Coconut & Vanilla / Lemon / Mango / Raspberry / Strawberry 

90g Weight Watchers Fromage Frais Apricot / Blackberry / Cherry / Forest Fruits / Peach / Raspberry / Strawberry  

200g Alpro plain 

 

Drinks: At least 2 litres of fluid per day, as described earlier on in this section. If you are having tea or coffee, you will need to use milk from the allowance above. 

Alternatives: The dietitian will be able to provide you with a comprehensive list of alternatives if you do not like some of the listed foods. If you wish to have the vegetarian option, please ask your dietitian.  

Seasonings/flavourings/additions: You may use any fresh or dried herbs or spices (including chilli) to flavour your meals.

Do not use any oil, butter, spread/margarine, cream or ready-made sauces (including salad dressings, mayonnaise & salad cream).  

You can of course make your own sauces using allowances above. You may also use up to 100ml daily of any type of vinegar. You may use up to 5 sprays of 1kcal per spray oil per meal if required. 

 

Sample plan 

 

We have created a sample plan for three days to show how you might put your allowances together. 

 

Day 1 

Day 2 

Day 3 

Breakfast 

20g crumpets 

160g strawberries 

1 yoghurt from list 

10g plain unsweetened cereal with milk from allowance 

150g fresh melon 

20g bread 

140g watermelon 

1 yogurt from list 

Lunch 

Rice salad: 

30g boiled rice  

180g tuna (in water) 

20g sweetcorn 

150g chopped tomatoes 

Herbs and a splash of balsamic vinegar to flavour 

20g pitta bread  

160g honey roast ham 

Salad made from: 

150g cherry tomatoes 

210g lettuce 

300g cucumber 

(Serve half at lunch and half with dinner) 

 

10g rye crispbread with: 

70g grated half fat cheddar 

60g chopped onion and 

80g pickled beetroot 

Dinner 

Roast dinner: 

40g boiled sweet potato 

90g roast chicken (no skin), spices to flavour 

100g boiled green beans and 100g boiled cauliflower 

50g baked potato (no skin) with 70g grated half-fat cheddar and 30g baked beans. 

 

Serve with remaining salad from lunch 

 

Chinese prawn fakeaway: 

70g boiled egg noodles  mixed with 180g boiled prawns 

100g of carrot batons and 

80g broccoli florets stir-fried in up to 5 sprays of Frylight. Add chilli and ginger to taste. 

Snacks 

60g grapes 

1 fresh pear 

1 pot of yogurt from list 

120g blueberries 

Additional milk 

200ml semi or skimmed milk for drinks 

200ml semi or skimmed milk for drinks 

200ml semi or skimmed milk for drinks 

Drinks 

Drinks: drink at least 2 litres of fluid as described in your Patient Information Booklet 

Drinks: drink at least 2 litres of fluid as described in your Patient Information Booklet 

Drinks: drink at least 2 litres of fluid as described in your Patient Information Booklet 

 

Option 3: Milk or meal replacement drinks with solid food

 

This plan consists of meal replacement shakes or milk and some food which you can incorporate into your day as you wish. If you do not eat meat or fish, a vegetarian option is available – please ask your dietitian in your preoperative appointment for a copy of this.  

This plan involves less weighing and measuring than Option 2, yet still allows some solid food unlike Option 1. As such, you may find it easier and more practical to follow. 

 

1. Milk or meal replacement drinks

 

Firstly, decide what milk or meal replacements you are going to have each day.  

 

Table 3 

Milk 

Amount (ml) 

All cows milk (including lactose free) but NOT whole milk 

1100 

Soya milk (sweetened) or soya light milk 

1300 

Meal replacement drinks 

Number of portions per day 

Asda Great Shape  

2 

Celebrity Slim – shakes made from powder, smoothies or soups (vegan options available) 

2 

Lighterlife fast shakes 

2 

Slim Fast Advanced Vitality – shakes made from powder  

2 

Slim Fast Advanced Vitality – ready made shakes /  vegan shakes made from powder 

2 

Slim Fast – ready made shakes 

2 

Tesco Slim  

2 

 

Please make up the meal replacements as instructed by the manufacturer.  

 

2. Solid food

 

Then choose what food you are going to have each day. The table below shows how many portions of each food group you are allowed per day. 

 

Food group 

Number of portions 

Carbohydrate 

1 

Protein 

1 

Vegetables/salad/beans/pulses 

2 

Fruit 

1 

Milk / yogurt  

1 

 

Please refer to option 2 earlier in this section for the suitable foods in each group. 

If you prefer to follow the vegetarian option, there are two ways you can do this. You can exclude the milk/yogurt portion and have the following portions of each food group per day:  

 

Food group 

Number of portions 

Carbohydrate 

1 

Protein 

2 

Vegetables/salad/beans/pulses 

2 

Fruit 

1 

 

Or you can exclude the carbohydrate and fruit portions and have the following portions of each food group per day: 

 

Food group 

Number of portions 

Protein 

2 

Vegetables/salad/beans/pulses 

2 

Milk / yogurt  

1 

Please ask your dietitian for the list of vegetarian foods.  

If there are any foods not listed that you would like to include, please mention this to the dietitian. If nutritional information for the food/product is available, they can work out the portion size in grammes. 

Drinks: At least 2 litres of fluid as described earlier on in this section. If you are having tea or coffee, you will need to use milk from the allowance above. 

Alternatives: The dietitian will be able to provide you with a comprehensive list of alternatives if you do not like some of the listed foods. If you wish to have the vegetarian option, please ask your dietitian.  

Seasonings/flavourings/additions: You may use any fresh or dried herbs or spices (including chilli) to flavour your meals. 

Do not use any oil, butter, spread/margarine, cream or ready-made sauces (including salad dressings, mayonnaise and salad cream). You can of course make your own sauces using allowances above. You may also use up to 100ml daily of any type of vinegar. You may use up to 5 sprays of 1kcal per spray oil per meal if required. 

All the information above is correct at time of production 

 

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