Liver shrinkage diet for Bariatric Surgery

Introduction

What is the purpose of a liver shrinkage diet?

A liver shrinkage diet (LRD) is a low-energy (calorie) diet that is particularly low in carbohydrate and fat.

By following a liver shrinkage diet, your body will use up stored carbohydrate (glycogen) from the liver. As the glycogen and some water leave the liver, the liver will shrink and become softer, more flexible and easier to move during surgery.

During laparoscopic (keyhole) surgery, the liver has to be lifted out of the way to access the stomach lying beneath it. Most people needing bariatric surgery have a large, fatty liver, which can make keyhole surgery more difficult.

A large, fatty liver makes it harder for the surgeon to see and gain access to the stomach underneath. This can increase the duration of your surgery and therefore your time under general anaesthetic.

It can also be dangerous, as your liver could bleed heavily during surgery or there could be injury to other organs. If this happens, the surgeon may have to perform open surgery instead of keyhole surgery.

If you do not follow the liver shrinkage diet and your liver has not shrunk, surgery may be considered unsafe and the surgeon may cancel the surgery on the day.

How long will I have to follow the liver shrinkage diet?

The duration of the diet is based on the criteria below:

Criteria	Duration
BMI is lower than 50 kg/m²	2 weeks
BMI is greater than 50 kg/m² and/or you have additional comorbidities, e.g. type 2 diabetes, sleep apnoea or non-alcoholic fatty liver	4 weeks

BMI: body mass index (kg/m²)

What are the liver shrinkage diet options?

• Option 1: SlimFast meal replacement diet
• Option 2: Milk and yoghurt diet
• Option 3: Food-based diet

All of the above diets are designed to provide:

• Around 800–1,000 kcal
• Less than 100 g of carbohydrate
• Low fat
• High protein

You must choose one of the options and follow the instructions for that option. Please do not mix different diet options, as this may reduce the effectiveness of the diet.

Option 1: SlimFast® meal replacement diet

SlimFast® is a nutritionally complete, low-calorie diet (LCD) meal replacement product. With this diet, you are required to have:

• 4 x 325 ml ready-made SlimFast® bottles per day
• 2 cereal bowls of salad or vegetables from the list below. These can be blended into soup, boiled, steamed, roasted or eaten raw.

Salad and vegetable choices

• Artichoke
• Asparagus
• Aubergine
• Broccoli
• Brussels sprouts
• Butternut squash
• Cabbage
• Carrot
• Cauliflower
• Celery
• Courgette
• Cucumber
• Edamame beans
• Green beans
• Runner beans
• Leek
• Lettuce and other leafy greens
• Mangetout
• Marrow
• Mushroom
• Onion
• Peppers
• Pumpkin
• Shallots
• Spinach
• Spring onion
• Sugar snap peas
• Swede
• Tomato
• Turnip

How can you make your meals more interesting?

• Season your food: add herbs, chilli, spices, garlic, salt and pepper freely.
• Skip ready-made dressings: avoid adding oil or salad dressings.

Lemon juice and vinegar, including balsamic vinegar, are allowed.

• Keep hydrated: aim to have at least 2 litres of fluids per day, including water, sugar-free squash, herbal tea, black tea and black coffee without sugar.
• You can have 1 salty drink a day to help maintain electrolyte levels. For example, dissolve 2 teaspoons of stock, Marmite®, Bovril® or consommé in a large glass of warm water.

Please note: You must not have the powdered version of SlimFast®, as it is high in calories and carbohydrate.

4 SlimFast® shakes per day provide:

• 816 kcal
• 60 g protein
• 86 g carbohydrate
• 20 g fibre
• 21 g fat

Option 2: Milk and yoghurt diet

This diet is based on milk, yoghurt and additional fluids only.

Alcohol and all other food sources should be avoided for the duration of this diet.

Daily intake

• 3 pints of skimmed, semi-skimmed, lactose-free or soya milk per day. The milk can be hot or cold and flavoured with vanilla essence or sugar-free syrups, e.g. Crusha or Monin.
• 2 x 125 g low-fat plain or natural yoghurt, or 0% fat yoghurt, per day. Aim to avoid fruit yoghurts as they can be high in sugar and fat. You can add sugar-free syrups or flavourings to plain or natural yoghurt to adjust the taste if needed.
• An additional minimum of 2 litres of fluid per day, e.g. water, calorie-free or low-calorie squash or flavoured water, tea, coffee and fruit or herbal teas.
• Avoid adding sugar to your tea or coffee. Sweeteners can be used as an alternative. You can use milk from your daily allowance in tea or coffee.
• You will need to take supplements daily as this diet is not nutritionally complete. Examples include Sanatogen A–Z, Tesco’s A–Z and Centrum Advance/Performance.
• You can have 1 or 2 salty drinks a day to help maintain electrolyte levels. For example, dissolve 2 teaspoons of stock, Marmite®, Bovril® or consommé in a large glass of warm water.

Example meal plan

Meal	Suggestions
Breakfast	400 ml milky coffee 125 g yoghurt (low-fat plain or 0% fat)
Snack 1	300 ml glass of milk
Lunch	Oxo or Bovril® drink 300 ml glass of milk
Snack 2	Cup of tea with 100 ml of milk 300 ml glass of milk
Dinner	Oxo or Bovril® drink 125 g yoghurt (low-fat plain or 0% fat)
Snack 3	300 ml glass of milk

Option 3: Food-based diet

This diet is based on low-carbohydrate, low-energy, low-fat and moderate-protein meals, with additional fluids throughout the day.

Your meals should follow this format:

Breakfast:

• 1 carbohydrate portion
• 1 dairy portion

Lunch:

• No carbohydrate
• 2 protein portions
• 2 vegetable portions

Evening meal:

• 2 carbohydrate portions
• 1 protein portion
• 1 vegetable portion
• 1 dairy portion

Snacks:

• 2 pieces of fruit per day – these can be eaten at any time

What is a portion?

Protein	One portion
Raw lean meat (beef, pork, lamb, chicken)	Size of a pack of playing cards (100 g)
Ham, turkey	4 thick or 8 thin packet slices of ham, chicken or turkey (100 g)
Fish (salmon, trout, cod, haddock, mackerel)	1 fillet (125–150 g)
Canned fish in brine or spring water (tuna)	1 can (160 g)
Eggs (not fried)	2
Baked beans	4 tablespoons
Lentils, kidney beans, chickpeas, butter beans, tofu, Quorn	4 tablespoons
Nuts	2 tablespoons

Vegetables	One portion
Cooked vegetables (e.g. carrot, broccoli)	3 tablespoons
Side salad	Size of a cereal bowl
Tomatoes	1 medium tomato or 6–8 cherry tomatoes

Fruit	One portion
Apple, pear, banana, orange, peach	1 piece
Melon	1 slice
Grapes	12
Strawberries	7
Plums, apricots, satsumas, kiwi	2
Tinned fruit (peaches, pear)	3 tablespoons
Stewed fruit (apples, rhubarb)	4 tablespoons
Raisins, sultanas	1 tablespoon
Goji berries	1 tablespoon
Dried apricots	3

Dairy	One portion
Skimmed or semi-skimmed milk Soya or lactose-free milk	1 medium glass (200 ml) or ⅓ pint
Low-fat or diet yoghurt, including soya yoghurt	1 small pot (150 g)
Light fromage frais	1 small pot (150 g)
Low-fat cheese, e.g. Brie, Camembert, Edam or reduced-fat Cheddar	1 matchbox-sized piece (30 g)
Light cream cheese	30 g
Cottage cheese	1 large pot (200 g)

Carbohydrates	One portion
Breakfast cereals, e.g. Bran Flakes, crispies or Special K	3 tablespoons
Muesli or porridge	2 tablespoons
Shredded Wheat or Weetabix	1
Bread or toast	1 medium slice
Pitta bread	½ pitta or 1 mini pitta
Wholemeal bread roll	½ bread roll
Crackers	3
Crispbreads	4
Chapatti	1 small
Rice, cooked	2 tablespoons
Couscous, cooked	2 tablespoons
Pearl barley, cooked	2 tablespoons
Quinoa, cooked	4 tablespoons
Pasta, cooked	3 tablespoons
Noodles, cooked	100 g
Potatoes	2 egg-sized potatoes
Sweet potato	1
Plantain	½ (100 g)
Yam	70 g
Cassava, cooked	50 g
Muesli bar	1

Fats	One portion
Butter or margarine	1 teaspoon
Reduced-fat or low-fat spread	2 teaspoons
Low-fat or light salad dressing	2 teaspoons
Oil, any type	1 teaspoon

Example meal plan

Meal	Portion	Suggestion
Breakfast	1 carbohydrate portion 1 dairy portion	3 tablespoons of cereal OR 1 Weetabix OR 2 tablespoons of porridge made with ⅓ pint (200 ml) of semi-skimmed milk OR 1 slice of toast or bread with 30 g low-fat cheese (a small matchbox-sized piece)
Snack	1 fruit portion	1 banana
Lunch	No carbohydrate 2 protein portions 2 vegetable portions	Grilled chicken breast (200 g) OR 1 can of tuna in spring water OR 60 g low-fat cheese OR 8 tablespoons of Quorn or tofu with 6 tablespoons of cooked mixed vegetables (boiled, steamed or roasted)
Snack	1 fruit portion	12 grapes
Dinner	2 carbohydrate portions 1 protein portion 1 vegetable portion 1 dairy portion	6 tablespoons of pasta shapes with minced beef in 4 tablespoons of homemade bolognese sauce and 1 matchbox-sized portion of grated low-fat cheese, with a side salad (small cereal bowl) OR 4 tablespoons of bean or chickpea stew with 4 tablespoons of cooked rice, 3 tablespoons of low-fat yoghurt and a mixed leaf, tomato and cucumber salad (small cereal bowl)

Foods to avoid

It is important to avoid foods that are high in sugar and fat. These include:

• Sweets
• Chocolate and cakes
• Jelly
• Ice cream
• Sugary drinks, including fruit juice and fizzy drinks
• Alcohol
• Sugar added to hot drinks or food (sweeteners can be used as an alternative)
• Crisps
• Fried foods and takeaways
• Creamy or ready-made pasta or meal sauces. Choose tinned tomatoes for cooking, e.g. in bolognese sauces, stews and casseroles
• Meat or fish products coated in breadcrumbs. Choose fresh, lean options instead

Fluids

Aim to have a minimum of 2 litres of fluid each day, including:

• Water
• Tea or coffee (you can use milk from your daily dairy allowance – see above)
• Sugar-free squash or sugar-free flavoured water

You will need to start taking a multivitamin and mineral supplement once daily, as this diet is not nutritionally complete. Examples include Sanatogen A–Z, Tesco’s A–Z and Centrum Advance/Performance.

Additional information

• You may experience headaches or feel light-headed after starting the liver shrinkage diet. This is quite usual and should pass within the first few days.
• Constipation can become a problem when following this diet because it contains very little fibre. You may need to take 1–2 sachets of Fybogel each day or another laxative in tablet or powder form to help prevent this. We do not recommend taking lactulose during the pre-operative liver shrinkage diet.
• Patients taking insulin or gliclazide: if you have diabetes and take insulin injections or gliclazide tablets, please contact the healthcare professional who normally helps you manage your diabetes. It is likely that your insulin or gliclazide will need to be reduced because these diets are low in carbohydrate (less than 100 g) and may cause your blood glucose levels to fall lower than usual. Check your blood glucose levels 4 times a day. If you do not have a blood glucose meter, you can ask to have your blood glucose checked at your local pharmacy. Please contact your dietitian if you experience regular hypos (low blood glucose levels).
• Some weight loss is expected while following the liver shrinkage diet. You may experience changes to your menstrual cycle during this period. Women with PCOS (polycystic ovary syndrome) may also ovulate and become fertile while following the liver shrinkage diet, so it is important to use contraception.
• Please stop eating 6 hours before your surgery. You may drink water up to 2 hours before your surgery.