After gastric bypass surgery you will need to make changes to your eating patterns. The diet after surgery progresses from a liquid diet to a pureed diet to a soft diet and then a modified diet. This progression is designed to allow your body to heal. It is very important that you follow the diet’s progression to maximise healing and minimise risk of complications.

 Before Gastric Bypass Surgery

For two to six weeks before your surgery you are required to follow a low calorie diet. The programme followed is Optifast. Your dietitian and surgeon will advise on the amount of time you will need to follow this diet.

Why is it necessary to lose weight pre-surgery?

• To lower body fat levels for better access for the surgeon i.e. safer surgery
• To reduce the size of your liver which would otherwise be in the way
• Greater ability to adapt to post-operative dietary requirements
• Improved surgery outcomes
• Reduced operating time and post operative risks
• Improved physical function and mobility post-surgery

What is Optifast?

• Very low calorie diet (VLCD) that is < 800kcal per day
• Nutritionally complete. (All the protein, vitamins and minerals that you need)
• Involves three ‘meals’ per day, which can be milkshakes soups or bars

How does it work?

• Each VLCD meal is taken at usual meal times and provides all essential nutrients
• You need to drink at least 2 litres of the following fluids per day:
  – Water
  – Diet soft drink
  – Black tea or herbal tea without milk or sugar
• A maximum of 2 cups of low starch vegetables are allowed per day
• Replacement fibre – 1 tsp of psyllium or equivalent per sachet of Optifast eg Metamucil or Benefibre
• Please see attached “foods allowed” lists below for more information
• If you are having trouble with this diet or having symptoms such as nausea, please call your dietitian, surgeon or your GP.

Additional Allowances

Allowed				Avoid
Fruit	one of – 200g strawberries, 1 lychee, 1 apricot, 100g cooked rhubarb, 1 slice of pineapple, 2 passion fruit, 100g grapes, 1 lime, 1 apple, 50g cherries, 1 mango, 1 medium orange, 1 peach, 1 small pear, 120g pear in natural juice, 120g plums, 5 prunes			all other fruit, including banana
Low starch and green vegetables (2 cups per day)	alfalfa sprouts asparagus beans bok choy broccoli brussel sprouts celery cabbage capsicum carrots	cauliflower cucumber eggplant garlic lettuce leeks mung beans mushrooms onions	radish shallots silver beet snow peas spinach squash tomato watercress zucchini	corn green peas legumes lentils potato pumpkin kumara taro green banana
soups	stock cubes	vegetable soups (using allowed vegetables)	miso soup	all others
sauces and condiments	lemon juice vinegar worcestershire sauce	soy sauce (in moderation) chilli	mustard tomato paste
herbs and spices	all herbs and spices
miscellaneous	artificial sweeteners	unsweetened lollies/gum	diet jelly essence –e.g  banana, mint, strawberry
calorie free fluids (at least 2 litres extra per day)	water tea diet soft drink	diet cordial mineral water		fruit juice alcohol

 

After Gastric Bypass Surgery

Day Zero (evening of surgery)

• Ice to suck, sips of water

Day One

• 1 litre of water (slowly, as tolerated)

Day Two

• Bariatric free fluid diet, progress to bariatric pureed diet as tolerated (very small amounts of puree/mashed food only, half a teacup at a time at most)

Day Three to Week Three

• Progress to bariatric pureed diet as you are able

Week Four onwards

• Small meals of soft food that is high in protein and low in fat and sugar

General Information

During all of the above stages and when you have recovered fully from surgery it is crucial that you:

• AVOID liquids with meals (do not drink 30 mins pre and post eating)
• Drink between meals and aim for six to eight glasses of fluid per day
• Follow a general healthy diet, low in fat and sugar

Constipation

Because you are eating less, constipation may be a problem. Keeping up with your fluid intake and occasionally using a gentle laxative will help with this. Most patients will not feel the urge to have bowel movement for several days after surgery. This is because you will be taking very little food and is entirely normal.

Dumping Syndrome

• This can make you feel awful, but is not dangerous
• It occurs due to the ‘dumping’ of highly concentrated carbohydrate (sugar) into your bowel
• Symptoms include; dizziness, abdominal pain, flushes, diarrhea
• It can occur straight after eating or one to three hours after eating
• AVOID all high sugar containing food and fluid e.g. lollies, ice cream, juice/cordial, soft drinks

Handy Hints

• If you try to eat too much too quickly vomiting or regurgitation may occur
• Do not consume liquid calories such as fruit juice, soft drinks, cordial, or milkshakes
• Eat slowly, chew all food well and take time with your meals
• Ensure you have an adequate protein intake. Protein should be eaten before carbohydrates (starchy) foods
• As soon as you are home after your surgery start taking a multivitamin daily such as Centrum

Puree Diet

• To be followed until three weeks after your surgery
• Eating too much can result in complications before healing has occurred

Important Points

• Eat slowly
• AVOID very hot or very cold foods
• DO NOT drink within 30 minutes of meal times
• It is normal to be managing only very small amounts during this phase. Eating with a teaspoon from a small plate is a good idea.

Foods allowed	Foods to avoid
high protein, low fat pureed foods: low fat yoghurt, milk, cottage cheese, porridge, mashed weetbix, softly scrambled or poached eggs, pureed meat/chicken/fish, pureed/mashed vegetables/potato, smooth soups, pureed fruit	raw fruit raw vegetables breads rice pasta nuts seeds skins solid food
low fat products	butter margarine oil avocado cheese (high fat varieties) ice cream cream
low sugar products low calorie drinks water herbal teas	cordial soft drinks jelly

 

Sample meal plan (initially only 1-2 tablespoons of food at a time):

Breakfast	Weetbix or Optifast low fat milk or 1 tablespoon low fat yoghurt 1 tablespoon pureed fruit
Lunch	smooth vegetable/pumpkin soup scrambled egg
Dinner	pureed chicken and low fat gravy or mashed fish pureed potato/pumpkin/vegetables
Snacks (x3/day)	puree fruit, mashed banana, low fat yoghurt and milk

 

Soft Diet

• After your puree diet move to a soft diet for two weeks. This is food you can mash with a fork. Then gradually move to more solid foods
• Aim to have only three meals per day
• You should be using a bread and butter size plate

Food group	Foods allowed	Foods to avoid
meat, chicken and fish	Foods allowed tender chicken, fish and meat in bite sized pieces or minced. shaved ham, turkey or chicken tinned salmon and tuna in spring water	hard or stringy meat fat, chicken skin or gristle. fried meats
milk and milk products	low fat milk, cottage/ricotta cheese, low fat yoghurt	ice cream, high fat cheeses, cream and full fat milk
Fruit	soft fruits: peeled pears, apples, stone fruit, melon	pips, skins, pith
Vegetables	cooked vegetables: mashed, stir fried, grilled or boiled introduce salads slowly	tough or raw vegetables: beans, corn, celery, broccoli stalks etc
breads and cereals	low fat crackers e.g. cruskits, rice, pasta, noodles, porridge, weetbix, bran flakes	doughy bread, muesli, high fat cereals.
Drinks	diluted juice, diet soft drinks and cordials, herbal teas, coffee or tea with low fat milk	soft drinks, energy drinks, milkshakes, full fat milk drinks, juice
Miscellaneous	artificial sweetener, herbs and spices, marmite, stock, low fat hummus, minimal oil when cooking	sugar, chocolate, sweets, syrups, jams, butter, cooking oils, potato chips, high fat crackers, creamy sauces.

 Handy Hints

• Introduce more solid foods after a few weeks e.g. salads, red meat
• AVOID bread and instead have low fat crackers e.g. rice crackers, cruskits
  – look for <5 g fat per 100g
• Small amounts of toasted vogels bread can be eaten. Avoid soft white breads
• Continue to chew food well and take your time eating
• AVOID fluids with meals
• Do not over eat as this will make you uncomfortable and may cause vomiting
• Continue to eat regular meals and select healthy food options to optimise your continued weight loss
• You will need to make sure that your meals are nutritious and include all the nutrients your body needs
• Choose foods that you enjoy and take time to savour their flavours

Food to include at each meal:

Protein
You need to include low fat protein at each meal to ensure you maintain your muscle stores and loose fat stores e.g:

• lean red meat two to three times per week e.g. lean mince, eye fillet
• fish and chicken (no skin)
• low fat dairy products e.g. trim milk, low fat yoghurt and cottage cheese
• tofu, beans and lentils e.g. baked beans, hummus, kidney beans

Hair loss, though  temporary, can be a problem if there is inadequate protein in your diet. Using protein powders (muscle building formulas) in fruit smoothies and purees can be a good way to increase your protein intake. Protein helps to keep you feeling satisfied for longer.

Fruit and vegetables

• fresh, frozen or canned vegetables. AVOID hard seeds and pips
• fruit that has been peeled and membranes removed

Carbohydrate/starchy food

• eat two to four serves per day
• 1 serve = ½ cup pasta/cereal, 1 slice of bread, 1 egg-sized potato
• potato, bread, rice, pasta and cereals should be eaten in very small amounts only
• if you are having bread use wholegrain varieties e.g. Vogels as this will fill you up more
• protein foods should take priority

Fluid

• 6 – 8 glasses of fluid per day (do not count coffee, alcohol or caffeine drinks)
• AVOID full strength juice, cordials, high calorie fizzy drinks, milkshakes etc

Fats

• Use very minimal margarine or preferably none
• Vegetables can be stir fried with a teaspoon of olive oil
• Generally avoid oil for cooking. Grill, bake, boil, stir fry or dry roast
• AVOID fatty meats e.g. sausages, luncheon sausage, salami

Handy Hints

• Order entree-size meals when dining out
• Aim to exercise 45 to 50mins five days per week. This should be continuous cardio type of exercise – rather than weights – of enough intensity to “raise a sweat”
  – Brisk walk, cycle, cross-trainer, aqua jogging or swimming. Weight-bearing exercise is best for weight loss maintenance

 

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