Gastric bypass post-op eating plan

Immediately after your surgery you need to allow time for your internal stitches to heal properly, swelling to settle and also allow your digestive system to adjust to the new way you will be eating.

It can take 3-6 months for the operation for everything to settle down totally – some days you will be able to eat foods without any problem and then, seemingly for no reason, the next day the same food will make your nauseated. Long term food intolerances are very uncommon.

The size of your stomach pouch and the swelling will initially limit the amount of food you can eat, but as time goes on you will be able to eat slightly larger quantities and you need to get to grips with a healthy eating plan if you are going to get the best results from your surgery and avoid nutritional side effects.

Whilst individual surgery centres do vary in their specific eating plan advice, here is general information and guidance for bypass patients.

The first week

You will start taking sips of water the day of your operation and the following day will probably be able to take free fluids. Once you are taking fluids easily, we recommend you stay on free fluids for one week. These include water, tea, coffee (use sweetners rather than sugar), herb/fruit teas, skimmed milk, low calorie fruit squashes, fruit juice, consommé, boullion, thin soup, sugar–free jelly.

Weeks 2–4

You can progress to pureed foods in small quantities (4–5 small meals per day). To start with, make your pureed food very runny (that will pour off a spoon) such as low fat yogurt (e.g. Muller Light), custard, soup, mashed potato with gravy, cheese (grated so that it melts into the potato without lumping), parsley or other sauce for flavour, stewed apple, tinned fruit (e.g. peaches, pears, apricots – in juice, not in syrup), Weetabix or ReadyBrek with lots of milk. After you are tolerating the very sloppy puree for a few days, think about adding more protein foods such as meat, fish, chicken, beans, lentils and eggs. All food should be pureed and low in fats and sugars.

  • The texture should be like smooth baby food (a good test is that it should pour off a spoon) and this is most easily achieved by using a food processor or hand–held blender. You can also use a potato masher for soft vegetables and potatoes and a sieve and spoon is also useful to remove lumps and pips. When you puree food, extra fluid may need to be added to get the smooth consistency. For savoury foods you might like to use packet or cook–in sauce mixes, gravy or the cooking water from your vegetables. For fruit and desserts, fruit juice will loosen the consistency.
  • The size of your meals – about 100g, or 5–6 tablespoons is the correct amount. Ensure you eat this slowly and take small mouthfuls. For the main meal of the day, you might find it easier to purchase and puree a ready meal such as a Shepherds Pie or Fish Pie (potato top) and a one–person serving will usually be sufficient for two meals for you at this stage.
  • Stop eating as soon as you start to feel full. Because your pouch is at the top of your stomach, the feeling of fullness you will get is different to what you are used to – it is felt more in your chest than in your stomach. Some people describe it as a tightness, some as a heaviness.
  • Drink 1.5 litres of water (2 1/2 pints) every day. Take it in 100–200ml glassfuls between meals, not with your meals.

Example meals during this stage:

Breakfast One Weetabix with milk or
A tub of yoghurt or fromage frais or
Three tablespoons of porridge or Ready Brek made up
Lunch Smooth soup (about a cupful)or
Scrambled egg
Dinner Shepherd's pie or
Fish pie or
Chicken in white sauce or
Mashed potato and cheese or
Pureed vegetables and mashed potato
Between meal snacks (once per day) Custard with stewed apple or mashed banana or
Milk pudding (e.g. rice or sago) or
Yoghurt or fromage frais
Fluids Water (not fizzy) or
Tea, coffee or skimmed milk or
Fruit juice or
Diet squash

Weeks four to six

Continue eating the same sort of food you were for the first four weeks, but it does not need to be pureed – mashing will make it the consistency of “toddler food”. It should be still fairly soft though and keep to the same small quantities and eating 4–5 times per day. Make sure you chew each small mouthful well.

After the first six weeks

You are now ready to continue on your long term eating plan. Remember, you are not just eating small amounts to reduce your calorie intake and lose weight, but you are aiming for a healthy nutritious eating plan as well. Each individual differs in the foods they can eat, but there are some golden eating plan rules to follow after a gastric bypass:

  • Avoid high sugar foods – a high sugar intake will cause dumping, an extremely unpleasant feeling of nausea, sometimes accompanied by abdominal pain, diarrhoea and faintness. Because your bypass alters the normal insulin response mechanism, when you eat sugar your body will produce an excessive amount of insulin. This can be considered an advantage of a gastric bypass, creating an in–built aversion to sugar! If this happens, lie down and stick to fluids until the feeling has passed and then review your eating patterns and reduce sugar intake. If you are prescribed liquid formulas of any medicines, especially antibiotics, please ask you pharmacist to dispense you a sugar-free brand.
  • Eat three meals per day – you should be satisfied eating three meals a day without getting hungry in between meals. Beware of developing 'grazing' eating patterns of small snacks throughout the day.
  • Eat healthy, solid food – soft food slips down easily but you can end up eating more over the course of the day. Many soft foods are also higher in fat or carbohydrates and as a consequence you may be taking more calories than you should and your weight loss will slow down or stop. Choose solid foods without too much sauce (e.g. small meal of chicken and vegetables with a spoonful of gravy or sauce) and you will eat less overall and stay full for longer.
  • Eat slowly and stop as soon as you feel full – Most obese people are used to rushing their meals and as there is a time lag from stretching the wall of your stomach and telling your brain you are full, you need to be careful with this one or risk pain or vomiting. Take tiny bites (cut meat up to the size of a pencil–top rubber) and chew each piece 10–25 times. Once you start to feel full, stop eating.
  • Keep your fluid intake up – Prior to your surgery you would have obtained a lot of your fluids from your meals, but with eating smaller quantities you need to increase your liquid intake. If you have a drink immediately before your meal you may also find that your stomach is still full and you can't eat your meal. So initially, avoid fluids half an hour before your meals, and for one hour afterwards. Calorie laden drinks, including alcohol, will simply add calories to your daily intake. Women need calcium, and this can be obtained from skimmed milk and other dairy products, but avoid juice, squashes and milkshakes. In the first few weeks you may find that fizzy drinks cause bloating and discomfort too, so these are best avoided.

A healthy diet

There are five main food groups and a healthy diet comprises a mix of them:

  • Protein foods – such as meat, fish, eggs, beans – include 2 to 3 60–90g (2–3oz) portions per day. You will have to particularly careful to chew meat, chicken and fish up thoroughly before you swallow – the recommended bite size is the size of a pencil–tip eraser.
  • Milk and dairy – choose low–fat cheese and limit amount to 30–60g (1–2 oz). Choose skimmed milk and low fat yogurt varieties. Three portions of dairy food aday will ensure that you are obtaining sufficient calcium from your diet.
  • Fruit and vegetables – try to have 4–5 portions per day. A small glassful of unsweetened tomato juice counts as one portion. Salads tend to be easily digested, and green vegetables are also generally easy to digest.
  • Carbohydrates – bread, potatoes and cereals – 2 portions per day. For many bypass persons, this group is somewhat harder to digest so you develop an in–built mechanism to reducing your carbohydrate intake! Replace soft bread in your diet with granary or wholemeal, or crisp breads which are more easily digestible. One small portion of 60–90g (2–3oz) at each meal will be fine.
  • Fats and sugary foods – use a small amount of olive oil for cooking and replace puddings with a low fat yogurt. As mentioned above, avoid the calorie–laden foods such as chocolate, sweets or ice cream which will cause dumping.

Multivitamins after a gastric bypass

It is very important that you take additional vitamins as you are no longer able to absorb sufficient amounts of them from your food. Vitamin and mineral deficiency is an avoidable complication after gastric bypass surgery. Unfortunately, vitamin levels are hard to detect accurately in the body and you could possibly become deficient before you start to show signs or symptoms of being so. If you are unable to afford to buy vitamin tablets, unable to swallow them, or are vomiting, it is important you speak to your GP or to the bariatric surgery team to ensure that you receive them in another format so that you do not become deficient. As always, prevention is much better than cure. The best source of vitamins and minerals is a healthy diet – for example, you will get your calcium if you are having three portions of dairy food in your diet each day (one portion = 1/3 pt milk, a matchbox-size piece of cheese or 1 pot yogurt).

We recommend:

  • One multivitamin tablet every day – choose one that contains
    • Vitamins B1 (thiamine) –over 1.4mg
    • Vitamin B12 –over 1 μg
    • Folacin (folic acid) – over 200 μg
    Examples of branded products that are suitable are Centrum Complete A-Z (still available in the non-chewable tablet format), Sanatogen Gold A to Z, Seven Seas Multibionta and Boots Adult Multi-vitamins.
  • Additional iron in the form of ferrous sulphate 200mg tablets twice a day if you are prone to anaemia or if your routine blood tests show you are becoming anaemic (your GP will tell you).
  • Calcium – 800–1,000mg per day if you are not having your dairy foods as mentioned above – usually taken in the form of a chewable tablet such as Nature’s Aid.