Weight to Go Blog

Weight to Go Blog

The complete bariatric surgery diet guide

Entered by: Weight to Go Team @ 10:25:47 on 11/07/17

Bariatric surgery is a lifesaving procedure and it will help you lose weight, improve your mobility and even increase your life expectancy (1). However, preparing for weight loss surgery can be very overwhelming and exciting at the same time which can sometimes lead to overlooking important success factors such as the necessary pre-and post-op diet.

This guide will help you understand which foods are safe to eat during the critical period around your surgery (5 days pre-op and 4 weeks’ post-op). You will also learn why following the specific nutritional guidelines is essential to your weight loss surgery success.

Before surgery, you need to follow an 800-1200 calorie diet to reduce the glycogen (storage form of carbohydrate), water and fatty deposits in the liver and thus reduce the liver’s overall size. This allows the surgeon to safely move the liver aside, reducing the risk of surgical complications. It also helps with the transition from normal diet to the post-op liquid diet.

The pre-op diet is not optional. How long you will need to follow the diet depends on your BMI: The pre-op diet must be nutritionally balanced - low-fat, low-carb with moderate protein. We highly recommend the Weight to Go Surgery Box which provides everything you need for your pre-operative diet and 4-week post-operative diet (in bold on Table 5. overleaf) but if you prefer to make your own food you can combine some Weight to Go products, eg shakes with alternative meals below. Don’t be tempted to eat a large meal the day before surgery as you will compromise the liver reducing effects of the diet.





You must follow a liquid diet for the first two weeks after your band operation. Liquids should be smooth and not contain any ‘bits’ as they may cause discomfort or pain or get stuck. Use a sieve if you are unsure. If a drink will go through a straw, then it is the correct consistency for this stage. However, do not drink through a straw as you may take in a lot of air and this could cause discomfort. Sip slowly but frequently throughout the day at the start of the liquid stage, allowing a few minutes between sips. As the days go by, you can progress to cupful of drinks taken slowly over a 15 - 20-minute period.


In the first two weeks after surgery, you can build up to taking around 200mls at any one time. If you experience pain, discomfort or regurgitate your drinks, take smaller sips and allow more time between sips. Some people find warm drinks go down more easily to start with; others find that sucking ice cubes can help if you are struggling to get fluids down.


Some people get a ‘furry mouth’ in the first month as when you have nothing to chew on, your mouth produces less saliva to protect your teeth. Using a mouthwash and brushing your teeth well will help. You could also try drinking pineapple juice which is good for removing the ‘furry mouth’ sensation.




Each day you may choose;


-4 items from Protein list

-And 1 or 2 items from Limited list

-And as much as you like from Free list

PROTEIN list (choose 4 items per day)


  • Weight to Go® shake (hot or cold)
  • Weight to Go® soup
  • 400ml (2/3pt) semi-skimmed or skimmed milk
  • 400ml (2/3pt) soya milk with added calcium
  • 2 smooth diet yoghurts (125g each) to blend with milk or water to a ‘drinkable’ consistency
  • 3 heaped tablespoons skimmed milk powder
  • 15g protein powder e.g. soya or egg (obtainable from health food shops or a pharmacy); you may need to use these to obtain your protein if you do not like dairy products. They can be mixed into soups or fruit or vegetable juices

LIMITED list (optional 1 - 2 items per day)


  • Oxo, Bovril, Marmite or stock cubes dissolved in hot water
  • Soups - tinned, dried, cuppa, homemade. You may need to dilute them with extra water or add an Oxo cube, Bovril or Marmite and sieve to remove all bits and lumps
  • 1 small glass (150ml) unsweetened fruit juice. If you have a juicing machine you can make your own tasty combinations e.g. beetroot and orange, carrot, celery and apple. Dilute with approximately 150ml water and sieve to remove all bits and lumps
  • 1 glass (200ml) vegetable juice e.g. carrot, tomato, mixed vegetable, V8
  • 1 x 100ml low-fat, low sugar Actimel or similar
  • 1 x 100 - 150ml Vie or other smoothie drinks
  • Low-calorie hot chocolate, Ovaltine or Horlicks
  • ½ banana or small portion of soft fruit to make into a ‘smoothie’ with milk; make sure this is a thin consistency and sieve to remove all bits and lumps

FREE list (unlimited)


  • Water; plain or flavoured low-calorie variety (not carbonated)
  • Low-calorie, no added sugar or sugar-free squash
  • Tea, including herbal teas
  • Coffee, preferably decaffeinated


Weight loss surgery is an exceptional tool that can change your life, but you need to work with and if you follow your surgeon's guidelines you will go a long way! 







View Surgery Box