Points to Consider

The Pre-operative Diet (Liver Shrinkage or LSD diet)

  • You will be expected to follow a liver shrinkage diet for 2 – 4 weeks before any bariatric operation (except the gastric balloon) to prepare your body for surgery.
  • When you are overweight, your liver can become enlarged through excess fat and glycogen (sugar) deposits. This enlarged liver can make surgery difficult.
  • This diet encourages your liver to use up the excess glycogen and fat stores, thereby making surgery easier by shrinking the size and weight of your liver.
  • It is essential that you follow this diet to reduce the risk of damage to the liver. If you do not strictly adhere to it, the surgeon can tell and they may decide it is too risky for the operation to go ahead.
  • You will be expected to take a chewable Multivitamin supplements (A-Z complete) on this diet

The Post-operative Diet

  • You will follow a special diet for approximately 6 weeks after any bariatric surgery (except for the gastric balloon).
  • This allows your body to recover and heal after the operation, and for you to become used to the restrictions.
  • After 6 weeks you should be on normal food consistencies. This will be discussed at your initial surgery group session and a detailed booklet provided.

Please note, you may require some medication changes after surgery. For the first 6 weeks you can take medication if it is less than 1cm in diameter or a capsule smaller than a tictac. Anything larger will need to be broken in half or crushed. Advice about crushing medication can be sought via your pharmacist.

Time off Work

It is best to discuss this with the bariatric surgeon or the clinical nurse, but generally it is expected for patients to have 4-6 weeks off depending upon your occupation. Gastric balloon patients would be expected to go back to work within a few days, generally once nausea and vomiting has subsided.

Mental Health and Well-being

Bariatric surgery aims to reduce patients’ weight, therefore improving their general well-being and health, and extending their life expectancy. Many people notice a change in their mood after surgery, with some reporting improvements post operatively. However surgery does not necessarily improve any existing psychological, career or relationship difficulties or other mental health issues.

Often, food can provide a source of comfort and a means of self-soothing or regulating unpleasant or difficult emotions. If you notice that you eat in response to certain emotions, you will need to learn additional ways of managing this.

If you have a history of eating disorders such as bulimia, binge eating or overeat regularly in response to difficult situations or feelings, please speak to a health care professional about this prior to any bariatric operation. The Bariatric Psychology team can help you discuss these difficulties and explore alternative ways of responding to difficult situations and emotions.

If you are receiving care from a community mental health service, please inform them that you are to have surgery so they can provide you with any extra help you need after surgery. If you take any medication for your mood, please ensure you speak to your GP or pharmacist if they are too large to take post-surgery. For the first 6 weeks you can take medication if it is less than 1cm in diameter or a capsule smaller than a tictac.


We currently have a smoke free policy meaning all patients undergoing surgery need to have stopped smoking for 6 months before being placed on the waiting list. Smoking affects wound healing adversely and can increase the risk of stomach ulcers in the long term after bariatric surgery.


All patients are expected to comply with national alcohol consumption guidelines. These state that men and women should have a maximum alcohol intake of 14 units per week. Surgery will be delayed until patients are within these guidelines. After surgery, patients are recommended to avoid alcohol for 12 months.


Losing weight can increase fertility. However, we recommend that you do not become pregnant for 18 months after the gastric bypass or sleeve gastrectomy. The associated rapid weight loss with both, places the body under great stress, depletes its stores and restricts what you can eat. This can put the baby’s development at risk.

Excess Skin

Significant weight loss in people who have been overweight for many years, can result in skin becoming loose, as the skin and underlying tissues cannot return to their previous state. This is particularly true of skin on the stomach, arms and legs. Although there are several surgical procedures to remove excess skin, these are not routinely funded through the NHS.