Thinking about getting obesity surgery?

Download our free PDF guide

Weight loss surgery has been shown to have a profound impact on obesity-associated health risks.  As indicated in Table 1 (Section 1), those undergoing gastric banding can expect to lose around 50-6% of their excess weight, whilst for those opting for gastric bypass this will be somewhat higher – around 60-70%.  Other procedures such as biliopancreatic diversion (BPD) and duodenal switch may result in 70-80% excess weight loss, though these are much more complicated and risky procedures. 

All surgical procedures for weight loss have a dramatic impact on obesity-associated health problems.  There is, quite simply, no other therapy which improves quality of life so much. And, in particular, no other therapy that so clearly protects people from premature death and disability.

The following is a brief overview of some of the more important conditions which are improved or corrected by obesity surgery. They are summarized in Table 2.

[NB. Please note that the percentage estimates for benefit are dependent on the specific surgical procedure undertaken]

Type II diabetes

Most people with type II diabetes are overweight and about half are obese. Diabetes damages most of the systems of the body and shortens life expectancy. If you are obese and have type II diabetes it is imperative that you lose weight.  Studies show that following weight-loss surgery, 80-90% of patients with type II diabetes will have either complete resolution of their diabetes or marked improvement in their diabetic control.


Raised blood pressure is very common among obese patients – up to 40-50% of obese subjects in some studies. But following obesity surgery, up to 75% of hypertensive individuals will be able to either reduce or stop their anti-hypertensive medication.


Dyslipidaemia is the medical term for abnormal blood fats. Individuals with weight problems often have abnormally high levels of cholesterol and triglycerides (both forms of blood fats) which are known to increase the risk of heart disease. Following weight loss surgery and depending on the procedure undertaken, around 75-95% of patients will show either complete resolution or, at the very least, major improvements in their dyslipidaemia.

Sleep Apnoea

Obstructive sleep apnoea is a condition in which you literally stop breathing during your sleep (the word apnoea means to stop breathing). Your partner may tell you that you are snoring loudly, but then you seem to stop breathing completely – sometimes for up to a minute. This is obviously distressing for your partner until finally – sometimes accompanied by grunts and snorts - the normal breathing pattern starts all over again. This can happen many times (50 or even more) during the night, leading to daytime sleepiness and fatigue.  Sometimes snoring and poor sleep patterns can occur in the absence of true apnoea. 

Sleep apnoea is due to pressure from excess fatty tissue in the neck, leading to narrowing of the airways and breathing difficulties. For some patients this is severe enough to require the use of a continuous positive airways pressure (CPAP) machine at night. Some element of apnoea is common in obese individuals and may be found in up to one-third of patients undergoing weight-loss surgery. 

Studies have demonstrated that surgery has a dramatic impact on sleep apnoea.  Around 75-90% of patients on CPAP will be able to discontinue this and almost all will experience marked improvements in sleeping patterns, with reduced snoring and daytime fatigue.  Partners are usually delighted!


This problem is sometimes referred to as gastroesophageal reflux disease or GERD, but more commonly just as heartburn or reflux.  More than half of all obese individuals complain of heartburn which is the pain or discomfort you get behind the breastbone when acid from the stomach travels back up the gullet causing irritation and inflammation. About 20% of patients take regular medication to control their reflux symptoms.

The good news is that although reflux is very common before weight loss surgery, afterwards almost all patients are completely cured by the procedure. More than 90% of patients undergoing surgery will experience rapid improvement in symptoms of reflux oesophagitis.   

Stress incontinence

Among women, obesity is a major risk factor for urinary stress incontinence, or uncontrollable urine loss. A large, heavy abdomen and relaxation of the pelvic muscles due to morbid obesity may cause the valve on the urinary bladder to weaken, leading to leakage of urine with coughing, sneezing, or laughing. While urinary stress incontinence may occur regardless of someone’s age, gender, or body mass, the condition tends to be more frequent and more severe in those with weight problems. Weight loss surgery has been found to improve stress incontinence. Less weight (and therefore pressure) is placed on the bladder and other beneficial physical changes occur to improve or eliminate the problem.

Infertility and Polycystic Ovarian Syndrome (PCOS)

Menstrual irregularities (including abnormal flow and cycle interruption) and infertility are very often associated with chronic weight problems. In overweight women, weight loss as little as 5% of baseline weight may be enough to restore ovulation and fertility.

Polycystic ovarian syndrome (PCOS) is a common hormonal disorder occurring in women of childbearing age that can cause infertility and other reproductive health conditions. Classic symptoms of PCOS include obesity, an increase of facial and body hair (hirsutism), acne, irregular menstrual cycles, and infertility.

Obesity surgery has been shown to correct the underlying hormonal problems in PCOS, to reduce insulin resistance and to restore fertility in most (80-90%) of cases.   


Almost all patients who have asthma will show marked improvements as a result of weight loss following weight loss surgery. In many cases there will be no further attacks and no need for continuing therapy.

Liver disease

Non-alcoholic steatohepatitis (NASH) is the term used for a condition where there is inflammation of the liver associated with excessive fatty deposits. The pattern of abnormalities is similar to those observed in relation to heavy alcohol consumption, but in the case of NASH is not attributable to alcohol.  NASH is strongly associated with obesity, especially in those whose fat is deposited around the middle (central fat). The inflammation caused by the fatty deposits can lead to scarring of the liver and – in some cases – liver failure. NASH is becoming increasingly recognized as yet another serious consequence of chronic obesity.

The good news is that surgery has a remarkable and rapid impact on NASH, with complete resolution of the disease in more than 80% of cases. 

Back pain and arthritis

Osteoarthritis is one of the commonest forms of arthritis. Known as the “wear-and-tear” kind of arthritis, it is a chronic condition in which there is a breakdown of a joint’s cartilage. For anyone who is obese, excess body weight placed on joints, particularly knees and hips, results in rapid wear and tear and pain caused by inflammation. Similarly, bones and muscles of the back constantly are strained, causing disk problems, pain and decreased movement ability. While osteoarthritis may occur regardless of someone’s age, gender, or body mass, the disease tends to be more severe in the obese.  Following surgery, patients experience major improvements in arthritis, joint and back pain and mobility.  As less weight is placed on joints, the strain is reduced and overall quality of life is significantly improved.  

Psychological well being

There are many reasons people with obesity experience depression. Many of the everyday activities people with healthy body weight take for granted are big challenges for a seriously overweight person. These activities may include walking, social interaction, finding clothes that fit and fitting in public seats. While depression may occur regardless of someone’s age, gender, or body mass, it tends to be more severe in the obese.

A number of studies have demonstrated sustained improvements in psychosocial factors following obesity surgery. Depressive symptoms and anxiety are less, social interaction is improved, self-esteem and perceived attractiveness improved and overall quality of life and vitality are enhanced.


Summary of the health benefits of obesity surgery

Type II diabetes – Around80-90% of patients will have either complete resolution of their diabetes or marked improvement in diabetic control

Hypertension – 75% of patients will be able to reduce or stop their ant-hypertensive medication

Dyslipidaemia – 75-95% show major improvement or complete resolution of abnormal blood fats

Sleep apnoea – around 75-90% of those on CPAP† will be able to discontinue this and almost all will experience major improvements in sleeping patterns and reductions in snoring and daytime fatigue.

Reflux – more than 90% of patients will experience major and rapid resolution of symptoms

Stress incontinence – the majority of people experience marked improvement or complete resolution of symptoms.

Infertility and PCOS*  – obesity surgeryhas been shown to correct the underlying hormonal problems and to restore fertility in 90% of cases

Asthma – almost all patients with asthma experience marked improvement in symptoms and a reduction in medication

Liver disease (NASH)¶  – following surgery there is complete resolution of the disease in 80% of cases

Back pain and arthritis – patients experience marked reduction in joint and back pain and increased mobility

Psychological wellbeing – depressive symptoms and anxiety are less, social interaction is improved and overall quality of life and vitality are enhanced

† Continuous Positive Airways Pressure

*  Polycystic ovarian syndrome

¶   Non-Alcoholic Steatohepatitis

Thinking about getting obesity surgery?

Download our free PDF guide


Latest news

Football legend opens Spire Thames Valley's new MRI and imaging department

London Imaging Centre have introduced a new fast response phone consultation service

Fisrt iDuo ConforMIS bicompartmental patient specific knee replacement

What are the benefits?
FREE Guide
FREE Guide

Obesity surgery and weight loss surgery guide

  • Types of obesity surgery
  • Risks of surgery
  • Benefits of surgery


Find a ...

Connect with us on: