Weight loss surgery 

Introduction 

Understanding BMI results in adults

Find out how to calculate your body mass index (BMI) and interpret the results correctly.

Body mass index and obesity

The most widely used way to measure your size is to calculate your body mass index (BMI). This is your weight in kilograms divided by your height in metres squared:

  • If your BMI is 25-29.9, you are over the ideal weight for your height (overweight).
  • If your BMI is 30-39.9, you are obese.
  • If your BMI is over 40, you are very obese (known as morbidly obese).

BMI does not provide an accurate assessment of weight in all circumstances, such as in people who are very muscular or children going through a sudden growth spurt.

Vicky Finch

'My gastric band surgery'

Vicky talks about the changes she had to make to her diet before and after weight loss surgery, and what it's like living with a gastric band

Weight loss surgery, also called bariatric surgery, is used as a last resort to treat people who are dangerously obese (carrying an abnormally excessive amount of body fat).

This type of surgery is only available on the NHS to treat people with potentially life-threatening obesity when other treatments, such as lifestyle changes, haven't worked.

Potentially life-threatening obesity is defined as:

  • having a body mass index (BMI) of 40 or above
  • having a BMI of 35 or above and having another serious health condition that could be improved if you lose weight, such as type 2 diabetes or high blood pressure

For people who meet the above criteria, weight loss surgery has proved to be effective in significantly and quickly reducing excess body fat. 

However, it is always recommended that you try to lose weight through a healthy, calorie-controlled diet and increased exercise before you consider weight loss surgery, as surgery carries a risk of complications and requires a significant change in lifestyle afterwards.

Because of these associated risks, most surgeons, whether they are working privately or for the NHS, would only consider a person for surgery if there was a clinical need, and not just for cosmetic reasons.

Read more about who can use weight loss surgery.

Availability of weight loss surgery

Even if you are eligible for weight loss surgery, the demand for this surgery on the NHS is currently higher than the supply in many areas of the country. Therefore, there may be a considerable waiting list.

Weight loss surgery is also available privately. Prices are around: 

  • £5,000-8,000 for gastric banding
  • £9,500-15,000 for gastric bypass surgery

An increasing number of people are seeking treatment abroad as costs for private treatment are often cheaper in other countries, but this option should be considered carefully. For more information, see planned treatment abroad.

Types of weight loss surgery

The two most widely used types of weight loss surgery are:

  • gastric band, where a band is used to reduce the size of the stomach so a smaller amount of food is required to make you feel full
  • gastric bypass, where your digestive system is re-routed past most of your stomach so you digest less food and it takes much less food to make you feel full

Several other surgical techniques may be recommended in certain circumstances.

Read more about how weight loss surgery is performed.

Life after weight loss surgery

Weight loss surgery can achieve often impressive results in the amount of weight lost, but it should not be seen as a magic cure for obesity.

People who have had weight loss surgery will need to stick to a rigorous and lifelong plan afterwards to avoid putting weight back on or long-term complications.

This plan will include:

  • a carefully controlled diet
  • regular exercise

The rapid weight loss may cause relationship problems, for example with a partner who is also obese, and it may lead to unwanted loose folds of skin, which may need further surgery to correct.

Also, many people with mental health problems, such as depression or anxiety, find that these problems do not automatically improve because they have lost weight.

It is important to have realistic expectations about what life after weight loss surgery will be like.

Read more about life after weight loss surgery.

Risks

As with all types of surgery, weight loss surgery carries the risk of complications, some of which are serious and potentially fatal, such as:

It is estimated that the risk of dying shortly after bariatric surgery is around 1 in 200.

However, this risk can be as high as 1 in 40 if you have other risk factors such as high blood pressure or a BMI of 50 or above.

Read more about risks of weight loss surgery.

Results

As long as a person is willing and able to stick to their agreed plan afterwards, surgery can effectively reduce their weight and treat conditions associated with obesity, such as diabetes.

Recent research carried out in America found that on average:

  • People with a gastric band will lose around half their excess body weight.
  • People with a gastric bypass will lose around two-thirds of their excess body weight.

Both techniques also lead to a considerable improvement (and sometimes a complete cure) of obesity-related conditions, such as diabetes or high blood pressure.

Read more about the results of weight loss surgery.

Last reviewed: 05/11/2012

Next review due: 05/11/2014

Ratings

How helpful is this page?

Average rating

Based on 54 ratings

All ratings

Add your rating

Comments are personal views. Any information they give has not been checked and may not be accurate.

PrincessTeacake said on 28 May 2013

I am writing this to ask for help. I'm a female, aged 24, and currently weigh in at 21.7stone with my height being 5.8. Well I have always had an issue with my weight being a size 12/14 at school then size 16-18 at college. And now rest at a size 22-24. I am very insecure and very depressed about my weight. I have been to the doctors many of times to be told I'm not big enough. Well I'm pretty sure 21stone is more then enough! I hate the way I look so much I don't even let my fiancé see me in the nude. I hate being like this, it's always been a big issue. I have depression and anxiety and I'm worried I'm going to get diabetes soon as my auntie and mum currently have it. I have tried many diets, slimming tablets and even going to the gym 3 days a week but my weight barely comes off. Most I've lost is 1stone and a half but had a bad day and my depression got the better of me and I put it back on In a matter of a few weeks. I'm In this viscous circle and I can't get out. What does it take for me to get a gastric bypass on the NHS??? I pay my taxes! I don't want to be thin to be a model or just like everyone else I want to be thin to be healthy to get my confidence back to wake up everyday and not cry!

Report this content as offensive or unsuitable

mysticalpickle said on 21 May 2013

Hi, im a 40 yr old mum, im 5ft 7, i now weigh 20stone. I suffer with Fibromyalgia, severe depression/ migraines, i have a wheat and glutten issue( some diet foods make me worse) Ive had an acl recon, ive damaged ligamemnts in one ankle, I suffer with Achillies tendonopothy on both feet/ankles, i suffer with plantar facilitus on both feet and ganglion syst on one foot which can not be removed, its hard to breath at times, I also have ligament damage on one of the shoulders and carple tunnel damage in one of my wrists after a car accident. my sciatica is in overdrive. I do not claim disability as i am not disabled enough lol I can not walk unaided, im sick of taking pills, i can not attend a gym due to the above conditions, i have tried 5 diets( cambridge, lighter life, slimming world, weightwatchers and diet chef) i am not working , not because I am not qualified or dont have the incentive, but medical conditions stop me and companies wont epmploy insurance risks or obese( fact). I have begged for help from my gp in the past, and they suggest the normal.(gym and healthy food) I dont smoke, dont do drugs nor do i drink. My mental and emotional state are so low, its hard to see myself live the rest of my life like this. I have 2 children and want to be around for them, grandkids etc to enjoy my life and etc. i dont have a personal life, everything is sooo painful, i desperatly need some help. Having read the types of op, bypass, band etc , i read about the balloon too. which is similar to the band but can be altered to fix the need of each person. im going up and up in weight, and its hard for us over weighties to keep weight off through daily routine. I have no friends for support and family is miles away. Can anyone suggest something, im not after sympathy or a magic wand, but i just cant get me wobbly bits off. Im quite scared to go back to my GP. Would i be a good candidate for these procedures? surely having a better lif, healthier life is better than struggles

Report this content as offensive or unsuitable

nata1ie said on 08 May 2013

Im 32 5' 3" and a bmi of 53 since i had my daughter when i was a size 10 ive suffered from extreme lower back pains which made me put the weight on as i can hardly walk with the amount of pain im in i dont leave the house as apart from the pain, ive gained a phobiia that everyones looking and laughing at me.
Ive tried excercise to get my weight down but because of the pain i cant do it so i asked my doctor for weight loss surgery and he refused im at a loss why did he refuse when im obviously needing the help !! I just dont know where to turn anymore, if this comment gets read then plz help me xx

Report this content as offensive or unsuitable

Marina3 said on 05 October 2012

I am 18 years old, 5"3 and 105kilos. My BMI is 41. I have always been big in my life due to many bad experiences during my early life. I have been to my doctor today to discuss my weight, they just told me what I have already been trying to do since I was 14. I have done every diet possibly, hypnosis (didn't work), calorie controlled diets, non carb diets, all have not worked. I have quite an active life style. Yet I also suffer with Asthma. My weight can extremly make me depressed and stop me from doing what I want to do. I really need medical help now, Please.

Report this content as offensive or unsuitable

gilboandco27 said on 07 August 2012

Why can't my 21 year old Son have the gastric band fitted when he is over 28 stones and lives in his bedroom all of the time because he is so afraid of what people think of him. Does he have to wait untill he has a heart attack, diabetes or a stroke. He fits all of the criteria and also his mental health now because of the fear of going out of the house. I had the gastric band fitted 7 years ago now and I lost 11 stones and kept it off. I wonder if anyone will respond to this letter?

Report this content as offensive or unsuitable

Online clinic on weight loss

Open now – get expert advice on losing weight, diets, exercise, obesity surgery and other weight loss topics

Lose weight

For a healthy weight, eat well and get active. Find out how to get started and keep going

'Is weight loss surgery right for me?'

Find out whether weight loss surgery, including gastric band and gastric bypass, is right for you, and how it would affect your diet and lifestyle