Introduction to Bariatric (Weight Loss) Surgery

Patient Information Leaflet

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What is this information about?

This leaflet provides information about bariatric (weight loss) surgery.

It explains:

• why treating obesity is important
• what bariatric surgery is
• the different types of surgery
• who may be suitable for surgery
• what life is like after surgery
• what happens next if you are considering treatment.

Why have I been given this information?

You have been given this leaflet because you are considering bariatric (weight loss) surgery or have been referred to a bariatric service.

Weight loss surgery can help improve your health and quality of life if you are living with obesity and obesity-related health conditions.

Why is it important to treat obesity?

Losing weight can have significant health benefits.

A reduction in weight may:

• increase life expectancy by up to 8–10 years
• improve or prevent type 2 diabetes
• lower high blood pressure
• improve sleep apnoea
• improve fertility
• reduce joint pain and improve mobility
• improve overall quality of life.

What is bariatric surgery?

Bariatric surgery, also known as weight loss surgery, is an operation that helps people lose weight when other treatments have not been successful.

The surgery works by helping you eat less, reducing hunger, and in some procedures reducing the amount of food your body absorbs.

Surgery is only one part of treatment. Long-term success depends on following the advice of your bariatric team, including making lifelong changes to your eating habits and lifestyle.

What types of bariatric surgery are available?

Gastric Sleeve

During a gastric sleeve operation, most of the stomach is removed, leaving a much smaller stomach.

This means:

• you eat much smaller meals
• you feel full more quickly
• you feel less hungry because hormones that control appetite are altered. These changes help support long-term weight loss.

Gastric Bypass

During a gastric bypass, a small pouch is created at the top of the stomach.

This pouch is connected to a part of your intestine further down, bypassing the rest of your stomach and the first part of your intestine.

This helps weight loss by:

• reducing the amount of food you can eat
• reducing the amount of food absorbed by your body
• changing hormones that reduce appetite.

Who is suitable for bariatric surgery?

You may be eligible for bariatric surgery on the NHS if:

• you have a Body Mass Index (BMI) of 40 or above, or
• you have a BMI between 35 and 40 and an obesity-related condition that may improve with weight loss, such as:
  • Type 2 diabetes
  • High blood pressure
  • Sleep apnoea

You must also be willing to:

• make lifelong healthy lifestyle changes
• attend regular follow-up appointments
• commit to long-term monitoring after surgery.

What is Body Mass Index (BMI)?

Body Mass Index (BMI) is a measurement that estimates whether your weight is healthy for your height.

It is calculated by dividing your weight (in kilograms) by your height (in metres) squared.

Your healthcare professional can calculate your BMI or advise you how to do this.

What should I expect after bariatric surgery?

Eating and drinking

Your stomach will be much smaller after surgery, so you will need to make permanent changes to how you eat and drink.

Following surgery:

• you will begin with a puréed diet for approximately four weeks.
• foods are gradually reintroduced over the following weeks.
• by around 12 weeks, most people are eating:
  • three small meals each day (approximately side-plate sized)
  • two small healthy snacks

To help your recovery and long-term weight loss you should:

• chew food thoroughly
• eat slowly
• prioritise protein-rich foods such as meat, fish, eggs, beans, lentils, nuts and dairy products
• sip fluids regularly throughout the day
• avoid drinking while eating
• avoid fizzy drinks
• avoid alcohol during the first year after surgery.

Weight loss

Weight loss varies between individuals.

Most people experience:

• rapid weight loss during the first four months
• slower weight loss over the following months
• a more stable weight by around one year.

Your healthcare team will discuss realistic weight-loss expectations with you.

The main aim of surgery is to improve your health, not simply to reduce your weight.

Some people may develop excess skin after significant weight loss. Surgery to remove excess skin is not routinely funded by the NHS.

What commitments will I need to make?

To achieve the best results after surgery, you will need to:

• attend bariatric clinic appointments for the first two years
• have a yearly blood test for lifelong monitoring
• take prescribed vitamin and mineral supplements every day for life.

These supplements are essential because your body may absorb fewer nutrients after surgery. Not taking them can lead to serious health problems.

What happens next?

If you think bariatric surgery may be suitable for you, speak to your GP.

If you meet the NHS eligibility criteria, your GP can refer you to the Bariatric Surgery Service for assessment.

Your specialist team will determine whether surgery is the most appropriate treatment for you.

Not everyone referred will be suitable for surgery.

Before surgery you may be asked to:

• stop smoking
• improve your diabetes control if necessary
• undergo assessment or treatment for sleep apnoea if suspected.

Your healthcare team will explain any preparation required before surgery.

Where can I find further information?

For more information about:

Important

Bariatric surgery is a tool to help with weight loss and improve health. Long-term success depends on lifelong commitment to healthy eating, regular physical activity, vitamin supplementation, and ongoing follow-up with your bariatric team.

This leaflet provides general information and does not replace advice from your healthcare team.