Overweight and obesity management

  • NICE guideline
  • NG246
  • Published: 

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Medicines and surgery

People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

Health and social care professionals should follow our general guidelines for people delivering care:

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1.17 Medicines for overweight and obesity

Medicines for adults

This section contains a table of medicines for weight management, which includes NICE technology appraisal guidance.

1.17.1

After dietary, exercise and behavioural approaches have been started and evaluated in adults living with overweight or obesity, see the weight management medicines options listed in table 1. [2006, amended 2025]

1.17.2

All medicines for weight management should be used alongside a reduced-calorie diet and increased physical activity. [2025]

1.17.3

Make the decision to start medicines after discussing them with the person, and discussing the potential impact on their motivation. Arrange information, support and counselling on additional diet, physical activity and behavioural strategies when medicines are prescribed, and give information on patient support programmes. [2006, amended 2014]

Table 1 Medicines options for weight management in adults
- Tirzepatide Semaglutide Liraglutide Orlistat

For more detail see

NICE's technology appraisal guidance on tirzepatide for managing overweight and obesity (TA1026, December 2024)

NICE's technology appraisal guidance on semaglutide for managing overweight and obesity (TA875, March 2023)

NICE's technology appraisal guidance on liraglutide for managing overweight and obesity (TA664, December 2020)

There is no NICE technology appraisal guidance on orlistat

For adults with

An initial BMI of at least 35 kg/m2 and at least 1 weight-related comorbidity.

At least 1 weight-related comorbidity and:

  • an initial BMI of 35.0 kg/m2 or more,

or

An initial BMI of 35 kg/m2 or more

and

non-diabetic hyperglycaemia

and

a high risk of cardiovascular disease.

A BMI of 30 kg/m2 or more

or

a BMI of 28 kg/m2 or more and associated risk factors. (orlistat summary of product characteristics [SPC])

Setting

Prescribed in primary care or a specialist overweight and obesity management service.

Prescribed in a specialist overweight and obesity management service.

Prescribed in secondary care by a specialist overweight and obesity management service.

Prescribed in all settings and available in a lower dose from a pharmacy.

Route and frequency

Weekly subcutaneous injection.

Weekly subcutaneous injection.

Daily subcutaneous injection.

Oral capsule, up to 3 times a day.

Pregnancy and contraception

Do not use in pregnancy or in women of childbearing potential not using contraception. Switch to a non-oral contraceptive method, or add a barrier method of contraception, for 4 weeks on initiation and after each dose escalation.

(tirzepatide SPC)

Do not use in pregnancy. Women of childbearing potential are recommended to use contraception. (semaglutide SPC)

Do not use in pregnancy. (liraglutide SPC)

Caution in pregnancy.

The use of an additional contraceptive method is recommended to prevent possible failure of oral contraception that could occur in case of severe diarrhoea. (orlistat SPC)

When to stop treatment

If less than 5% of the initial weight has been lost after 6 months on the highest tolerated dose, decide whether to continue treatment, taking into account the benefits and risks of treatment for the person.

Consider stopping if less than 5% of the initial weight has been lost after 6 months of treatment.

Stop after 12 weeks on the 3.0 mg/day dose if at least 5% of the initial body weight has not been lost.

(liraglutide SPC)

Stop after 12 weeks if at least 5% of the initial body weight has not been lost.

(orlistat SPC)

Semaglutide and liraglutide are recommended for use within specialist weight management services, which are usually accessed for up to 2 years.

For tirzepatide, semaglutide and liraglutide, use lower BMI thresholds (usually reduced by 2.5 kg/m2) for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean ethnic backgrounds.

Non-diabetic hyperglycaemia is defined as a haemoglobin A1c level of 42 mmol/mol to 47 mmol/mol (6.0% to 6.4%) or a fasting plasma glucose level of 5.5 mmol/litre to 6.9 mmol/litre.

Continued prescribing and withdrawal for adults
1.17.4

If there is concern about micronutrient intake adequacy, consider a supplement providing the reference nutrient intake for all vitamins and minerals, particularly for older people (who may be at risk of malnutrition) and young people (who need vitamins and minerals for growth and development). [2006]

1.17.5

Offer support to help maintain weight loss to people who are stopping weight management medicines. [2006]

Monitoring weight management medicines in adults
1.17.6

Monitor the effect of medicines and reinforce behavioural advice and adherence through regular review. [2006, amended 2014]

1.17.7

When agreeing goals with someone with type 2 diabetes, take into account that their weight loss may be slower than that of people without the condition. Review their goals regularly. [2006]

Medicines for children and young people

1.17.8

Weight management medicines are not generally recommended for children younger than 12 years. [2006]

1.17.10

In children aged 12 years and older, treatment with orlistat is recommended only if physical comorbidities (such as orthopaedic problems or sleep apnoea) or severe psychological comorbidities are present, and if started in a specialist paediatric setting by a multidisciplinary team with expertise in:

  • prescribing in this age group

  • monitoring medicines

  • psychological support

  • behavioural interventions

  • interventions to increase physical activity

  • interventions to improve dietary intake. [2006, amended 2014]

    In June 2023, this was an off-label use of orlistat. See NICE's information on prescribing medicines.

1.17.11

Medicines may be continued in primary care, for example with a shared-care protocol, if local circumstances or licensing allow. [2006, amended 2014]

Continued prescribing and withdrawal for children and young people
1.17.13

If orlistat is prescribed for children and young people, a 6- to 12‑month trial is recommended, with regular review to assess effectiveness, adverse effects and adherence.

In June 2023, this was an off-label use of orlistat. See NICE's information on prescribing medicines. [2006, amended 2014]

1.18 Surgical interventions

Also see NICE's interventional procedures guidance on endoscopic sleeve gastroplasty for obesity.

When to refer adults for assessment for bariatric surgery

1.18.1

Offer adults a referral for a comprehensive assessment by specialist overweight and obesity management services providing multidisciplinary management of obesity, to see whether bariatric surgery is suitable for them if they:

  • have a BMI of 40 kg/m2 or more, or between 35 kg/m2 and 39.9 kg/m2 with a significant health condition that could be improved if they lost weight (see box 2 for examples) and

  • agree to the necessary long-term follow up after surgery (for example, lifelong annual reviews). [2023]

1.18.2

Consider referral for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African–Caribbean background using a lower BMI threshold (reduced by 2.5 kg/m2) than in recommendation 1.9.1, to account for the fact that these groups are prone to central adiposity and their cardiometabolic risk occurs at lower BMI. [2023]

Box 2 Examples of common health conditions that can improve after bariatric surgery

Some conditions that can improve after bariatric surgery include:

  • cardiovascular disease

  • hypertension

  • idiopathic intracranial hypertension

  • non-alcoholic fatty liver disease with or without steatohepatitis

  • obstructive sleep apnoea

  • type 2 diabetes.

These examples are based on the evidence identified for this guideline and the list is not exhaustive.

When to offer expedited assessment

1.18.3

Offer an expedited assessment for bariatric surgery to people:

  • with a BMI of 35 kg/m2 or more who have recent-onset (diagnosed within the past 10 years) type 2 diabetes and

  • as long as they are also receiving, or will receive, assessment in a specialist overweight and obesity management service. [2014]

1.18.4

Consider an expedited assessment for bariatric surgery for people:

  • with a BMI of 30 to 34.9 kg/m2 who have recent-onset (diagnosed within the past 10 years) type 2 diabetes and

  • who are also receiving, or will receive, assessment in a specialist overweight and obesity management service. [2014]

1.18.5

Consider an expedited assessment for bariatric surgery for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African–Caribbean background using a lower BMI threshold (reduced by 2.5 kg/m2) than in recommendation 1.9.4, to account for the fact that these groups are prone to central adiposity and their cardiometabolic risk occurs at lower BMI. [2014, amended 2023]

Initial assessment and discussions with the multidisciplinary team

1.18.6

Ensure the multidisciplinary team within a specialist overweight and obesity management service includes or has access to health and social care professionals who have expertise in conducting medical, nutritional, psychological and surgical assessments in people living with obesity and are able to assess whether surgery is suitable. [2023]

1.18.7

Carry out a comprehensive, multidisciplinary assessment for bariatric surgery based on the person's needs. As part of this, assess:

  • the person's medical needs (for example, existing comorbidities)

  • their nutritional status (for example, dietary intake, and eating behaviours)

  • any psychological needs that, if addressed, would help ensure surgery is suitable and support adherence to postoperative care requirements

  • their previous attempts to manage their weight, and any past response to an overweight and obesity management intervention (such as one provided by a specialist overweight and obesity management service)

  • any other factors that may affect their response after surgery (for example, language barriers, learning disabilities and neurodevelopmental conditions, deprivation and other factors related to health inequalities)

  • whether any individual arrangements need to be made before the day of the surgery (for example if they need extra dietary or psychological support, or support to manage existing or new comorbidities)

  • fitness for anaesthesia and surgery. [2023]

1.18.8

The hospital specialist or bariatric surgeon should discuss the following with people who are thinking about having bariatric surgery:

  • the potential benefits

  • plans for conception and pregnancy (for women and trans and non-binary people of childbearing age)

  • the longer-term implications and requirements of surgery

  • the potential risks, including perioperative mortality, and complications.

    Include the person's family and carers in the discussion, if appropriate. [2006, amended 2023]

1.18.9

Choose the surgical intervention jointly with the person, taking into account:

  • the severity of obesity and any comorbidities

  • the best available evidence on effectiveness and long-term effects

  • the facilities and equipment available

  • the experience of the surgeon who would perform the operation. [2006]

1.18.10

Give the person information on:

  • appropriate dietary intake after the bariatric procedure

  • monitoring their macronutrient and micronutrient status

  • individualised nutritional supplementation, and sources of support and guidance for long-term weight loss and weight maintenance

  • patient support groups. [2006, amended 2023]

For a short explanation of why the committee made the 2023 recommendations and how they might affect practice, see the .

Full details of the evidence and the committee's discussion are in evidence review CG189 C: referral for bariatric surgery.

Preoperative assessment and discussions

1.18.11

Carry out a comprehensive preoperative assessment of any psychological or clinical factors that may affect adherence to postoperative care requirements (such as changes to dietary intake, eating behaviours and taking nutritional supplements) before performing surgery. [2006, amended 2014]

Medicines while waiting for surgery

Multidisciplinary team qualifications and hospital equipment in surgical settings

1.18.13

The surgeon in the multidisciplinary team should have:

  • had relevant, supervised training

  • specialist experience in bariatric surgery. [2006, amended 2014]

1.18.14

Ensure the multidisciplinary team carrying out bariatric surgery can provide:

  • preoperative assessment, including a risk-benefit analysis that includes preventing complications of obesity

  • specialist assessment for eating disorders (and if appropriate, referral or signposting to specialist eating disorder services)

  • information on the different procedures, including potential weight loss and possible risks

  • regular postoperative assessment, including specialist dietetic and surgical follow up (see recommendation 1.18.17 on postoperative and longer-term follow-up care)

  • management of comorbidities

  • specialist psychological support before and after surgery (for example, a psychological assessment before surgery and, if appropriate, referral to specialist mental health services either before or after surgery)

  • information on plastic surgery (such as apronectomy) if appropriate. [2006, amended 2023]

1.18.15

Hospitals undertaking bariatric surgery should ensure there is access to, and staff trained to use, suitable equipment, including but not limited to weighing scales, blood pressure cuffs, theatre tables, walking frames, commodes, hoists, bed frames, pressure-relieving mattresses and seating suitable for people having bariatric surgery. [2006, amended 2023]

1.18.16

Only surgeons with extensive experience should undertake revisional surgery (if the first operation has not been effective) in specialist centres because of the higher rate of complications and increased mortality of revision surgery compared with primary surgery. [2006]

Postoperative and longer-term follow-up care

1.18.17

Offer people who have had bariatric surgery a follow-up care package for a minimum of 2 years within the bariatric service. Include:

  • monitoring nutritional intake, (including protein and vitamins) and mineral deficiencies

  • monitoring for comorbidities

  • medications review

  • individualised dietary and nutritional assessment, advice and support

  • advice and support on physical activity

  • psychological support tailored to the person

  • information about professionally led or peer-support groups. [2014]

1.18.18

After discharge from follow up by the bariatric surgery service, ensure people are offered at least annual monitoring of nutritional status and appropriate supplementation after bariatric surgery, as part of a shared-care model with primary care. [2014]

Audit of bariatric surgery

1.18.19

Arrange a prospective audit so that the outcomes and complications of different procedures, the impact on quality of life and nutritional status, and the effect on comorbidities can be monitored in both the short and the long term. (The National Bariatric Surgery Registry conducts national audits for agreed outcomes.) [2006, amended 2014]

1.18.20

The surgeon in the multidisciplinary team should submit data for a national clinical audit scheme such as the National Bariatric Surgery Registry. [2006, amended 2014]

Surgery for children and young people

1.18.21

Surgery for obesity is not generally recommended in children or young people. [2006]

1.18.22

Surgery for obesity may be considered for young people only in exceptional circumstances, and if they have achieved or nearly achieved physiological maturity. [2006]

1.18.23

Surgery for obesity should be undertaken only by a multidisciplinary team that can provide paediatric expertise in:

  • preoperative assessment, including a risk-benefit analysis that includes preventing complications of obesity

  • specialist assessment for eating disorders (and, if appropriate, referral or signposting to specialist eating disorder services)

  • information on the different procedures, including potential weight loss and possible risks

  • regular postoperative assessment, including specialist dietetic and surgical follow up (see recommendation 1.18.17 on postoperative and longer-term follow-up care)

  • management of comorbidities

  • specialist psychological support before and after surgery (for example, a psychological assessment before surgery and, if appropriate, referral to specialist mental health services either before or after surgery)

  • information on plastic surgery (such as apronectomy) if appropriate. [2006, amended 2023]

1.18.24

Hospitals undertaking paediatric bariatric surgery should ensure there is access to, and staff trained to use suitable equipment, including scales, theatre tables, walking frames, commodes, hoists, bed frames, pressure-relieving mattresses and seating suitable for young people having bariatric surgery. [2006, amended 2023]

1.18.26

Ensure all young people have had a comprehensive psychological, educational, family and social assessment before undergoing bariatric surgery. [2006, amended 2014]

1.18.27

Perform a full medical evaluation, including genetic screening or assessment before surgery to exclude rare, treatable causes of obesity. [2006]