Obesity: identification, assessment and management

This guideline covers identifying, assessing and managing obesity in children (aged 2 years and over), young people and adults.

# Recommendations
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.

# Generic principles of care

## Adults
Equip specialist settings for treating people who are living with severe obesity with, for example, special seating and adequate weighing and monitoring equipment. Ensure hospitals have access to specialist equipment  such as larger scanners and beds  when providing general care for people who are living with severe obesity. 
Discuss the choice of interventions for weight management with the person. The choice of intervention should be agreed with the person. 
Tailor the components of the planned weight management programme to the person's preferences, initial fitness, health status and lifestyle. 

## Children
Coordinate the care of children and young people around their individual and family needs. Comply with the approaches outlined in the Department of Health's A call to action on obesity in England. See also NICE's guideline on weight management: lifestyle services for overweight or obese children and young people. 
Aim to create a supportive environment that helps a child who is overweight or who has obesity, and their family, make lifestyle changes. (The committee noted that 'environment' could include settings other than the home, for example, schools.) 
Make decisions about the care of a child who is overweight or has obesity (including assessment and agreeing goals and actions) together with the child and family. Tailor interventions to the needs and preferences of the child and the family. 
Ensure that interventions for children who are living with overweight or obesity address lifestyle within the family and in social settings. 
Encourage parents (or carers) to take main responsibility for lifestyle changes in children who are living with overweight or obesity, especially if they are younger than 12 years. Take into account the age and maturity of the child, and the preferences of the child and the parents. 

## Adults and children
Offer regular, non-discriminatory long-term follow-up by a trained professional. Ensure continuity of care in the multidisciplinary team through good record keeping. 

# Identifying and assessing overweight, obesity and central adiposity

## Identification and assessment in adults
Use clinical judgement to decide when to measure a person's height and weight. Opportunities include when registering with a GP, consultations for related conditions (such as type 2 diabetes and cardiovascular disease) and other routine health checks. 
Encourage adults with a body mass index (BMI) below 35 kg/m2 to:
measure their own waist-to-height ratio to assess central adiposity (the accumulation of excess fat in the abdominal area)
seek advice and further clinical assessments (such as a cardiometabolic risk factor assessment) from a healthcare professional if the measurement indicates an increased health risk. Explain to people that to accurately measure their waist and calculate their own waist-to-height ratio, they should follow the advice in box 1. 
Direct people to resources that give advice on how to measure waist circumference, such as the NHS BMI healthy weight calculator. See recommendations 1.2.11 and 1.2.12 for how to interpret waist-to-height ratio. 
Measure
Find the bottom of the ribs and the top of the hips.
Wrap a tape measure around the waist midway between these points (this will be just above the belly button) and breathe out naturally before taking the measurement.
Calculate
Measure waist circumference and height in the same units (either both in centimetres, or both in inches). If you know your height in feet and inches, convert it to inches (for example, 5 feet 7 inches is 67 inches).
Divide waist measurement by height measurement. For example:
inches divided by 67 inches = waist-to-height ratio of 0.57 or
cm divided by 170 cm = waist-to-height ratio of 0.57.
Use BMI as a practical measure of overweight and obesity. Interpret it with caution because it is not a direct measure of central adiposity. 
In adults with BMI below 35 kg/m2, measure and use their waist-to-height ratio, as well as their BMI, as a practical estimate of central adiposity and use these measurements to help to assess and predict health risks (for example, type 2 diabetes, hypertension or cardiovascular disease). 
Do not use bioimpedance as a substitute for BMI as a measure of general adiposity in adults. 
Define the degree of overweight or obesity in adults as follows, if they are not in the groups covered by recommendation 1.2.8:
healthy weight: BMI 18.5 kg/m2 to 24.9 kg/m2
-verweight: BMI 25 kg/m2 to 29.9 kg/m2
-besity class 1: BMI 30 kg/m2 to 34.9 kg/m2
-besity class 2: BMI 35 kg/m2 to 39.9 kg/m2
-besity class 3: BMI 40 kg/m2 or more. Use clinical judgement when interpreting the healthy weight category because a person in this category may nevertheless have central adiposity. See Public Health England's guidance on obesity and weight management for people with learning disabilities for information on reasonable adjustments that may need to be made. 
People with a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background are prone to central adiposity and their cardiometabolic risk occurs at lower BMI, so use lower BMI thresholds as a practical measure of overweight and obesity:
-verweight: BMI 23 kg/m2 to 27.4 kg/m2
-besity: BMI 27.5 kg/m2 or above. For people in these groups, obesity classes 2 and 3 are usually identified by reducing the thresholds highlighted in recommendation 1.2.7 by 2.5 kg/m2. 
Interpret BMI with caution in adults with high muscle mass because it may be a less accurate measure of central adiposity in this group. 
Interpret BMI with caution in people aged 65 and over, taking into account comorbidities, conditions that may affect functional capacity and the possible protective effect of having a slightly higher BMI when older. 
Define the degree of central adiposity based on waist-to-height ratio as follows:
healthy central adiposity: waist-to-height ratio 0.4 to 0.49, indicating no increased health risks
increased central adiposity: waist-to-height ratio 0.5 to 0.59, indicating increased health risks
high central adiposity: waist-to-height ratio 0.6 or more, indicating further increased health risks. These classifications can be used for people with a BMI under 35 kg/m2 of both sexes and all ethnicities, including adults with high muscle mass. The health risks associated with higher levels of central adiposity include type 2 diabetes, hypertension and cardiovascular disease. 
When talking to a person about their waist-to-height ratio, explain that they should try and keep their waist to half their height (so a waist-to-height ratio of under 0.5). 
Ask the person's permission before talking about the degree of overweight, obesity and central adiposity, and discuss it in a sensitive manner. 
Give adults information about the severity of their overweight or obesity and central adiposity and the impact this has on their risk of developing other long-term conditions (such as type 2 diabetes, cardiovascular disease, hypertension, dyslipidaemia, certain cancers and respiratory, musculoskeletal and other metabolic conditions such as non-alcoholic fatty liver disease). 
Discuss and agree the level of intervention with adults who:
are living with overweight or obesity or
have increased health risk based on their waist-to-height ratio.Take into account people's individual needs and preferences, and factors such as weight-related comorbidities, ethnicity, socioeconomic status, family medical history, and special educational needs and disabilities (SEND). See the recommendations on lifestyle interventions, behavioural interventions, physical activity, dietary approaches, pharmacological interventions and surgical interventions. 
Offer a higher level of intervention to people with weight-related comorbidities (see recommendation 1.3.6 for details of comorbidities). Adjust the approach depending on the person's clinical needs. For people with a BMI over 35 kg/m2 who have recently developed diabetes, see recommendation 1.11.1, and for people with a BMI of 50 and over, see recommendation 1.3.7 and recommendation 1.10.7. 
For a short explanation of why the committee made the 2022 recommendations and how they might affect practice, see the rationale and impact section on identifying and assessing overweight, obesity and central adiposity in adults .
Full details of the evidence and the committee's discussion are in evidence review A: accuracy of anthropometric measures in assessing health risks associated with overweight and obesity in adults.
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Ensure healthcare professionals are aware that people from Black, Asian and minority ethnic family backgrounds are at an increased risk of chronic health conditions at a lower BMI than people from a white family background (below BMI 25 kg/m2). 
Ensure people from Black, Asian and minority ethnic family backgrounds are aware that they face an increased risk of chronic health conditions at a lower BMI than people from a white family background (below BMI 25 kg/m2). 
Use existing local information networks for people of Black and minority ethnic family backgrounds to share information on the increased risks these groups face at a lower BMI. 

## Identification and assessment in children and young people
Use clinical judgement to decide when to measure a child or young person's height and weight. Opportunities include when registering with a GP, consultations for related conditions (such as type 2 diabetes and cardiovascular disease) and other routine health checks. 
Use BMI as a practical estimate of overweight and obesity, and ensure that charts used are:
appropriate for children and young people and
adjusted for age and sex. Interpret BMI with caution because it is not a direct measure of central adiposity. The Royal College of Paediatrics and Child Health UK-World Health Organization (WHO) growth charts and BMI charts should be used to plot and classify BMI centile. The childhood and puberty close monitoring (CPCM) form can also be used for continued BMI monitoring in children aged 2 and over, especially in instances where puberty is either premature or delayed. Refer to special BMI growth charts for children and young people with Down's syndrome, if needed. 
Consider using waist-to-height ratio in children and young people aged 5 and over to assess and predict health risks associated with central adiposity (such as type 2 diabetes, hypertension or cardiovascular disease). See box 1 for information on how the waist should be measured and how to calculate waist-to-height ratio. 
Do not use bioimpedance as a substitute for BMI as a measure of general adiposity in children and young people. 
Define the degree of overweight or obesity in children and young people using the following classifications:
-verweight: BMI 91st centile + 1.34 standard deviations (SDs)
clinical obesity: BMI 98th centile + 2.05 SDs
severe obesity: BMI 99.6th centile + 2.68 SDs. Use clinical judgement when interpreting BMI below the 91st centile, especially the healthy weight category in BMI charts because a child or young person in this category may nevertheless have central adiposity. 
Define the degree of central adiposity based on waist-to-height ratio in children and young people as follows:
healthy central adiposity: waist-to-height ratio 0.4 to 0.49, indicating no increased health risk
increased central adiposity: waist-to-height ratio 0.5 to 0.59, indicating increased health risk
high central adiposity: waist-to-height ratio 0.6 or more, indicating further increased health risk. These classifications can be used for children and young people of both sexes and all ethnicities. The health risks associated with higher central adiposity levels include type 2 diabetes, hypertension and cardiovascular disease. 
When talking to a child, young person, and their families and carers, explain that they should try and keep their waist to half their height (so a waist-to-height-ratio of under 0.5). 
Ask permission from children, young people, and their families and carers, before talking about the degree of overweight, obesity and central adiposity, and discuss it in a sensitive and age-appropriate manner. 
Consider tailored interventions for children and young people:
who are living with overweight or obesity or
have increased health risk based on their waist-to-height ratio. Take into account their individual needs and preferences, and factors such as weight-related comorbidities, ethnicity, socioeconomic status, social complexity (for example, looked-after children and young people), family medical history, mental and emotional health and wellbeing, developmental age, and special educational needs and disabilities (SEND). See the recommendations on lifestyle interventions, behavioural interventions, physical activity, dietary approaches, pharmacological interventions and surgical interventions. 
Offer a higher level of intervention to children with weight-related comorbidities (see recommendation 1.3.9 for details of comorbidities). Adjust the approach depending on the child's clinical needs. For pharmacological treatment in children with comorbidities, see recommendations 1.8.5 and 1.8.6 and for surgical interventions in young people with exceptional circumstances, see recommendations 1.10.12 and 1.10.13. 
For a short explanation of why the committee made the 2022 recommendations and how they might affect practice, see the rationale and impact section on identifying and assessing overweight, obesity and central adiposity in children and young people .
Full details of the evidence and the committee's discussion are in evidence review B: accuracy of anthropometric measures in assessing health risks associated with overweight and obesity in children and young people.
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# Assessment

## Adults and children
Make an initial assessment (see recommendations 1.3.6 and 1.3.8), then use clinical judgement to investigate comorbidities and other factors to an appropriate level of detail, depending on the person, the timing of the assessment, the degree of overweight or obesity, and the results of previous assessments. 
Manage comorbidities when they are identified; do not wait until the person has lost weight. 
Offer people who are not yet ready to change the chance to return for further consultations when they are ready to discuss their weight again and willing or able to make lifestyle changes. Give them information on the benefits of losing weight, healthy eating and increased physical activity. 
Recognise that surprise, anger, denial or disbelief about their health situation may diminish people's ability or willingness to change. Stress that obesity is a clinical term with specific health implications, rather than a question of how people look; this may reduce any negative feelings.During the consultation:
Assess the person's view of their weight and the diagnosis, and possible reasons for weight gain.
Explore eating patterns and physical activity levels.
Explore any beliefs about eating, physical activity and weight gain that are unhelpful if the person wants to lose weight.
Be aware that people from certain ethnic and socioeconomic backgrounds may be at greater risk of obesity, and may have different beliefs about what is a healthy weight and different attitudes towards weight management.
Find out what the person has already tried and how successful this has been, and what they learned from the experience.
Assess the person's readiness to adopt changes.
Assess the person's confidence in making changes. 
Give people and their families and/or carers information on the reasons for tests, how the tests are done, and their results and meaning. If necessary, offer another consultation to fully explore the options for treatment or discuss test results. 

## Adults
Take measurements (see section 1.2) to determine degree of overweight or obesity and discuss the implications of the person's weight. Then, assess:
any presenting symptoms
any underlying causes of overweight or obesity
eating behaviours
any comorbidities (for example type 2 diabetes, hypertension, cardiovascular disease, osteoarthritis, dyslipidaemia and sleep apnoea)
any risk factors assessed using lipid profile (preferably done when fasting), blood pressure measurement and HbA1c measurement
the person's lifestyle (diet and physical activity)
any psychosocial distress
any environmental, social and family factors, including family history of overweight and obesity and comorbidities
the person's willingness and motivation to change lifestyle
the potential of weight loss to improve health
any psychological problems
any medical problems and medication
the role of family and care workers in supporting individuals with learning disabilities to make lifestyle changes.See also NICE's guideline on weight management: lifestyle services for overweight or obese children and young people. 
Consider referral to tier 3 services if:
the underlying causes of overweight or obesity need to be assessed
the person has complex disease states or needs that cannot be managed adequately in tier 2 (for example, the additional support needs of people with learning disabilities)
conventional treatment has been unsuccessful
drug treatment is being considered for a person with a BMI of more than 50 kg/m2
specialist interventions (such as a very-low-calorie diet) may be needed
surgery is being considered. For more information on tier 3 services, see NHS England's report on joined up clinical pathways for obesity. 

## Children
Assessment of comorbidity should be considered for children with a BMI at or above the 98th centile. 
Take measurements to determine degree of overweight or obesity and raise the issue of weight with the child and family, then assess:
presenting symptoms and underlying causes of overweight or obesity
willingness and motivation to change
comorbidities (such as hypertension, hyperinsulinaemia, dyslipidaemia, type 2 diabetes, psychosocial dysfunction and exacerbation of conditions such as asthma)
any risk factors assessed using lipid profile (preferably done when fasting) blood pressure measurement and HbA1c measurement
psychosocial distress, such as low self-esteem, teasing and bullying (See also NICE's guideline on weight management: lifestyle services for overweight or obese children and young people)
family history of overweight or obesity and comorbidities
the child and family's willingness and motivation to change lifestyle
lifestyle (diet and physical activity)
environmental, social and family factors that may contribute to overweight or obesity, and the success of treatment
growth and pubertal status
any medical problems and medication
the role of family and care workers in supporting people with learning disabilities to make lifestyle changes. 
Consider referral to an appropriate specialist for children who are living with overweight or obesity and have significant comorbidities or complex needs (for example, learning disabilities or other additional support needs). 
In tier 3 services, assess associated comorbidities and possible causes for children and young people who are living with overweight or obesity. Use investigations such as:
blood pressure measurement
lipid profile, preferably while fasting
fasting insulin
fasting glucose levels and oral glucose tolerance test
liver function
endocrine function.Interpret the results of any tests used in the context of how the level of the child's overweight or obesity is, the child's age, history of comorbidities, possible genetic causes and any family history of metabolic disease related to overweight or obesity. 
Make arrangements for transitional care for children and young people who are moving from paediatric to adult services. 

# Lifestyle interventions

## Adults and children
Multicomponent interventions are the treatment of choice. Ensure weight management programmes include behaviour change strategies (see recommendations 1.5.1 to 1.5.3) to increase people's physical activity levels or decrease inactivity, improve eating behaviour and the quality of the person's diet, and reduce energy intake. 
When choosing treatments, take into account:
the person's individual preference and social circumstance and the experience and outcome of previous treatments (including whether there were any barriers)
the person's degree of overweight and obesity or increased health risk based on their waist-to-height ratio (see recommendations 1.2.11 and 1.2.15)
any comorbidities. 
Document the results of any discussion. Keep a copy of the agreed goals and actions (ensure the person also does this), or put this in the person's notes. 
Offer support depending on the person's needs, and be responsive to changes over time. 
Ensure any healthcare professionals who deliver interventions for weight management have relevant competencies and have had specific training. 
Provide information in formats and languages that are suited to the person. Use everyday, jargonfree language and explain any technical terms when talking to the person and their family or carers. Take into account the person's:
age and stage of life
gender
cultural needs and sensitivities
ethnicity
social and economic circumstances
specific communication needs (for example because of learning disabilities, physical disabilities or cognitive impairments due to neurological conditions). 
Praise successes  however small  at every opportunity to encourage the person through the difficult process of changing established behaviour. 
Give people who are living with overweight or obesity, and their families and/or carers, relevant information on:
being overweight and obesity in general, including related health risks
realistic targets for weight loss; for adults, see NICE's guideline on managing overweight and obesity in adults
the distinction between losing weight and maintaining weight loss, and the importance of developing skills for both; advise them that the change from losing weight to maintenance typically happens after 6 to 9 months of treatment
realistic targets for outcomes other than weight loss, such as increased physical activity and healthier eating
diagnosis and treatment options
healthy eating in general (more information on healthy eating can be found on the eat well pages of the NHS website)
medication and side effects
surgical treatments
self-care
voluntary organisations and support groups and how to contact them.Ensure there is adequate time in the consultation to provide information and answer questions. 
If a person (or their family or carers) does not feel this is the right time for them to take action, explain that advice and support will be available in the future whenever they need it. Provide contact details so that the person can get in touch when they are ready. 

## Adults
Encourage the person's partner or spouse to support any weight management programme. 
Base the level of intensity of the intervention on the level of risk and the potential to gain health benefits (see recommendations 1.2.15 and 1.2.16). 

## Children
Be aware that the aim of weight management programmes for children and young people can vary. The focus may be on either weight maintenance or weight loss, depending on the person's age and stage of growth. 
Encourage parents of children and young people who are living with overweight or obesity to lose weight if they are also living with overweight or obesity. 

# Behavioural interventions

## Adults and children
Deliver any behavioural intervention with the support of an appropriately trained professional. 

## Adults
Include the following strategies in behavioural interventions for adults, as appropriate:
self-monitoring of behaviour and progress
stimulus control
goal setting
slowing rate of eating
ensuring social support
problem solving
assertiveness
cognitive restructuring (modifying thoughts)
reinforcement of changes
relapse prevention
strategies for dealing with weight regain. 

## Children
Include the following strategies in behavioural interventions for children, as appropriate:
stimulus control
self-monitoring
goal setting
rewards for reaching goals
problem solving.Give praise to successes and encourage parents to role-model desired behaviours. 

# Physical activity

## Adults
Encourage adults to increase their level of physical activity even if they do not lose weight as a result, because of the other health benefits it can bring (for example, reduced risk of type 2 diabetes and cardiovascular disease). Encourage adults to meet the recommendations in the UK Chief Medical Officers' physical activity guidelines for weekly activity. 
Advise that to prevent obesity, most people may need to do 45 to 60 minutes of moderate-intensity activity a day, particularly if they do not reduce their energy intake. Advise people who have been living with obesity and have lost weight that they may need to do 60 to 90 minutes of activity a day to avoid regaining weight. 
Encourage adults to build up to the recommended activity levels for weight maintenance, using a managed approach with agreed goals. Recommend types of physical activity, including:
activities that can be incorporated into everyday life, such as brisk walking, gardening or cycling (see also NICE's guideline on walking and cycling)
supervised exercise programmes
-ther activities, such as swimming, aiming to walk a certain number of steps each day, or stair climbing.Take into account the person's current physical fitness and ability for all activities. Encourage people to also reduce the amount of time they spend inactive, such as watching television, using a computer or playing video games. 

## Children
Encourage children and young people to increase their level of physical activity, even if they do not lose weight as a result, because of the other health benefits exercise can bring (for example, reduced risk of type 2 diabetes and cardiovascular disease). Encourage children to meet the recommendations in the UK Chief Medical Officers' physical activity guidelines for daily activity. 
Be aware that children who are already living with overweight may need to do more than 60 minutes' activity. 
Encourage children to reduce inactive behaviours, such as sitting and watching television, using a computer or playing video games. 
Give children the opportunity and support to do more exercise in their daily lives (for example, walking, cycling, using the stairs and active play; see also NICE's guideline on walking and cycling). Make the choice of activity with the child, and ensure it is appropriate to the child's ability and confidence. 
Give children the opportunity and support to do more regular, structured physical activity (for example football, swimming or dancing). Make the choice of activity with the child, and ensure it is appropriate to the child's ability and confidence. 

# Dietary approaches

## Adults and children
Tailor dietary changes to food preferences and allow for a flexible and individual approach to reducing calorie intake. 
Do not use unduly restrictive and nutritionally unbalanced diets, because they are ineffective in the long term and can be harmful. 
Encourage people to improve their diet even if they do not lose weight, because there can be other health benefits. 

## Adults
The main requirement of a dietary approach to weight loss is that total energy intake should be less than energy expenditure. 
Diets that have a 600 kcal/day deficit (that is, they contain 600 kcal less than the person needs to stay the same weight) or that reduce calories by lowering the fat content (low-fat diets), in combination with expert support and intensive followup, are recommended for sustainable weight loss. 
Consider low-calorie diets (800 to 1600 kcal/day), but be aware these are less likely to be nutritionally complete. 
Do not routinely use very-low-calorie diets (800 kcal/day or less) to manage obesity. 
Only consider very-low-calorie diets, as part of a multicomponent weight management strategy, for people who are living with obesity and who have a clinically assessed need to rapidly lose weight (for example, people who need joint replacement surgery or who are seeking fertility services). Ensure that:
the diet is nutritionally complete
the diet is followed for a maximum of 12 weeks (continuously or intermittently)
the person following the diet is given ongoing clinical support. 
Before starting someone on a very-low-calorie diet as part of a multicomponent weight management strategy:
Consider counselling and assess for eating disorders or other psychopathology to make sure the diet is appropriate for them.
Discuss the risks and benefits with them.
Tell them that this is not a long-term weight management strategy, and that regaining weight may happen and is not because of their own or their clinician's failure.
Discuss the reintroduction of food following a liquid diet with them. 
Provide a long-term multicomponent strategy to help the person maintain their weight after the use of a very-low-calorie diet. (See recommendation 1.4.1.) 
Encourage people to eat a balanced diet in the long term, consistent with other healthy eating advice.More information on healthy eating can be found on the eat well pages of the NHS website. 

## Children
A dietary approach alone is not recommended. It is essential that any dietary recommendations are part of a multicomponent intervention. 
Any dietary changes should be age appropriate and consistent with healthy eating advice. 
For children and young people living with overweight or obesity, total energy intake should be below their energy expenditure. Changes should be sustainable. 

# Pharmacological interventions

## Adults
Consider pharmacological treatment (see table 1) only after dietary, exercise and behavioural approaches have been started and evaluated. NICE has not recommended naltrexonebupropion, see NICE's technology appraisal guidance on naltrexonebupropion for managing overweight and obesity.  
Consider drug treatment (see table 1) for people who have not reached their target weight loss or have reached a plateau on dietary, activity and behavioural changes. 
Make the decision to start drug treatments after discussing the potential benefits and limitations with the person, including the mode of action, adverse effects and monitoring requirements, and the potential impact on the person's motivation. Make arrangements for appropriate healthcare professionals to offer information, support and counselling on additional diet, physical activity and behavioural strategies when drug treatment is prescribed. Provide information on patient support programmes. 
Medicine
Starting criteria
Stopping criteria
Liraglutide, see NICE's technology appraisal guidance on liraglutide for managing overweight and obesity
BMI of:
at least 35 kg/m2 or
at least 32.5 kg/m2 for members of minority ethnic groups known to be at equivalent risk of the consequences of obesity at a lower BMI than the white populationandNon-diabetic hyperglycaemia (haemoglobin A1c level of 42 mmol/mol to 47 mmol/mol  or a fasting plasma glucose level of 5.5 mmol/litre to 6.9 mmol/litre) andHigh risk of cardiovascular disease based on risk factors such as hypertension and dyslipidaemia andPrescribe in secondary care by a specialist weight management serviceandThe company provides it according to the commercial arrangement.
Orlistat
BMI of:
kg/m2 or more or
kg/m2 or more with associated risk factors.Use with other drugs aimed at weight reduction is not recommended.
Continue beyond 3 months only if the person has lost at least 5% of their initial body weight since starting orlistat. (See also recommendation 1.9.6 for people with type 2 diabetes.)
Semaglutide, see NICE's technology appraisal guidance on semaglutide for managing overweight and obesity
BMI of:
at least 35.0 kg/m2 or
kg/m2 to 34.9 kg/m2 and meet the criteria for referral to specialist weight management services in recommendation 1.3.7.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 family backgroundsandAt least 1 weight-related comorbidityandUse within a specialist weight management service.
Consider stopping if less than 5% of the initial weight has been lost after 6 months.
Use for a maximum of 2 years.

## Children
Drug treatment is not generally recommended for children younger than 12 years. 
In children younger than 12 years, drug treatment may be used only in exceptional circumstances, if severe comorbidities are present. Prescribing should be started and monitored only in specialist paediatric settings. 
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. Treatment should be started in a specialist paediatric setting, by multidisciplinary teams with experience of prescribing in this age group. In October 2014, this was an off-label use of orlistat. See NICE's information on prescribing medicines. 
Do not give orlistat to children for obesity unless prescribed by a multidisciplinary team with expertise in:
drug monitoring
psychological support
behavioural interventions
interventions to increase physical activity
interventions to improve diet. 
Drug treatment may be continued in primary care for example with a shared care protocol if local circumstances and/or licensing allow. 

# Continued prescribing and withdrawal

## Adults and children
Pharmacological treatment may be used to maintain weight loss rather than to continue to lose weight. 
If there is concern about micronutrient intake adequacy, a supplement providing the reference nutrient intake for all vitamins and minerals should be considered, particularly for vulnerable groups such as older people (who may be at risk of malnutrition) and young people (who need vitamins and minerals for growth and development). 
Offer support to help maintain weight loss to people whose drug treatment is being withdrawn; if they did not reach their target weight, their self-confidence and belief in their ability to make changes may be low. 

## Adults
Monitor the effect of drug treatment and reinforce lifestyle advice and adherence through regular review. 
Consider withdrawing drug treatment in people who have not reached weight loss targets (see recommendation 1.9.8 and table 1 for details). 
Rates of weight loss may be slower in people with type 2 diabetes, so less strict goals than those for people without diabetes may be appropriate. Agree the goals with the person and review them regularly. 
Only prescribe orlistat as part of an overall plan for managing obesity in adults who meet 1 of the following criteria:
a BMI of 28 kg/m2 or more with associated risk factors
a BMI of 30 kg/m2 or more. 
Continue orlistat therapy beyond 3 months only if the person has lost at least 5% of their initial body weight since starting drug treatment. (See also recommendation 1.9.6 for advice on targets for people with type 2 diabetes.) 
Make the decision to use drug treatment for longer than 12 months (usually for weight maintenance) after discussing potential benefits and limitations with the person. 
The co-prescribing of orlistat with other drugs aimed at weight reduction is not recommended. 

## Children
If orlistat is prescribed for children, a 6- to 12month trial is recommended, with regular review to assess effectiveness, adverse effects and adherence. In October 2014, this was an off-label use of orlistat. See NICE's information on prescribing medicines. 

# Surgical interventions
Bariatric surgery is a treatment option for people living with obesity if all of the following criteria are fulfilled:
They have a BMI of 40 kg/m2 or more, or between 35 kg/m2 and 40 kg/m2 and other significant disease (for example, type 2 diabetes or high blood pressure) that could be improved if they lost weight.
All appropriate non-surgical measures have been tried but the person has not achieved or maintained adequate, clinically beneficial weight loss.
The person has been receiving or will receive intensive management in a tier 3 service (for more information on tier 3 services, see NHS England's report on joined up clinical pathways for obesity).
The person is generally fit for anaesthesia and surgery.
The person commits to the need for long-term follow-up. See recommendations 1.10.12 and 1.10.13 for additional criteria to use when assessing children, and recommendation 1.10.7 for additional criteria for adults. See also recommendations 1.11.1 to 1.11.3 for additional criteria for people with type 2 diabetes. 
The hospital specialist and/or bariatric surgeon should discuss the following with people living with severe obesity if they are considering surgery to aid weight reduction:
the potential benefits
the longer-term implications of surgery
associated risks
complications
perioperative mortality. The discussion should also include the person's family, as appropriate. 
Choose the surgical intervention jointly with the person, taking into account:
the degree of obesity
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. 
Provide regular, specialist postoperative dietetic monitoring, including:
information on the appropriate diet for the bariatric procedure
monitoring of the person's micronutrient status
information on patient support groups
individualised nutritional supplementation, support and guidance to achieve long-term weight loss and weight maintenance. 
Arrange 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 is now available to conduct national audit for a number of agreed outcomes.) 
The surgeon in the multidisciplinary team should:
have had a relevant supervised training programme
have specialist experience in bariatric surgery
submit data for a national clinical audit scheme (the National Bariatric Surgery Registry is now available to conduct national audit for a number of agreed outcomes). 

## Adults
In addition to the criteria listed in recommendation 1.10.1, bariatric surgery is the option of choice (instead of lifestyle interventions or drug treatment) for adults with a BMI of more than 50 kg/m2 when other interventions have not been effective. 
Orlistat may be used to maintain or reduce weight before surgery for people who have been recommended surgery as a first-line option, if it is considered that the waiting time for surgery is excessive. 
Surgery for obesity should be undertaken only by a multidisciplinary team that can provide:
preoperative assessment, including a risk-benefit analysis that includes preventing complications of obesity, and specialist assessment for eating disorders
information on the different procedures, including potential weight loss and associated risks
regular postoperative assessment, including specialist dietetic and surgical follow up (see recommendation 1.12.1)
management of comorbidities
psychological support before and after surgery
information on, or access to, plastic surgery (such as apronectomy) when appropriate
access to suitable equipment, including scales, theatre tables, Zimmer frames, commodes, hoists, bed frames, pressure-relieving mattresses and seating suitable for people undergoing bariatric surgery, and staff trained to use them. 
Carry out a comprehensive preoperative assessment of any psychological or clinical factors that may affect adherence to postoperative care requirements (such as changes to diet) before performing surgery. 
Revisional surgery (if the original operation has failed) should be undertaken only in specialist centres by surgeons with extensive experience because of the high rate of complications and increased mortality. 

## Children
Surgical intervention is not generally recommended in children or young people. 
Bariatric surgery may be considered for young people only in exceptional circumstances, and if they have achieved or nearly achieved physiological maturity. 
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, and specialist assessment for eating disorders
information on the different procedures, including potential weight loss and associated risks
regular postoperative assessment, including specialist dietetic and surgical follow up
management of comorbidities
psychological support before and after surgery
information on or access to plastic surgery (such as apronectomy) when appropriate
access to suitable equipment, including scales, theatre tables, Zimmer frames, commodes, hoists, bed frames, pressure-relieving mattresses and seating suitable for children and young people undergoing bariatric surgery, and staff trained to use them. 
Coordinate surgical care and followup around the child or young person and their family's needs. Comply with the approaches outlined in the Department of Heath's a call to action on obesity in England. 
Ensure all young people have had a comprehensive psychological, educational, family and social assessment before undergoing bariatric surgery. 
Perform a full medical evaluation, including genetic screening or assessment before surgery to exclude rare, treatable causes of obesity. 

# Bariatric surgery for people with recent-onset type 2 diabetes
For the recommendations in this section, the committee considered that recent-onset type 2 diabetes would include those people whose diagnosis has been made within a 10-year time frame.
Offer an expedited assessment for bariatric surgery to people with a BMI of 35 or over who have recent-onset type 2 diabetes as long as they are also receiving or will receive assessment in a tier 3 service (or equivalent). 
Consider an assessment for bariatric surgery for people with a BMI of 30 to 34.9 who have recent-onset type 2 diabetes as long as they are also receiving or will receive assessment in a tier 3 service (or equivalent). 
Consider an assessment for bariatric surgery for people of Asian family background who have recent-onset type 2 diabetes at a lower BMI than other populations (see recommendation 1.2.8) as long as they are also receiving or will receive assessment in a tier 3 service (or equivalent). 

# Follow-up care
Offer people who have had bariatric surgery a follow-up care package for a minimum of 2 years within the bariatric service. This should include:
monitoring nutritional intake (including protein and vitamins) and mineral deficiencies
monitoring for comorbidities
medication review
dietary and nutritional assessment, advice and support
physical activity advice and support
psychological support tailored to the individual
information about professionally led or peer-support groups. 
After discharge from bariatric surgery service follow-up, ensure that all people are offered at least annual monitoring of nutritional status and appropriate supplementation according to need following bariatric surgery, as part of a shared care model of chronic disease management. # Recommendations for research
The guideline committee has made the following recommendations for research.

# New recommendations for research

## Measurements for assessing health risks in adults
What are the most accurate and suitable measurements and boundary values to assess the health risks associated with overweight, obesity and central adiposity in adults of different ethnicities, particularly those from Black, Asian and minority ethnic family backgrounds? 
For a short explanation of why the committee made the recommendation for research, see the rationale section on classifying overweight, obesity and central adiposity in adults .
Full details of the evidence and the committee's discussion are in evidence review A: accuracy of anthropometric measures in assessing health risks associated with overweight and obesity in adults.
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## Measurements for assessing health risks in children and young people
What are the most accurate and suitable measurements and boundary values to assess the health risk associated with overweight, obesity and central adiposity in children and young people of different ethnicities, particularly those from Black, Asian and minority ethnic family backgrounds? 
For a short explanation of why the committee made the recommendation for research, see the rationale section on measures of overweight, obesity and central adiposity in children and young people .
Full details of the evidence and the committee's discussion are in evidence review B: accuracy of anthropometric measures in assessing health risks associated with overweight and obesity in children and young people.
Loading. Please wait.

# Other recommendations for research
See the update information section for more details.

## Follow-up care after bariatric surgery
Do post-operative lifestyle intervention programmes (exercise, behavioural or dietary) improve weight loss and weight-loss maintenance following bariatric surgery? 

## Long-term outcomes of bariatric surgery on people with type 2 diabetes
What is the long-term effect of bariatric surgery on diabetes-related complications and quality of life in people with type 2 diabetes compared with optimal medical treatment? 

## Bariatric surgery in children and young people
What are the long-term outcomes of bariatric surgery in children and young people living with obesity? 

## Obesity management for people with a condition associated with an increased risk of obesity
What is the best way to deliver obesity management interventions to people with particular conditions associated with increased risk of obesity (such as people with a physical disability that limits mobility, a learning disability or enduring mental health difficulties)? 

## Long-term effect of very-low-calorie diets on people with a BMI of 40 kg/m2 or more
What are the long-term effects of using very-low-calorie diets (VLCDs) versus low-calorie diets (LCDs) on weight and quality of life in patients with a body mass index (BMI) of 40 kg/m2 or more, including the impact on weight cycling? 

## Comparative risks for different generations of immigrants
Is the risk of ill health the same for first-, second- and third-generation immigrants from black, Asian and other minority ethnic groups at the same BMI and waist-to-height ratio thresholds? 

## Single cut-off points
What are the risks and benefits of developing single-figure cut-off points on BMI and waist-to-height ratio for black, Asian and other minority ethnic groups to help prevent diabetes and other conditions? 

## Awareness of risk among black, Asian and other minority ethnic groups
Are black, Asian and other minority ethnic groups aware that they are at the same risk of type 2 diabetes and mortality at a lower BMI, compared with the white population? 

## Practitioners and providers' awareness of risk in black, Asian and other minority ethnic groups
Are clinicians, practitioners and weight management service providers aware that black, Asian and other minority ethnic groups are at the same risk of type 2 diabetes and mortality at a lower BMI compared with the white population. If so, do they intervene at lower BMI and waist-to-height ratio thresholds? 

## Lifestyle interventions for black, Asian and other minority ethnic groups
How effective and cost effective are lifestyle interventions for people from black, Asian and other minority ethnic groups at different BMI and waist-to-height ratio thresholds, compared with the general population? # Rationale and impact
These sections briefly explain why the committee made the 2022 recommendations and how they might affect practice.

# Identifying and assessing overweight, obesity and central adiposity in adults
Recommendations 1.2.2 to 1.2.5 and 1.2.7 to 1.2.16

## Why the committee made the recommendations
Based on their expertise, the committee agreed that a clear benefit of measuring the waist-to-height ratio is that people can easily do it themselves, interpret their results, and seek advice if they are at increased health risk.
Self-measurement may reduce the sense of discomfort or stigma some people may feel from a healthcare professional doing the waist circumference measurement. People can also use resources to help them measure their waist accurately, such as the NHS BMI healthy weight calculator, and videos by Diabetes UK and the British Heart Foundation.
When a person seeks advice because self-measurement indicates an increased health risk, they may need further assessment (such as for cardiometabolic risk factors) and their waist-to-height ratio may be measured again. The committee were aware that there may be situations when a professional taking a measurement may have a negative effect or be inappropriate, because of the stigma attached to it. And some people may not want to be measured because of their religious and cultural beliefs. The committee agreed on the importance of being sensitive to people's needs and recognising when it is not appropriate to measure. The committee noted that sensitivity and stigma will be addressed in a forthcoming update of the guideline.
The committee looked at evidence from studies on the accuracy of different measures for predicting or identifying health conditions associated with overweight and obesity, including type 2 diabetes and cardiovascular disease. The quality of the evidence was mixed. Most studies included information on how accurate the measures were at predicting or diagnosing the health risks associated with overweight and obesity, in people of different ethnicities. Overall, the studies showed that body mass index (BMI), waist circumference, waist-to-hip ratio and waist-to-height ratio could all accurately predict or identify weight-related conditions. The committee noted that BMI is still a useful practical measure, particularly for defining overweight and obesity. But they emphasised that it needs to be interpreted with caution because it is not a direct measure of central adiposity. The committee highlighted that waist-to-height ratio offers a truer estimate of central adiposity by using waist circumference in the calculation. Based on evidence and their experience, they agreed that using waist-to-height ratio as well as BMI would help give a practical estimate of central adiposity in adults with BMI under 35 kg/m2. This would in turn help professionals assess and predict health risks. But because people with a BMI over 35 kg/m2 are always likely to have a high waist-to-height ratio, the committee recognised that it may not be a useful addition for predicting health risks in this group.
BMI is the main measure for defining overweight and obesity, and the committee did not alter the BMI categories for the general population. But, based on their expertise, they agreed it was important to estimate central adiposity when assessing future health risks, including for people whose BMI is in the healthy weight category. The committee also highlighted the need for caution when interpreting BMI in adults with high muscle mass because it may be less accurate in this group.
Age-related changes in the body are not well captured by BMI. The committee agreed that BMI should therefore be interpreted with caution in people aged 65 and over, because their functional capacity may be reduced due to conditions such as age-related spinal disorders or sarcopenia. They also recognised that slightly higher BMI in older people can have a protective effect (for example, reduced risk of all-cause mortality) because they are less likely to be experiencing undernutrition. So, it is important for professionals to evaluate the balance of these risks when interpreting BMI.
The committee also highlighted that people from Black, Asian and minority ethnic family backgrounds are prone to central adiposity and have an increased cardiometabolic health risk at lower BMI thresholds. For example, studies in people of South Asian and Chinese family backgrounds showed an increased risk at a BMI of 21 kg/m2 to 26 kg/m2, whereas people from white family backgrounds showed increased risks at 25 kg/m2 to 29 kg/m2.
There was also some evidence for using lower BMI thresholds for people from Middle Eastern (Arab and Iranian), Black African, Black Caribbean and other Asian (Japanese, Korean and Thai) family backgrounds. For these groups, studies identified an increase in risk at BMI values that ranged from 21 kg/m2 to 30 kg/m2 but most were below 25 kg/m2. The committee noted that these lower thresholds are in line with international guidance and are already used in practice to refer people from these family backgrounds to weight management services.
Although NICE found no evidence on the thresholds for obesity classes 2 and 3 in people of these family backgrounds, the committee consensus was that it is generally good practice to reduce the thresholds used for the general population by about 2.5 kg/m2. This would mean that the threshold for obesity class 2 would be lowered to roughly 32.5 kg/m2, and for class 3 to 37.5 kg/m2 in these populations. Public Health England guidance on adult weight management and the British Obesity and Metabolic Surgery Society guidance on accessing tier 4 services also endorsed reducing the thresholds.
In line with their recommendations for other populations, the committee used the terms overweight and obesity instead of risk levels to describe thresholds in people with a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background. They agreed that in their experience there was more stigma attached to talking about risk than overweight or obesity. They noted that terms such as 'high risk' could result in anxiety and overinterpretation of risk more than terms such as 'living with obesity'.
The committee also discussed the accuracy of waist-to-height ratio boundary values in predicting and identifying health risks. The evidence showed that the cut-off from individual studies was generally around 0.5 for all ethnicities and sexes, which was in line with the wider evidence. They agreed that waist-to-height ratio could be used to define central adiposity in adults, and that a range of 0.5 to 0.59 corresponds to increased health risks. The committee noted that a waist-to-height ratio of 0.6 or more indicates a further increase in risk.
The committee agreed that a key benefit of using waist-to-height ratio is that the classification is the same for all ethnicities and sexes. It can also be useful in adults with high muscle mass, for whom BMI may be less accurate.
The committee also noted the boundary value of 0.5 could be communicated in a simple and memorable way with the message: 'Keep your waist to less than half your height'.
Although there was a large evidence base, the committee noted a lack of evidence on the accuracy of methods for predicting future risks for people of some ethnicities. Few studies were based in the UK, so the evidence might not reflect how accurate different measures might be when used in a UK context. Therefore, the committee highlighted the need for more research on measurements and boundary values for different ethnicities and made a recommendation for research on measurements for assessing health risks in adults.
The committee agreed that it is important for healthcare professionals to ask for permission before starting any discussions linked to overweight, obesity and central adiposity.
Based on their experience, the committee stressed the importance of sensitive and positive discussions because the stigma associated with obesity can affect people's mental and physical health. This can lead to further weight gain and make them less likely to engage with healthcare professionals. It is especially important to be sensitive when talking to people with conditions such as eating disorders (such as anorexia nervosa, bulimia and binge eating disorder), or disordered eating (such as restrictive dieting, compulsive eating or skipping meals).
The committee noted existing resources and advice that could help conduct sensitive, person-centred conversations. These include Health Education England's healthier weight competency framework, Obesity UK's language matters, and training courses by the Royal College of General Practitioners (RCGBP), World Obesity Federation and European Association for the Study of Obesity (EASO).
The committee did not make specific recommendations on sensitive language and measures to prevent stigma because a forthcoming update of this guideline will address these.
The committee noted it is important for adults to know the long-term health risks and conditions associated with overweight, obesity and central adiposity. These include type 2 diabetes, cardiovascular disease, hypertension, dyslipidaemia, certain cancers, and respiratory, musculoskeletal or other metabolic conditions (such as non-alcoholic fatty liver disease). Knowledge about these may encourage the person to stick to a weight loss strategy. Based on their understanding of practice, the committee stressed the importance of an all-round discussion of the person's individual needs and preferences to reach a shared decision about what level and types of intervention would suit them. This includes taking into account factors such as ethnicity, weight-related comorbidities, socioeconomic status, family medical history and special educational needs and disabilities (SEND). These discussions can also involve giving information about local weight management services and other support services.
Based on their expertise, the committee agreed people with weight-related comorbidities may benefit from a higher level of intervention. They also highlighted groups of people, such as those newly diagnosed with type 2 diabetes and those with BMI over 50, who would benefit more from immediate weight management interventions. Based on their expertise, the committee noted that these groups are often not offered appropriate interventions early enough.

## How the recommendations might affect practice
The committee highlighted that encouraging self-measurement is in line with changes in practice over the past 2 years, particularly the increase in carrying out initial assessments by phone. It has already become standard practice to use self-reported measurements such as weight, blood pressure readings and blood sugar levels for conditions like diabetes.
Using waist-to-height ratio as well as BMI would be likely to have minimal cost impact because tape measures are already routinely available in NHS settings for measuring waist circumference.
The committee noted that community pharmacies have been involved in taking measurements as well as it being done in general practice. Public Health England's Healthier weight competency framework highlights that healthcare professionals involved in identification of overweight and obesity should be able to accurately measure and classify weight status. With the addition of waist-to-height ratio, it is important that training is available so that measurements can be conducted by trained personnel.
Currently, there are no established resources for calculating waist-to-height ratio. But resources such as the NHS BMI healthy weight calculator can be used to explain how to take waist measurements. Additional training programmes may need to be developed to help healthcare professionals understand central adiposity and conduct waist measurement in a sensitive manner and with care, especially in people with specific conditions such as eating disorders. This will lead to additional training costs. There may also be a cost increase associated with the extra staff time needed to teach people how to measure themselves and calculate waist-to-height ratio. But the committee agreed that these additional costs are unlikely to result in a significant resource impact and will be balanced out by the long-term health improvements such as decreased risk of developing diabetes or cardiovascular disease.
Using lower BMI thresholds in people from Black, Asian and minority ethnic family backgrounds will increase the number of people who are eligible for weight management services. However, this could reduce levels of overweight and obesity, and thereby reduce the costs of treating obesity-related conditions for the NHS and wider system, such as social care systems.
There may be challenges in using BMI or waist-to-height ratio in people who have a physical disability, some physical conditions (such as scoliosis) or learning difficulties because people may be unable to get on scales independently or be lifted safely. In such circumstances, reasonable adjustments would be needed for adults, for example using seated or hoist scales, or scales that can used for wheelchairs (including moulded wheelchairs). Measurements may also need to be modified, for example using sitting height or demi-span (the distance between the mid-point of the sternal notch and the finger roots with the arms outstretched laterally) instead of overall height, meaning specialist assessment may be needed. It may also be challenging to take measurements in people who are housebound because it may not be possible to access equipment such as specialist scales during home visits.
Return to recommendations

# Identifying and assessing overweight, obesity and central adiposity in children and young people
Recommendations 1.2.21 and 1.2.22 and 1.2.24 to 1.2.29

## Why the committee made the recommendations
The committee were aware of the need to update advice on sensitivity when taking measurements, remaining mindful and sensitive to children and young people's needs (including cultural and religious beliefs) as well as the needs of their parents and carers, and recognising when it is not appropriate to measure. They did not make any recommendations because this section will be reviewed as part of a forthcoming update of the guideline.
The committee looked at evidence on the accuracy of different measures for predicting or identifying health conditions associated with overweight and obesity, including type 2 diabetes and cardiovascular disease. The quality of the evidence was mixed. Some studies included information on how accurate measures were at predicting or diagnosing the health risks associated with overweight and obesity in children and young people of different ethnicities.
Overall, the committee agreed that the studies showed that BMI, waist circumference and waist-to-height ratio could all be used to accurately predict or identify weight-related conditions when they were adjusted for age and sex. The same was true of waist-to-height ratio when it was not adjusted for age and sex. They discussed that BMI z-score adjusted for sex and age tended to be the most accurate measure for identifying different health conditions, but waist-to-height ratio was often equally accurate and, in some studies, more accurate. (BMI z-score is also known as BMI standard deviations , which indicate how many units a child's BMI is above or below the average BMI value for their age group and sex.)
Based on the evidence and their clinical expertise, the committee agreed that BMI is a useful practical measure for estimating and defining overweight and obesity. However, they noted that BMI should not be interpreted in the same way for children and young people as for adults. Healthcare professionals should use charts that are specific to children and young people and adjusted for age and sex. The committee also noted that waist-to-height ratio is a truer estimate of central adiposity, which is related to health risks.
The committee agreed that special growth charts may be needed when assessing children and young people with cognitive and physical disabilities, including those with learning disabilities. They noted that growth charts for children and young people with Down's syndrome are available from the Centres for Disease Control and the Royal College of Paediatrics and Child Health.
The committee agreed that the evidence for using waist-to-height ratio as a practical estimate for central adiposity to assess and predict health risk in children and young people was not as good as the evidence for adults. They agreed that it could still be useful as an indication of future health risks. But they stated that more research was needed on the accuracy of different measures and made a recommendation for research on measurements for assessing health risks in children and young people.
The committee looked at evidence for different boundary values for BMI and BMI z-scores but these focused on identifying current health conditions rather than defining the degree of overweight and obesity. Based on their expertise, they provided clinical definitions of overweight and obesity using BMI centiles and BMI SDs. These values correspond with those in the Royal College of Paediatrics (RCPCH) and Child Health UK-World Health Organization (WHO) growth charts. The committee agreed that it was important to use clinical judgement when interpreting BMI below the 91st centile, especially because children and young people in the healthy weight category may still have central adiposity.
The committee also noted that there are resources that can help professionals understand how to measure, plot and assess BMI in children and young people. These include educational resources from the RCPCH and the National Child Measurement Programme Operational Guidance, which both give information on how the clinical definitions of BMI link to BMI centiles and SDs.
There was a lack of evidence identified on BMI boundary values for children and young people from different ethnicities. The committee agreed this was an important area for research to investigate whether there are variations in thresholds, as there are in adults, and made a recommendation for research on measurements for assessing health risks in children and young people. The committee noted that although they could not provide different thresholds for BMI, waist-to-height ratio could be used as an indicator of central adiposity regardless of ethnicity and sex.
Studies also suggested that the optimal waist-to-height ratio cut-offs for children and young people ranged from 0.42 to 0.57, with most studies averaging around 0.5. Based on the evidence and their clinical knowledge, the committee agreed the waist-to-height ratio boundary value of 0.5 should be the same for children and young people as for adults.
The committee agreed that it is important to ask for permission from children, young people, and their parents or carers (if appropriate), before starting any discussions linked to overweight, obesity or central adiposity. They agreed that professional judgement is needed to ensure discussions are age appropriate and decide whether the child or young person should be involved. They also noted that it was standard practice for healthcare professionals to use Gillick competency to determine the capacity of a child or young person under 16 to consent.
Based on their expertise, the committee stressed the importance of sensitive and positive discussions because the stigma associated with obesity can affect a child or young person's mental and physical health. It is especially important to be sensitive when talking to children and young people with conditions such as eating disorders (such as anorexia nervosa, bulimia and binge eating disorder), or disordered eating (such as restrictive dieting, compulsive eating or skipping meals).
The committee noted existing resources and advice that could help conduct conversations with children and young people in a sensitive and positive way. These include Health Education England's healthier weight competency framework, Public Health England's let's talk about weight (which highlights a focus on weight maintenance and growing into a healthier weight, rather than weight loss) and Obesity UK's language matters guidance. There are also training courses by the Royal College of General Practitioners (RCGBP), World Obesity Federation and European Association for the Study of Obesity (EASO).
The committee did not make specific recommendations on sensitive language and measures to prevent stigma because a forthcoming update of this guideline will address these.
Based on their clinical expertise, the committee agreed that tailored interventions were useful for children who are living with overweight or obesity or have increased health risk based on waist-to-height ratio. They agreed that weight-related comorbidities, ethnicity, socioeconomic status, social complexity (for example, looked-after children and young people), family medical history, mental and emotional health and wellbeing, developmental age, and special educational needs and disabilities (SEND) need to be taken into account when tailoring interventions.
The committee were particularly aware that children and young people with weight-related comorbidities, such as type 2 diabetes, may benefit from a higher level of intervention regardless of their waist-to-height ratio. The committee stressed the importance of working with the child or young person, and their families and carers (if appropriate), to make an informed decision about the treatment or care option that is best for them. As highlighted in resources such as the step-by-step guide produced by Public Health England on conversations about weight, healthcare professionals can also give information about local weight management services and other support services during these discussions.

## How the recommendations might affect practice
Waist-to-height ratio is not routinely measured in practice, so there may be additional costs for the extra staff time involved. But the cost impact should be small because waist measurements are already widely used in primary care so it would not need much extra time to calculate the ratio.
The committee noted that health visitors and school nurses, as well as general practice, are involved in taking measurements. The healthier weight competency framework does highlight that healthcare professionals involved in identification of overweight and obesity should be able to accurately measure and classify weight status in children and young people. With the addition of waist-to-height ratio, it is important that training is available so that measurements can be conducted by trained personnel.
There are no established resources for measuring waist-to-height ratio, but healthcare professionals can use the NHS BMI healthy weight calculator, and videos by organisations such as Diabetes UK and the British Heart Foundation. These are for adults but can also be useful for older children and young people, families and carers.
There are a few training programmes specifically for managing overweight and obesity in children and young people, such as the ones by the World Obesity Federation, European Childhood Obesity Group, the Department of Health and Social Care's obesity team and Health Education England. Some of these need to be updated to include measuring waist circumference and interpreting waist-to-height ratio, which might lead to additional training costs. Healthcare professionals may need extra time to teach older children and young people, and their families and carers, how to measure the waist accurately and calculate waist-to-height ratio. However, the committee agreed that additional costs of training and staff time are unlikely to result in a significant resource impact and are justified by the long-term health benefits associated with a reduction in obesity-related conditions.
There may be challenges in using BMI or waist-to-height ratio in children and young people with physical disabilities, some physical conditions (such as scoliosis) or learning difficulties. Reasonable adjustments would also be needed for children and young people using wheelchairs (including moulded wheelchairs) such as using seated or hoist scales, or scales that are suitable for wheelchairs. And although there is published guidance on supporting people with learning disabilities in obesity and weight management, there are no validated proxy measurements for height in children and young people (for example, using their sitting height or demi-span to estimate their height). This makes taking measurements difficult in children and young people with physical disabilities or learning difficulties.
Return to recommendations# Context
The 2019 Health Survey for England estimated the prevalence of obesity in adults in England to be 28%, with overweight affecting a further 36%. It estimated the prevalence of obesity in children aged 2 to 15 to be 20% in boys and 13% in girls, with overweight affecting a further 12% of boys and 15% of girls. Government estimates indicate that the current costs of obesity in the UK are 6.1 billion to the NHS and 27 billion to wider society.
Currently, people who would benefit from weight management interventions are identified opportunistically. The lack of active case finding may mean that conditions such as type 2 diabetes are likely to be under-diagnosed in people of Black, Asian and other minority ethnic backgrounds whose risk is increased at a lower body mass index (BMI) and waist circumference.
New evidence identified since this guideline was first published may help to refine weight management programmes that address diet, physical activity and behaviour change, and inform implementation of interventions in specific settings.
This guideline update covers identifying and assessing overweight, obesity and central adiposity in children aged 2 years and older, young people and adults. It updates NICE's guideline on obesity: identification, assessment and management (NICE guideline CG189) and replaces NICE's guideline on BMI: preventing ill health and premature death in Black, Asian and other minority ethnic groups (NICE guideline PH46).
Forthcoming updates will cover preventing and managing these conditions. They will produce a single guideline that will partially replace NICE's guideline on weight management before, during and after pregnancy (NICE guideline PH27; only the recommendations that apply before and after pregnancy) and will fully update and replace this guideline and NICE's guidelines on:
preventing excess weight gain (NICE guideline NG7)
weight management: lifestyle services for overweight or obese adults (NICE guideline PH53)
weight management: lifestyle services for overweight or obese children and young people (NICE guideline PH47)
-besity: working with local communities (NICE guideline PH42)
-besity prevention (NICE guideline CG43).