Identifying and assessing overweight, obesity and central adiposity

1.8 Specific advice for people from ethnic minority backgrounds

1.8.1

Ensure healthcare professionals are aware that people from some ethnic minority backgrounds are prone to central adiposity and so are at an increased risk of chronic weight-related health conditions at a lower BMI. [2025]

1.8.2

Ensure people from these ethnic minority backgrounds (and the families and carers of children and young people from these backgrounds) are aware that they are prone to central adiposity and so are at an increased risk of chronic weight-related health conditions at a lower BMI. Explain these risks in an inclusive and non-stigmatising way. [2025]

See also the section on classifying overweight, obesity and central adiposity in adults.

For a short explanation of why the committee made the 2025 recommendations and how they might affect practice, see the .

Full details of the evidence and the committee's discussion are in evidence review D: identifying overweight and obesity in children, young people and adults.

1.9 Identifying and assessing overweight and obesity in adults

When to take and record measurements in adults

1.9.1

Avoid attributing all symptoms to overweight or obesity (diagnostic overshadowing). If the person is presenting with another health problem or condition (such as hip pain), address this problem or condition first before deciding whether it is appropriate to ask permission to discuss weight. [2025]

1.9.2

Ask for permission each time before discussing overweight, obesity or central adiposity and before taking measurements. See the section on discussion, communication and follow up for steps to think about before discussing overweight, obesity and central adiposity and how to ensure discussions are sensitive and non-judgemental. [2025]

1.9.3

If permission is given, use suitable opportunities to measure and record a person's:

  • height

  • weight

  • waist circumference in people with BMI below 35 kg/m2 so that waist-to-height ratio can be calculated.

    Opportunities could include registration with a GP, routine consultation for long-term conditions, and other routine health checks. [2025]

1.9.4

Ensure that records are kept up to date and shared between providers, if possible and with permission, for people who have self-referred to overweight and obesity management interventions. [2025]

For a short explanation of why the committee made the 2025 recommendations and how they might affect practice, see the .

Full details of the evidence and the committee's discussion are in evidence review D: identifying overweight and obesity in children, young people and adults.

How to take measurements in adults

1.9.5

Encourage adults with a BMI below 35 kg/m² to:

  • measure their own waist-to-height ratio to assess central adiposity

  • 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. [2022]

Box 1 Method for people to measure their own waist and calculate their 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:

  • 38 inches divided by 67 inches = waist-to-height ratio of 0.57 or

  • 96.5 cm divided by 170 cm = waist-to-height ratio of 0.57.

See also the NHS obesity webpage for more information and a video showing how to do this.

Measures of overweight, obesity and central adiposity in adults

1.9.7

Use BMI as a practical measure of overweight and obesity. Interpret it with caution because it is not a direct measure of central adiposity. [2022]

1.9.8

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). [2022]

1.9.9

Do not use bioimpedance as a substitute for BMI as a measure of general adiposity in adults. [2006, amended 2014]

For a short explanation of why the committee made the 2022 recommendations and how they might affect practice, see the .

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.

Classifying overweight, obesity and central adiposity in adults

1.9.10

Classify the degree of overweight or obesity in adults as follows, if they are not in the groups covered by recommendation 1.9.11:

1.9.11

People with a South Asian, Chinese, other Asian, Middle Eastern, Black African or African–Caribbean 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:

  • overweight: BMI 23 kg/m2 to 27.4 kg/m2

  • obesity: 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 1.9.10 by 2.5 kg/m2. [2022]

1.9.12

Interpret BMI with caution in adults with high muscle mass because it may be a less accurate measure of central adiposity in this group. [2022]

1.9.13

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. [2022]

1.9.14

Classify 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. [2022]

1.9.15

When talking to a person about their waist-to-height ratio, explain that they should try and keep their waist to less than half their height (so a waist-to-height ratio of under 0.5). [2022]

For a short explanation of why the committee made the 2022 recommendations and how they might affect practice, see the .

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.

Assessing and managing comorbidities in adults

1.9.16

After the initial assessment of overweight or obesity, identify any comorbidities and other factors that may affect or be affected by the person's weight. Take into account the timing of the assessment, the degree of overweight or obesity, and the results of previous assessments. [2006]

1.9.17

Start managing comorbidities as soon as they are identified; do not wait until the person has lost weight. [2006]

1.10 Identifying and assessing overweight and obesity in children and young people

When to take and record measurements in children and young people

1.10.1

Ensure there are processes to identify children and young people with overweight and obesity in addition to the National Child Measurement Programme and the Healthy Child Programme, particularly for children and young people outside the age groups covered by these programmes, and children not in mainstream state education. [2025]

1.10.2

Avoid attributing all symptoms to overweight or obesity (diagnostic overshadowing). If the child or young person is presenting with another health problem or condition (such as asthma) address this problem or condition first before deciding whether it is appropriate to ask permission to discuss weight. [2025]

1.10.4

If there is a suitable opportunity, ask permission to record an up-to-date measure of a child or young person's height and weight. Potentially suitable opportunities could include routine health checks and non-urgent appointments (such as immunisation appointments). See the section on general principles of care for steps to take before discussing overweight and obesity and on ensuring discussions are sensitive and non-judgemental. [2025]

1.10.5

Consider measuring a child or young person's waist circumference and calculating waist-to-height ratio to predict health risks associated with central adiposity. See recommendation 1.10.10 on using waist-to height ratio in children and young people and defining the degree of central adiposity, and see box 1 for how to measure waist-to-height ratio. [2025]

1.10.6

Ensure that records are kept up to date, if possible, for children and young people and their family and carers who have self-referred to overweight and obesity management interventions. [2025]

For a short explanation of why the committee made the 2025 recommendations and how they might affect practice, see the .

Full details of the evidence and the committee's discussion are in evidence review D: identifying overweight and obesity in children, young people and adults.

Measures of overweight, obesity and central adiposity in children and young people

1.10.7

Use BMI as a practical estimate of overweight and obesity in children and young people, and ensure that charts used are:

1.10.8

Do not use bioimpedance as a substitute for BMI as a measure of general adiposity in children and young people. [2006, amended 2014]

For a short explanation of why the committee made the 2022 recommendation and how it might affect practice, see the .

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.

Classifying overweight, obesity and central adiposity in children and young people

1.10.9

Classify the degree of overweight or obesity in children and young people using the following classifications:

  • overweight: 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. [2022]

1.10.10

Classify 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. [2022]

1.10.11

When talking to a child or young person, and their families and carers, explain that they should try and keep their waist to less than half their height (so a waist-to-height-ratio of under 0.5). [2022]

For a short explanation of why the committee made the 2022 recommendations and how they might affect practice, see the .

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.

Assessing and managing comorbidities in children and young people

1.10.12

After the initial assessment of overweight or obesity, identify any comorbidities and other factors that may affect or be affected by the person's weight. Take into account the timing of the assessment, the degree of overweight or obesity, and the results of previous assessments. [2006]

1.10.13

Consider assessing comorbidities for children with a BMI at or above the 98th centile. [2006]

1.10.14

Start managing comorbidities as soon as they are identified; do not wait until the child or young person has lost weight. [2006]