People should take their own waist measurement to identify if they are at risk of potential health problems, NICE has said.
Under updated draft weight management guidelines, which are out for consultation, waist-to-height ratio will be used alongside BMI to find patients at risk for conditions such as type 2 diabetes, hypertension or cardiovascular disease.
Anyone with a BMI under 35 kg/m² will be encouraged to take a waist measurement before seeking advice from a healthcare professional if the measurement ‘indicates an increased health risk’.
The guidelines committee said several studies found the measurement can provide a practical estimate of central adiposity and, when used in addition to BMI, predict weight-related conditions.
NICE also now recommends using lower BMI thresholds for overweight and obesity for people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean families than from other ethnic groups.
BMI should be ‘interpreted with caution’ in those with high muscle mass and people older than 65 but waist measurement can be used in all adults, the guidelines state.
Waist-to-height ratio should also be considered in children aged five and older to assess and predict health risks, they added.
NICE also highlights the importance of healthcare professionals asking permission before any discussions with people that are linked to being overweight, obese or having central adiposity, and to do so in a sensitive and positive manner.
Dr Paul Chrisp, director for centre for guidelines at NICE, said the draft guidance ‘offers people a simple and effective way of measuring their weight so they can understand the factors that could impact on their health and take action to address them.
‘Our committee found that a clear benefit of using the waist-to-height ratio is that people can easily measure it themselves, interpret the results, and seek medical advice if they are at increased health risk.’
Professor Tom Sanders, professor emeritus of nutrition and dietetics at King’s College London, said as a rule of thumb waist measurement was useful for younger and middle-aged adults but there were limitations in older people.
But the calculation would likely ‘classify far more older adults being at risk of diabetes than the current International Diabetes Federation guidelines,’ he added.
Professor Naveed Sattar, professor of metabolic medicine at the University of Glasgow said keeping your waist less than half your height may be an additional useful message for the public.
‘Whether this new message gets taken up is uncertain but it never harms to try new ways to get people to consider their health status.
‘However, in the end, we need better interventions to help people change behaviour and also a less obesogenic environment to improve the health of the nation. There is much to do to tackle the UK’s rising waist girths.’