People should ensure their waist measurement is less than half their height to keep health problems at bay, new health guidance proposes.
For the first time, the National Institute for Health and Care Excellence (Nice) is recommending that this measurement is taken into consideration.
Body Mass Index (BMI) can still be useful, they say, but it doesn’t tell the whole picture of a person’s health.
Currently, BMI is used across the NHS and is calculated by dividing an adult’s weight in kilograms by their height in metres squared. A BMI of 18 to 25 is considered a healthy weight, 25 to 30 is overweight, and over 30 is obese.
However, the accuracy of BMI has been debated for some time, particularly given that weight distribution differs among different people. Some who are considered in the “healthy” BMI range may still carry excess fat around their middle, which is known to push up the risk of type 2 diabetes, high blood pressure and heart disease.
The new draft guidance, which is still subject to consultation, is designed to improve accuracy in this regard.
“Waist-to-height ratio is a simple, easy-to-use measure that identifies people who are at increased health risk and would benefit from weight management support to improve their health,” guideline committee member Professor Rachel Batterham, consultant in obesity, diabetes and endocrinology, said.
The new guidance also recommends, in line with international guidance, using “lower BMI thresholds for overweight and obesity for people from south Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean backgrounds”. These groups are more prone to carrying weight around their middle and have higher health risks at lower BMIs.
It also sets out ways to assess childhood obesity and says tailored plans should be considered for children with a high BMI or a waist-to-height ratio above 0.5.
Dr Paul Chrisp of Nice said: “Our updated draft guideline 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.”