Proposed BMI changes could label millions of Brits obese: are you at risk? | Bristol Live

A proposal to modernize the body mass index (BMI) classification could see millions of Britons classified as obese. The BMI system, endorsed by the World Health Organization and used globally, is a tool for health professionals to assess a person’s risk of health problems related to excess body fat.

Currently, a healthy BMI ranges from 18.5 to 24.9, with 25 to 29.9 considered overweight. Scores below 18.5 indicate someone is underweight, while 30+ means obesity – both extremes can pose significant health risks.

However, Italian researchers are proposing a new system where adults over 40 would be classified as obese with a BMI of 27 or higher. This change could label most UK adults as obese, given that the average BMI for this age group is between 27.7 and 27.6, according to NHS data.

This proposed revision could lead to many people being classified as obese without their knowledge.

The authors of the study, presented at the European Congress on Obesity in Venice, argue that the current BMI threshold for obesity may not be appropriate for middle-aged and older adults, The Daily Mail reports.

The researchers explained that after the age of 40, bodies usually have an increased accumulation of fat around the waist. Along with age-related muscle decline, this results in no overall change in their overall weight.

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As a result, despite fat accumulation, the BMI system fails to identify the change, leading people to unknowingly face obesity-related health problems such as heart disease, diabetes and even stroke.

Their findings were supported by a study involving 4,800 Italian men and women between the ages of 40 and 80. Of this group, 38% of men and 41% of women had a BMI of 30 or more, classified as obese according to current guidelines.

However, the study also used high-tech body scans to measure each participant’s body fat. The results showed that 71% of men and 64% of women were rated as obese. This indicated that nearly half of men and women with worrying levels of fat were incorrectly told their BMI was acceptable.

When comparing data from both sets of measurements, they found that adjusting the BMI cutoff to 27 for obesity would capture almost 9 out of 10 of the obese patients detected by the body scan method, Gloucestershire Live reports.

While the new proposal shows some potential for the study population, one criticism of the study was its failure to take into account other factors such as diet, exercise levels and sleep patterns, all of which could influence the likelihood of a people to develop obesity. The conference also emphasized the need for larger-scale studies in different parts of the world to validate the results.

The current BMI system used as a measure of health has long been criticized and calls have been made for its reform. The system, developed by a Belgian mathematician in the 1830s, is based on a calculation method almost two centuries old.

Its major flaw is that it cannot distinguish between fat and muscle mass, relying only on height and weight for calculation. This means that a fit and healthy athlete and a sedentary individual could have the same BMI reading for height and weight, despite one being more muscular.

To calculate your BMI, simply divide your weight in kilograms by your height in meters squared. For example, if you weigh 70kg (about 11 stone) and are 1.73m (about 5ft 8in) tall, you calculate your BMI by: square your height in metres: 1.73 x 1.73 = 2.99 and then dividing the weight by this number: 70 2.99 = 23.41.

Alternatively, you can bypass the calculations and use the NHS BMI calculator instead.