A new definition of obesity could help treat millions of people

Rethinking the way we define obesity could help millions of people around the world, says a team of researchers who want to introduce a new category of “preclinical” obesity.

The current definition of obesity, as defined by the World Health Organization, is the presence of excess body fat that poses a health risk. The World Health Organization recommends that healthcare workers assess whether people are obese by calculating their body mass index (BMI), a measure of weight for height. A BMI between 18.5 and 24.9 is considered healthy, while a lower or higher number indicates that a person is underweight or overweight. A BMI above 30 indicates that a person is obese.

It is true that high levels of body fat can lead to its infiltration into organs such as the liver and pancreas. Impairing its function. It can also lead to increased inflammation, which increases the risk of diseases such as cancer, liver disease and heart problems.

But BMI poorly reflects a person’s body fat levels. “With regard to BMI, we don’t know whether this ‘excess’ weight is due to excess body fat, muscle mass, or strong bone mass,” he says. Francesco Rubino At King’s College London, who led the review into obesity.

Even when properly evaluated, through waist measurement or, in rare cases, X-rays, body fat levels do not fully determine a person’s health. “No two people respond the same way to excess body fat. This is influenced by a person’s race and ethnicity, age, and the foods they eat, and genetics play a huge role. Steven Hemsfield At Louisiana State University.

That’s why Rubino and his colleagues want to bring more nuance into the definition of obesity, dividing cases into preclinical and clinical. Both forms can be described by the presence of excess body fat, but only the clinical form involves symptoms caused by excess fat, such as breathing difficulties, heart problems, or difficulty doing daily activities. Meanwhile, preclinical obesity increases the risk of eventually developing such obesity-related symptoms, Rubino says.

This would be similar to how people have prediabetes, where their blood sugar levels are higher than normal, but not high enough to be diagnosed with type 2 diabetes, Rubino says.

Under the proposed changes, healthcare staff will directly measure people’s body fat levels using a waist width or X-ray as well as calculate their BMI, although a person with a BMI above 40 is always assumed to have excess fat. They then use blood tests to evaluate the health of the organs and ask people if they are experiencing symptoms. Blood tests are routinely performed by many doctors anyway, but direct body fat measurements will somewhat add to their workload, Hemsfield says.

If the new definitions are widely adopted by doctors, they could mean counseling and treatment for people who are better suited to their bodies, Rubino says. In general, those with preclinical obesity may only need to monitor their health and adopt lifestyle changes, while those with the clinical form are more likely to need treatment with medication or surgery, Rubino says.

“This will allow us to categorize people into appropriate care more appropriately,” he says. Adrian Brown At University College London.

Laura Gray At the University of Sheffield in the UK, the proposed changes are also welcomed. “It’s sorely needed. These guidelines define for clinical practice what current research says,” she says. “Not everyone who is obese by BMI is unwell, and not everyone with a lower BMI is healthy. “

The updated definitions, which have already been approved by 76 health organizations around the world, could help reduce the stigma surrounding the condition. “The hope is that defining obesity in a more precise way shows that it is a disease in and of itself. It’s not just a result of behavioral things, there are a lot of environmental, psychological and genetic risk factors,” says Gray.