A team of more than 50 doctors and scientists has concluded that obesity is not always a disease. Their report today in The Lancet Diabetes and Endocrinology, which presses for a more nuanced definition of obesity and new diagnostic standards, also advocates for widespread access to weight loss treatments for those who suffer health complications from carrying extra body weight. The recommendations come as obesity drugs soar in popularity in the United States but remain inaccessible to many people elsewhere in the world.
The new report “legitimiz[es] obesity as a real disease,” but goes beyond body mass index (BMI) as the way to define it, says Katherine Saunders, an obesity physician at Weill Cornell Medicine and co-founder of the company FlyteHealth, which contracts with businesses to expand access to medical obesity treatment for their employees. Saunders, who was not involved in the report, agrees with its authors that scientific research supports using measures beyond BMI, including body composition and assessments of overall health. These measures could better identify who should get treatment, but she notes they may sometimes be difficult to implement.
More than 75 professional groups around the world have endorsed the report, including the American Heart Association, the European Federation of Internal Medicine, and the World Obesity Federation, though it remains to be seen how the recommendations will impact medical practice.
“The question is, what defines disease?” says Francesco Rubino, chair of metabolic and bariatric surgery at King’s College London, who in 2019 proposed the collaboration that led to the report. When it comes to obesity—estimated to affect more than 1 billion people worldwide—that question has long bedeviled the field. BMI, calculated from a person’s height and weight, was conceived of in the 1830s by a Belgian mathematician, and typically a BMI of at least 30 qualifies as obesity. Studies have identified BMI-defined obesity as a driver of health conditions including heart failure, type 2 diabetes, and osteoarthritis. Some organizations, including the American Medical Association, declare all obesity to be a chronic illness, in part to try to reduce stigma around it.
But although Rubino thinks BMI can be a useful tool, he and others say it’s not a medical diagnosis, because it doesn’t clearly track with poor health and suffering. Many people with obesity are metabolically healthy and fit, don’t consider their lives adversely affected by their weight, and may not need any treatment.
In acknowledging this diversity, the new report represents “a departure in many ways” from medical practice today, says Sadaf Farooqi, who studies and cares for people with obesity at the University of Cambridge and served on a steering committee for the report. (It was supported by The Lancet, which forms commissions of academic experts to make recommendations on a topic.) The report’s central argument is that doctors should divvy people with obesity into two categories: those with “clinical obesity” whose weight is causing health problems or affecting day-to-day functioning, and those with “preclinical obesity,” who are otherwise healthy, based on blood tests and other assessments.
This split should have implications for care, the team noted. People with clinical obesity should be able to get medications such as glucagon-like peptide-1 drugs or bariatric surgery, just as people with cancer or heart disease routinely get treatments targeting their disease. That isn’t always the case today, Farooqi says. “The fundamental problem for both physicians and policymakers [is], ‘Do we really need to treat you, should you just pull yourself together and this won’t be a problem?’”
For those with preclinical obesity—who the authors argue aren’t currently ill but may be at higher risk of illness—treatment decisions will be more nuanced. “We are not saying they should not have treatment,” Rubino says, but that “the approach … is different.” It may focus more on health counseling to help reduce the risk of future health problems. Weight loss medication may still be warranted based on other risk factors, such as a concerning family history of obesity-associated illness.
Farooqi and Rubino also hope this recalibration will benefit certain ethnic groups—particularly those of Asian descent, who appear to be at risk of complications from obesity at lower BMIs than white Europeans, the predominant population studied in early research on BMI and health risks.
Another recommendation: Look at where in the body fat resides, not just BMI. Numerous scientific studies have documented that abdominal fat comes with more health risks than fat in the thighs or hips. However, integrating body composition assessments into medical care can be tougher than it sounds, Saunders says, especially for general practitioners who may have less time to spend with their patients. There’s not even agreement on how to measure waist circumference. “For a new classification system to be adopted widely, it would need to be quick, inexpensive, and reliable,” she says.
And figuring out whether and how to treat a person with preclinical obesity—factoring in not just their health, but genetic or other risk factors for disease in the future—may be “really tricky,” she adds.
Farooqi agrees that if doctors adopt the group’s recommendations, there may well be bumps in the road. Technology improvements, such as cheap and easy ways to measure body composition, could make a big difference. “I think in some respects there will be extra work for doctors” under this approach, but the report “gives us a more informed view of how we should assess somebody with obesity,” she argues, and that’s “part of being a good doctor.”
More: https://www.science.org/content/article/obesity-disease-not-always-new-expert-report-says
