The Chronic Disease With No Clinical Classification

Is obesity among the most misunderstood, misclassified, and mistreated diseases?

Over the past 30 years, researchers have not only identified a key hormone (leptin) that helps regulate appetite and body weight, but they’ve also determined the biologic underpinnings (eg, altered central nervous system pathways associated with energy balance) and discovered that obesity is often genetically driven.

Together, these advances, along with the development of the glucagon-like peptide 1 (GLP-1) receptor agonists, suggest that obesity is a chronic disease that might best respond to cohesive medical and lifestyle management.

Why then is obesity still regarded by many as the direct result only of a lack of self-control, poor eating habits, and a sedentary lifestyle? Equally important, what does the future hold for patients with obesity, given that it lacks broad recognition as a chronic disease?

“We’ve been dealing with this for centuries — that obesity’s just about people controlling their behaviors and that treats or prevents the disease,” said Angela Fitch, MD, chief medical officer and co-founder of KnownWell, a healthcare provider focused on primary care and obesity treatment, and past president of the Obesity Medicine Association.

“Data show that only 5%-10% of people are able to lose 20% of their weight; there’s a dichotomy between scientific understanding and the expectations for human biology,” she said.

“We really need to shift the narrative from being one of personal responsibility to what can be done in terms of solutions for these individuals in their health journey,” added Sarah E. Hampl, MD, professor for healthy lifestyles, Center for Children’s Healthy Lifestyles & Nutrition at Children’s Mercy in Kansas City, Missouri, and lead author of the American Academy of Pediatrics’ Clinical Practice Guideline for the Evaluation and Treatment of Children and Adolescents With Obesity.

A Disease Without a Clinical Identity

The contention that obesity can be largely addressed through diet and exercise might have started with Hippocrates as early as 500 BC. Despite recent scientific advances, the clinical community continues to grapple over classifying obesity as a chronic disease, in part because obesity is often characterized as a single entity defined from a single parameter (body mass index [BMI]).

Those in favor of the classification argue that excess fat accumulation/distribution is linked to sustained and serious metabolic and other effects, affects virtually every system in the body, carries the risk for comorbid complications such as diabetes and heart disease, and increases mortality risk.

Those against worry that the lack of a clear, identifiable illness coupled with the focus on BMI (both as a definition and detection) could lead to overdiagnosis in healthy individuals.

A published study, slated for presentation at the European Congress on Obesity in Spain between May 11 and 14, might throw an additional wrench into the BMI-focused naysayers. Findings suggested that people with obesity experience a redistribution of fat and muscle as they age (increased fat accumulation in the trunk area and lower muscle mass in the extremities that doesn’t alter BMI in any meaningful way but may carry significant risk for low-grade chronic inflammation, insulin resistance, and cardiometabolic diseases).

Training Lacking

The lack of clinical clarity is further complicated by the dearth of medical and healthcare professional education.

“Though science has really grown in the past couple of years, awareness has not. There are thousands of physicians who received very little training on the pathophysiology and strong biology of obesity because it was not known at that time,” said Hampl.

Qualitative data have reinforced that general practitioners might be uncomfortable discussing obesity with their patients due to these knowledge gaps, lack of protocols/time/resources, and fear of insulting patients.

Although concerted efforts are being made by professional organizations to promote obesity training and education early in the medical career, the current impact of these initiatives is not much better than in generations past; in a recent study, almost three quarters of a national sample of 4732 first-year medical students exhibited implicit weight bias and 67%, explicit weight bias.

Combating Morality

In addition to clinician-centered education, the solution might be found by centering patients, providing accurate information to dispel misconceptions around obesity, and engaging with real-life, real-time scenarios delivered by real people with obesity.

The goal is to “not only change the cognitive aspects of what the public and clinicians think about obesity but also change how they feel,” explained Rebecca Pearl, PhD, associate professor of clinical and health psychology at the University of Florida’s College of Public Health and Health Professions in Gainesville, Florida.

On the state level, groups like the Chronic Disease Coalition and their patient ambassadors are working with public health officials to elevate patient voices, improve treatment options and insurance coverage, and change public policy, said Executive Director Mary Kay Clunies-Ross, echoing the value of a patient-centered strategy.

However, a patient-centered strategy is only a single step needed to combat current beliefs. 

Stigma and bias go hand-in-hand with the moral framework that is often placed around obesity, adding fuel to the fire of arguments against the chronic disease classification. Karen R. Studer, MD, MBA, MPH, chair of the Department of Preventive Medicine, Loma Linda University School of Medicine, in Loma Linda, California, and The Obesity Society board member, likened it to the way that doctors and the public treated people with addiction issues.

“Several decades ago, we viewed addiction as a moral issue. It wasn’t until science caught up and provided more information about it — how it was a brain disease — that we started treating it as a disease,” she said. “There’s still a long way to go for addiction medicine, but obesity is still thought of as a moral decision,” she said.

Future So Bright?

A recent study examining the global, regional, and national prevalence of overweight/obesity in children and adolescents made the dire prediction that without “immediate action,” 1 in 6 children and adolescents will be living with obesity by the year 2050. Obesity trajectories are also high in the working-age population.

Obesity has been shown to decrease life expectancy and work productivity and carries a substantial financial burden that exceeds $172B annually. Downstream effects include type 2 diabetes, cardiovascular disease, chronic kidney disease, gastrointestinal disorders, nonalcoholic fatty liver disease, cancer, respiratory ailments, and dementia/Alzheimer’s disease. Roughly half of US states still offer no insurance coverage for the GLP-1s in state insurance plans, Medicaid, and small group and individual markets.

“The amount of data that we have on the positive benefits of these GLP-1s like tirzepatide are significant,” said Fitch, citing data demonstrating resolved sleep apnea in 50% of study participants relative to placebo or a 94% relative risk reduction of developing type 2 diabetes in participants with prediabetes or obesity.

“Obesity is a disease like any other, meaning excess adiposity has an adverse effect on your health,” she said.

Hampl, Pearl, and Studer reported no financial disclosures. Clunies-Ross is an independent communication specialist.

Liz Scherer is an independent health and medical journalist.