Classifying Obesity as a Chronic Disease with W. Timothy Garvey, MD

At the 9th Annual Heart in Diabetes Conference in Philadelphia, PA, W. Timothy Garvey, MD, professor and university professor, Department of Nutrition Sciences, University of Alabama in Birmingham and director of UAB Diabetes Research Center in Birmingham, Alabama, presented the results of the Lancet Commission on Obesity and how these findings will influence the treatment of obesity and its complications moving forward.1

Given the limitations surrounding BMI measurement of obesity, the Lancet Commission aimed to better define obesity as a condition of illness that comes as a direct result of excess adiposity and its effect on the function of tissues and organs. The Commission initially intended to establish specific criteria for diagnosis, thereby facilitating further therapeutic interventions and public health strategies.2

Garvey spoke on several of the contributions he believed were made by the Commission during the process, namely the indication of the various complications of obesity that were used to qualify it as a disease. He noted lymphedema, intracranial pressure, heart failure with preserved ejection fraction, and arterial pressure, among others, as being directly caused by excess adiposity.

“These are complications that are integral to the state of excess adiposity,” Garvey told HCPLive. “And what stronger statement is there that obesity is a disease when you can link it to these types of changes in function and structure of organs that produce symptoms?”

Garvey also spoke on the Commission’s development of a separate category of obesity-related diseases. These were described as diseases whose pathophysiology can overlap with the defined components of obesity. He gave the example of diabetes.

“So, on the obesity side, you have obesity-induced insulin resistance, but patients have to have a decreased insulin secretory capacity in order to produce hyperglycemia and overt diabetes,” Garvey said. “It required a defect in insulin secretion as well as obesity-induced insulin resistance. So that’s an example of an obesity-related disease.”

Notably, one of the Commission’s core decisions proved to be rather controversial in the medical sphere. Garvey expounded on this, explaining the difference drawn between preclinical and clinical obesity as defined by the Lancet Commission. This decision separated the notion of obesity as a risk factor from the actual diseases it can facilitate, establishing it as a disease in its own right.

“Well, preclinical obesity is a state of excess adiposity without complications,” Garvey told HCPLive. “Patients can be active, they feel fine, they can be exercising every day, be productive individuals in society, even though they have excess body weight. It is a state of increased risk.”

Garvey noted that preclinical obesity still requires evaluation, counseling, and eventually some form of intervention, given that it could progress to clinical obesity at any time. However, Garvey did state that not all patients with preclinical obesity need aggressive therapies in the same way as patients with clinical obesity.

“If you have complications or obesity-related diseases, that tells you that the adiposity that’s presented is harming the health of the person, and now therapy is clearly warranted – medication, bariatric surgery, lifestyle intervention, etc,” Garvey said. “We treat the disease with weight loss, not just to lose X amount of pounds, but to achieve sufficient weight loss to prevent or treat the complications that might arise.”

Garvey expressed his interest in the studies that have been undertaken in response to the Commission. He hopes that the field is moving in the direction of preventative measures and treatment, given the new mentality of obesity as a chronic disease.

“I think we’ve seen this complication-centric approach to care is now being integrated into phase 3 development programs for new pharmaceutical medications,” Garvey said. “I think that’s where the field is going, and I think it’s a good thing we’re now treating obesity as a disease. Obesity is now on par with the way we treat other chronic diseases as well.”

Garvey reports the following disclosures: Boehringer-Ingelheim, Novo Nordisk, Eli Lilly, Merck & Co., Inc., Neurovalens, Fractyl Health, Inc., and others.

References

1. Garvey W. The Lancet Commission on Obesity. Presented at the 9th Annual Heart in Diabetes Conference in Philadelphia, PA, June 6-8, 2025.

2. Rubino F, Cummings DE, Eckel RH, et al. Definition and diagnostic criteria of clinical obesity [published correction appears in Lancet Diabetes Endocrinol. 2025 Mar;13(3):e6. doi: 10.1016/S2213-8587(25)00006-3.]. Lancet Diabetes Endocrinol. 2025;13(3):221-262. doi:10.1016/S2213-8587(24)00316-4