Weight Loss Drugs May Be Making Patients Lose More Than Just Fat

Researchers at the University of North Carolina (UNC) School of Medicine have found that popular weight loss and diabetes medications are causing patients to lose more muscle than expected.

The study, published in the Annals of Internal Medicine, focused on incretin-based medications including semaglutide and tirzepatide, which are widely prescribed for obesity and type 2 diabetes. Led by Professor John A. Batsis, an obesity and nutrition specialist, the research found that the proportion of muscle lost during weight loss on these drugs was consistently higher than researchers had anticipated.

Although some muscle loss is considered normal when a person loses weight, the scale of the loss observed in this study raised concern among the research team. Professor Batsis said the findings suggest that muscle loss in relation to total weight reduction deserves much closer attention from both clinicians and researchers.

The team is now urging doctors to monitor the muscle health of patients who are undergoing intentional weight loss with these medications. They are also calling for muscle evaluations to be included as standard measurements in future clinical trials.

One particularly pressing concern is the lack of research involving older patients. The study found that very few existing trials included participants over 60, and none focused specifically on adults aged 65 or over. This is a notable gap, as significant muscle loss in older people can increase the risk of falls and reduce quality of life.

Professor Batsis and his colleagues are calling for new trials designed specifically to assess how these medications affect older adults, with a focus on mobility and overall wellbeing.