Weight loss leads to notable muscle loss, study finds

A new UNC School of Medicine study of incretin-based medications, including newer medications such as semaglutide and tirzepatide that are widely prescribed for type 2 diabetes and obesity, finds they are associated with high rates of muscle loss relative to the amount of weight lost.

John A. Batsis, MD, an expert on obesity and nutrition at the UNC School of Medicine and the UNC Gillings School of Public Health, published his team’s findings in Annals of Internal Medicine.

“While muscle loss is expected during weight loss, we observed that the proportion of weight loss attributable to muscle was consistently higher than anticipated across studies,” said Batsis. “These findings suggest that the magnitude of muscle loss relative to total weight loss warrants closer attention.”

Batsis and his team advise clinicians to carefully monitor a patient’s muscle health when advising intentional weight loss. The findings underscore a need for muscle evaluations and measurements in clinical trials, as well as more trials geared towards older adults taking semaglutide, tirzepatide, and other similar medications.

“Few current studies include participants older than 60 years, and none focused on adults aged 65 years or older,” said Batsis. “Significant muscle loss can lead to a higher fall risk, so additional trials specifically designed to evaluate aging-related outcomes that include mobility and quality of life are urgently needed.”