Weight-loss drugs like Ozempic may cut physical activity, new study reveals

New research presented at ENDO 2026 shows that GLP-1 receptor agonists may reduce physical activity in adults with obesity. The study highlights an unexpected side effect of these widely used weight-loss drugs. Experts say the findings could change how patients are advised on exercise alongside medication. The study is the first large-scale analysis to use wearable fitness tracker data for assessing activity levels in GLP-1 users. It found a 10% drop in average daily step counts after starting treatment. Moderate-to-vigorous physical activity also declined in many participants.

Men and those with joint or muscle pain saw the sharpest decreases in movement. Despite significant weight loss, the medication did not encourage more exercise. Drugs like semaglutide, liraglutide, dulaglutide, and tirzepatide affect both fat and muscle mass, which may contribute to the reduced activity.

Dr. Sajana Maharjan stressed the importance of structured exercise programmes for patients on these medications. She called for exercise to be treated as a necessary part of obesity treatment, not an optional extra. The findings urge a rethink in patient counselling for endocrinologists, GPs, and rehabilitation specialists. They also highlight the need for further research into why these drugs lower activity levels. Clinicians may now place greater emphasis on interdisciplinary care to support long-term health outcomes.