GLP-1 users may be making a major weight-loss mistake, new study suggests

Key Points:

• New research presented at ENDO 2026 found that adults with obesity who lost weight using GLP-1 medications like Ozempic or Wegovy significantly reduced their physical activity, with average daily steps dropping from 5,047 to 4,487 and moderate-to-vigorous activity decreasing from 28 to 22 minutes.
• Study lead Dr. Sajana Maharjan emphasized that exercise remains essential for preserving muscle mass and long-term health in patients using GLP-1 drugs, which reduce both fat and lean muscle mass.
• Experts note that weight loss from GLP-1 medications does not automatically increase motivation or ability to exercise, as side effects and a calorie deficit can reduce energy and physical activity; therefore, targeted interventions to encourage exercise alongside medication are critical.
• Some clinicians, like Dr. Amanda Kahn, challenge the study’s findings, arguing that when GLP-1 therapies are prescribed with comprehensive support including nutrition and resistance training, patients often become more active and healthier rather than less.
• The study was retrospective and observational, limiting causal conclusions, and the mostly middle-aged female sample may not represent all populations; factors like prior exercise habits and physician guidance were not measured.