Longevity & AgingGLP-1 Drugs Melt Fat While Largely Sparing Muscle and Metabolic Rate, Review Finds
This narrative review examines how GLP-1 receptor agonists, mainly semaglutide and liraglutide, change body composition beyond the number on the scale. Drawing on clinical trials and meta-analyses, the authors report marked fat loss that preferentially targets visceral fat, the metabolically harmful fat around organs. Lean body mass falls in absolute terms, but the decline is modest and proportionally in line with weight lost, and relative lean mass is often preserved or improved. Resting energy expenditure appears largely maintained, with some reports of increases during long-term therapy. The authors conclude that GLP-1 drugs do not accelerate sarcopenia in people with or without diabetes. Animal data hint at muscle-protective effects. However, stopping treatment typically leads to weight regain, mostly as fat, so continued therapy or lifestyle support appears important. The findings are relevant to obesity, sarcopenic obesity, and wider metabolic disease care.
