The before-and-after photos are everywhere now, and I understand why people share them. There’s real relief in visible progress after years of trying. But the number that keeps pulling my attention isn’t the scale reading, it’s what proportion of that lost weight was actually fat versus lean tissue. SURMOUNT-1 included DEXA sub-studies at selected sites, and the body composition findings are more nuanced than the headline 20%+ weight loss figure. The fat mass reduction is substantial, but lean mass loss was also present, roughly 10-12% of total weight lost across the highest-dose groups depending on how you read the analysis. That sits within the range seen in dietary restriction without resistance training, which is the comparison that matters if you’re thinking about this beyond the cosmetic result. The reason I keep returning to this: the longevity argument for GLP-1s rests partly on reducing visceral adiposity and metabolic stress. Both effects are real and I don’t want to dismiss the cardiometabolic signal, which is strong. But if lean mass is also declining at meaningful rates, particularly in people over 50 who are already losing muscle at roughly 1% per year, the net benefit calculation for that group becomes genuinely complicated. Sarcopenia risk doesn’t get discussed much in the before/after threads. The SURMOUNT-4 extension data on maintained weight loss is encouraging, and I’m not suggesting the drugs do more harm than good. But the framing that dominates most discussions strips out the composition piece entirely, and that’s where the longevity question actually lives for anyone tracking this seriously. Has anyone here had a DXA scan before starting and then again a few months in? Would be very interested to hear what the real-world numbers look like outside a trial setting.