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Bathroom scales measure weight, not composition. On a GLP‑1, you can lose lean mass faster than fat without protein and resistance training. Here is how to track and prevent it.
A 50 lb weight loss can be 35 lb fat + 15 lb lean mass (typical without resistance training) or 45 lb fat + 5 lb lean mass (with training + protein). The scale shows the same number. Body composition methods distinguish the two.
Enter your numbers to see how much of your projected weight loss is fat versus lean mass — and how much muscle resistance training plus protein could save.
Estimate how much of your weight loss is likely fat versus lean muscle. Inputs stay on your device — nothing is sent anywhere.
Estimates based on published GLP-1 body-composition data (lean mass is typically 20-30% of weight lost without resistance training, falling to ~5-10% with adequate resistance training and protein). Individual results vary. Not medical advice.
A tape measure tells you more than the scale on a GLP-1: it separates fat loss from muscle loss. The U.S. Navy circumference formula gives a quick body-fat estimate from three measurements — track it monthly to see where the weight is actually coming from.
U.S. Navy circumference method — a tape-measure estimate, not a DEXA scan. Useful for tracking change over time (GLP-1 progress is about fat loss, not just scale weight). Measure relaxed, at the navel (waist) and the widest point (hip).
Get a DEXA at baseline. Track protein. Lift twice a week. The patients who do these three things end up with better body composition than the patients who lose more weight without them. The scale alone misleads.
Editorial summary, not medical advice. DEXA scans require physician order in some states. Coordinate body composition tracking with your prescriber.