GLP-1 Muscle-Preservation Calculator
When you lose weight on a GLP-1, some of what comes off is muscle, not just fat. Enter your weight and how much you plan to lose, and this free tool estimates the lean mass at stake — and the two levers that help you keep it.
Your estimate
Lean mass at stake
10–16 lb
of what you lose could be lean mass, which includes muscle — unless you protect it
Protein to aim for
145 g/day
a middle target (109–181 g range)
Resistance training
2–3 / week
short sessions that work your major muscle groups
These are rough estimates for planning, not a prediction or medical advice — how much lean mass anyone loses varies a lot, and your protein needs are personal. The takeaway is the pattern, not the exact number: enough protein plus resistance training are the two levers that help you hold onto the muscle. Talk to your healthcare provider before starting an exercise program.
What the numbers mean
Lean mass at stake is a rough range, because a meaningful share of the weight you lose can be lean mass — which includes muscle — rather than fat. It’s an estimate for planning, not a prediction: how much you actually lose depends on how fast you lose, your protein, and your training.
Protein and resistance training are the two levers that move that number. Enough protein gives your body the material to hold onto muscle; resistance training is the signal that tells it to. Neither works nearly as well without the other.
The estimate is the easy part — doing the training safely is where it counts. Mira is the AI strength coach built for exactly this: it watches your form through your phone and builds short sessions around your body, so the muscle this calculator says is at stake actually stays on.
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