How do I keep / protect muscle while losing weight on a GLP-1?

Protecting muscle on a GLP-1 comes down to three things, in priority order, and the good news is they're all within your control.

First, protein. Appetite suppression is the whole point of these drugs, which makes it dangerously easy to under-eat protein specifically. Aim for roughly 1.6 g per kg of your goal body weight, and treat it as the one macro you don't skip, even on low-appetite days.

Second, resistance training two to three times a week. This is the signal that tells your body to hold onto muscle while it's in a deficit. It doesn't need to be elaborate — basic compound lifts or even bands at home work. Without it, the body happily sheds muscle along with fat.

Third, don't lose too fast. Aim for around 1% of body weight per week or less; faster loss tilts the ratio toward muscle. The drug creates the deficit automatically, so your job is purely to aim that deficit at fat with protein and lifting — and then to verify it's working by tracking lean body mass, not just the scale. That's exactly what the GLP-1 Progress Tracker on Calqulate.net is built to do.