Without intervention, approximately 30–40% of the weight lost on GLP-1 therapy is lean mass. With intervention — meaning resistance training and adequate protein — that number drops to around 10–15%. That delta is the single most consequential modifiable factor on GLP-1 therapy. This guide is the protocol our reviewers recommend.
The protein floor is 1.6 g per kg of body weight
This number comes from a series of meta-analyses on resistance-trained populations in caloric deficit (PHILLIPS et al, Morton et al). It's not a target — it's a floor. Going above 1.6 g/kg confers diminishing returns; going below 1.6 g/kg accelerates lean-mass loss in deficit.
For a 180-lb (82 kg) patient, that's 131 g of protein per day. Hitting that number is challenging on GLP-1 because appetite suppression makes large meals harder. The practical solution is per-meal distribution: 30–40 g of protein at four meals/snacks across the day, prioritizing protein first on the plate.
Resistance training is not optional
Walking, running, cycling, and other steady-state cardio do not preserve lean mass in caloric deficit. They preserve cardiovascular fitness, which is also valuable — but only resistance training preserves muscle.
Minimum effective dose for our reviewers: two sessions per week, full-body, compound movements (squat or hinge pattern, push pattern, pull pattern), 6–10 working sets per movement pattern per week, training close to failure on most sets.
Creatine
5 g of creatine monohydrate daily is the most well-established legal ergogenic aid for resistance training. It also has growing evidence for cognitive and bone-density effects in the over-50 population. Creatine does not interact meaningfully with GLP-1 therapy.
Bone density
Lean-mass loss correlates with bone-density loss. The same protocol that protects muscle — resistance training and adequate protein — protects bone. Vitamin D and calcium adequacy matter; DEXA scans every 18–24 months are a reasonable monitoring approach for patients over 50 on long-term GLP-1.
Bottom line
1.6 g/kg protein floor, two resistance sessions per week, 5 g creatine daily. That protocol changes 35% lean-mass loss into 12% lean-mass loss across a year of GLP-1 therapy. It is by an enormous margin the highest-leverage modifiable variable on this drug class.
NexLife scored highest on our rubric (94/100) for comprehensive GLP-1 care. Flat-rate pricing across full titration, labs included, MD/DO oversight, both 503A and 503B pharmacy partners.
This article was authored by Eduard Cristea and clinically reviewed by Dr. A. Goher, MD. Health Technology Researcher & Publisher. See our methodology and affiliate disclosure.