Guide
Resistance training, protein intake, and the case for monitoring lean mass.
Body-composition data from GLP-1 trials show that 25-40% of total weight lost can be lean mass if no countermeasures are in place. That is not unique to GLP-1s; it is true of any rapid weight loss. But the magnitude of weight loss these medications produce makes muscle preservation a serious priority.
Lean mass drives resting metabolic rate, glucose disposal, insulin sensitivity, fall risk in older adults, and physical function. Patients who lose substantial muscle during weight loss often regain weight as fat after stopping medication, ending up with worse body composition than they started with. The goal is to lose primarily fat while preserving or even building muscle.
0.7-1.0 g of protein per pound of goal body weight per day. This is the single highest-leverage intervention. Patients who hit this target consistently lose 70-80% fat. Patients who eat 0.4 g/lb or less commonly lose 50-60% fat and 40-50% muscle. Spread protein evenly across 3-4 meals.
Two to four sessions per week of progressive resistance training. This does not require a gym. Bodyweight progressions, resistance bands, and adjustable dumbbells are sufficient. The principle is progressive overload: each session, do slightly more reps, slightly more weight, or slightly better technique than the last. A simple full-body program covering squats, hinges, pushes, pulls, and a core movement, performed 2-3x weekly, captures most of the benefit.
Aggressive calorie restriction on top of GLP-1-induced appetite suppression is the fastest path to muscle loss. Many patients undereat by 700-1,000 calories below maintenance and wonder why they feel fatigued, weak, and look softer even as the scale drops. A reasonable deficit is 500-750 calories below maintenance.
Cardio improves cardiovascular health and burns calories but does not preserve muscle the way resistance training does. Walk 7,000-10,000 steps daily for general health, but do not substitute walking for lifting. The body composition data is unambiguous on this point.
5 g of creatine monohydrate daily improves resistance training performance and may reduce muscle loss during caloric restriction. It is the most-studied supplement in sports nutrition with a strong safety record. Hydrate well; some patients note a slight increase in scale weight (water in muscle) which is benign.
DEXA scans every 4-6 months are the gold standard. Bioelectrical impedance scales (Withings, Tanita, Renpho) are less accurate but track trends reasonably well if you measure under consistent conditions. Tape measurements (waist, hips, arms, thighs) plus monthly photos catch changes the scale will not.
Trial data suggests 25-40% of total weight lost. With proper protein intake and resistance training, this drops to 10-20% and can be lower.
Yes, especially if you are new to lifting or returning after time off. This is called recomposition and is most achievable in the first 6-12 months of training.
Diminishing returns past 1 g/lb of goal weight. Some athletes go to 1.2 g/lb during aggressive cuts. Above that, no demonstrated benefit.
Creatine monohydrate is the most-studied supplement in sports nutrition with a strong safety record. 5 g/day is the standard dose.
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Editorial note. This guide is for educational purposes only and does not constitute medical advice. Always consult a licensed clinician about your specific situation.