Muscle Preservation on a GLP-1: Protein, Creatine, and Training

Why lean mass drops on a GLP-1

Any large calorie deficit triggers the body to break down some muscle for fuel, especially when protein intake is low and the muscle is not being loaded. GLP-1 medications create a deficit faster than most people have ever experienced, and they suppress appetite precisely when protein intake needs to go up.

The result is a common pattern: excellent scale progress, declining strength, and a body composition that looks softer than the weight loss suggests it should.

Your protein target

The practical range for people losing weight is 1.2–1.6 g of protein per kilogram of body weight per day, spread across meals rather than concentrated in one. For a 90 kg person that is roughly 110–145 g daily.

This is where appetite suppression bites hardest. A stomach that empties slowly cannot easily accommodate three large protein-heavy meals, so the practical answer for most people is two moderate meals plus a shake.

• Aim for 25–40 g of protein per eating occasion
• Prioritise protein first on the plate, before carbohydrates and fats
• A whey isolate shake delivers 25–30 g in a volume most people can tolerate even on a bad appetite day
• Spread intake — muscle protein synthesis responds better to repeated doses than to one large one

Creatine: the highest-evidence addition

Creatine monohydrate is one of the most studied supplements in existence, and its benefit is specifically relevant here: it supports strength output and helps retain lean tissue during a deficit. It works whether or not you are in a calorie surplus.

Three to five grams daily is the standard dose. No loading phase is required; saturation just takes a few weeks longer. Take it at a consistent time — timing relative to training does not meaningfully change the result.

• 3–5 g of creatine monohydrate daily, every day, including rest days
• No loading phase needed
• Take with fluid — creatine draws water into muscle, so hydration matters more, not less
• Expect a small scale increase in the first weeks from intramuscular water, not fat

The training minimum

Protein and creatine give the body the raw materials. Resistance training is the signal that tells it to keep the muscle. Without the signal, the materials do less.

Two to three sessions a week covering the major movement patterns is enough to preserve most lean mass during a deficit. You are not trying to build; you are trying to keep.

• Two to three sessions weekly, 30–45 minutes each
• Cover push, pull, squat/hinge, and carry patterns
• Track your working weights — stable or rising strength is the best real-world sign you're keeping muscle
• Walking is excellent for health and transit but does not preserve muscle on its own

Signs you may be losing muscle

• Working weights falling week over week at the same rep count
• Everyday tasks — stairs, carrying groceries — feeling disproportionately harder
• Weight dropping quickly while clothes fit much the same way
• Persistent fatigue that hydration and sleep don't resolve