On a GLP-1? Keep Your Muscle.
The shot handles the weight. We handle what’s left. Up to ~39% of GLP-1 weight loss can be muscle — here’s your protein number, the lifts that matter, and a daily plan to protect it.
Free tool: find your daily protein number
The number that should change how you approach this
GLP-1 medications work at reducing weight. The problem is what comes off. In the semaglutide STEP-1 body-composition substudy, about 39% of the total weight lost was lean mass — muscle — a higher share than typical dieting. Muscle is far harder to rebuild than to keep. Lose it now and you end up lighter but weaker, with a slower metabolism and a higher chance of regaining fat later.
The good news — you can cut that loss by more than half
In a New England Journal of Medicine trial, adding supervised strength work dropped the muscle share of weight loss from about a third to roughly 16% — less than half — while preserving grip strength and the ability to rise from a chair. Add adequate protein and the effect compounds. (Lundgren et al., NEJM, 2021; Pasiakos et al., 2013.)
Your protein target — lean high
Clinical consensus for preserving muscle on a GLP-1 starts at 1.2 g per kg of body weight. Because you’re actively protecting muscle, lean to the higher end the evidence supports: 1.6–2.0 g/kg per day, with at least 30 g per meal so your body can use it.
| Your body weight | Daily protein target (1.6–2.0 g/kg) |
|---|---|
| 150 lb (68 kg) | ~109–136 g |
| 180 lb (82 kg) | ~131–163 g |
| 200 lb (91 kg) | ~145–182 g |
| 220 lb (100 kg) | ~160–200 g |
Protein needs are individual; anyone with kidney concerns should confirm their target with their physician.
The lifts that protect muscle — 2 to 3× a week
- Squat pattern (sit-to-stand, goblet squat) — legs and glutes, your biggest muscle
- Hinge pattern (hip hinge, deadlift variation) — the whole back of your body
- Push (press) and Pull (row) — upper body
- Carry (loaded walk) — full-body and grip strength
Compound lifts over isolation. Add load over time. 2–3×/week, every week.
Your daily protein game plan (hit 30g+ per meal)
The target only works if it’s spread across the day. A simple template that lands ~120–150g:
| Meal | Easy 30g+ options |
|---|---|
| Breakfast | 3 eggs + Greek yogurt, or a 2-scoop protein shake |
| Lunch | 6 oz chicken, turkey, or fish, or 1.5 cups cottage cheese |
| Dinner | 6 oz lean beef, salmon, or tofu-and-edamame |
| Snack | 1 scoop whey, a cup of Greek yogurt, or a protein bar (20g+) |
Protein-first rule: on a GLP-1 you fill up fast. Eat the protein on your plate first, so if your appetite quits early, you still got what protects your muscle.
Your week-1 lifting starter (2 sessions, ~30 min each)
Never lifted? Start here. Full-body, twice this week, a day between:
| Movement | Sets × reps | Swap if needed |
|---|---|---|
| Sit-to-stand (chair squat) | 3 × 10 | Bodyweight, no chair |
| Hip hinge to a box | 3 × 8 | Practice the hinge unloaded |
| Wall or incline push-up | 3 × 8 | Counter push-up |
| Seated row (band) | 3 × 12 | Bent-over band row |
| Farmer carry | 3 × 20 steps | Hold one weight, walk |
Add a little load or a rep or two each week. That progression is the muscle-preserving signal.
The muscle-loss warning signs to catch early
You can lose muscle without seeing it on the scale. Catch it by feel:
- Your grip is weakening (jars, bags, handshakes).
- Standing from a low chair is getting harder.
- Your lifts stall or drop even though you’re consistent.
- You feel “skinny-soft” — smaller but not stronger.
The 5-point muscle-preservation checklist
- Hit your protein number every day.
- Resistance train 2–3×/week, compound-focused.
- Progress the load over time.
- Watch the warning signs above.
- Weigh less often, measure strength more. The scale can’t tell fat from muscle. Your lifts and grip can.
What we do — and what we don’t
For clients on a GLP-1, every session with a Fitness Specialist is built around one job: keep lean muscle while the medication works on fat. We build and coach the strength plan and support the nutrition around it. We do not manage your medication, change your dose, or advise on whether to be on a GLP-1 — that is between you and your physician. Our lane is making sure the weight you lose is fat, and the strength you have stays yours.
Common questions
Will you tell me whether to take a GLP-1?
No — that stays with your prescribing physician. We handle the training and nutrition side alongside your medical team.
When should strength work start?
The sooner muscle is challenged during weight loss, the more of it you keep. Sooner is better.
Never lifted before?
Sessions are 1-on-1 and built entirely around your starting point.
This is what we build programs around every day.
Every session at Redefine is one-on-one with a Fitness Specialist who meets you where you are and doesn’t give up — so the weight you lose is fat, and the strength you keep is yours.
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General fitness and nutrition education, not medical advice. We support your plan alongside your medical team; we don’t manage, adjust, or advise on medication, and we don’t diagnose or treat. Confirm protein targets with your physician if you have kidney concerns.