If you're on Ozempic, Wegovy, Mounjaro, or Zepbound, you already know the medication does the hard part for you. Appetite drops. Portions shrink. The scale moves.
That's exactly where the problem starts.
When your appetite disappears, protein is usually the first thing to go. It's the most filling macronutrient, which sounds great until you realise that "filling" means you stop eating it halfway through the plate. And the weight you lose without enough protein isn't only fat.
The number nobody mentions at the pharmacy
In the body composition substudy of the STEP-1 trial, participants taking semaglutide lost roughly 15% of their body weight over 68 weeks. Fat mass dropped about 19%. But lean mass dropped around 10% from baseline.
Across recent trials, lean tissue has accounted for somewhere between a quarter and 40% of total weight lost.
Two honest caveats, because this stat gets used to scare people:
Most of what you lose is still fat. In STEP-1, fat mass fell roughly twice as fast as lean mass. The goal isn't panic — it's tilting that ratio further in your favour.
"Lean mass" isn't the same as muscle. DXA and bioimpedance scans measure lean soft tissue, which includes water, glycogen, and organ tissue. Losing some of it doesn't automatically mean you got weaker. Researchers reviewing this in 2026 were explicit that lean tissue loss doesn't necessarily translate to impaired strength or physical performance.
So the framing isn't "GLP-1s destroy your muscle." It's simpler: rapid weight loss plus low protein intake is a bad combination, and GLP-1s make low protein intake very easy to fall into by accident.
What the protein target actually is
Current clinical guidance for people losing weight on GLP-1 medications generally lands around 1.2 to 1.6 grams of protein per kilogram of body weight per day, spread evenly across meals rather than dumped into one.
For an 80 kg person, that's roughly 96 to 128 grams daily.
That is a lot of protein when you're not hungry. Which is the entire point of this article: on a GLP-1, hitting protein stops being automatic and becomes something you have to deliberately manage.
Your specific target depends on your starting weight, your goal, your kidney function, and your training. Set it with your prescribing clinician — not with a blog post, and not with an app.
Why guessing fails on a GLP-1
Off medication, appetite is a decent rough guide. You eat until you're satisfied and you land somewhere reasonable.
On medication, that signal is gone. And the gap between what feels like enough and what actually is enough gets wide fast.
Here's the thing that catches people: 55 grams and 95 grams of protein feel identical when you're not hungry. Both days feel fine. Both days you ate when you were supposed to and stopped when you were full. One of them is protecting your muscle and one isn't, and you cannot tell which from the inside.
That's not a willpower problem. It's a measurement problem.
Five tactics that actually work
1. Front-load protein at breakfast. Most GLP-1 users find appetite is worst in the hours right after their dose, and nausea and early fullness make big evening meals hard. Getting 30–40 grams in early means you're not trying to catch up at 9pm on a stomach that's already done.
2. Eat protein first at every meal. Not as a rule about food morality — as a logistics decision. If you can only finish half the plate, make sure the half you finished was the chicken and not the rice.
3. Prioritise protein density over volume. When you can only eat small amounts, grams per bite matter. Greek yogurt, eggs, cottage cheese, fish, poultry, and lean beef give you far more per mouthful than most alternatives. Leucine-rich sources are the most efficient per gram for muscle preservation.
4. Use shakes on low-appetite days without guilt. A protein shake is not a failure to eat properly. On a day when solid food is genuinely unappealing, liquid protein is the difference between hitting 100 grams and hitting 50.
5. Lift something twice a week. Protein alone doesn't preserve muscle — it gives your body the material. Resistance training is the signal telling it what to do with that material. Current guidance suggests resistance work two to three times weekly, built around compound movements, with gradual progression. This matters as much as the protein does.
Tracking is the part you can't skip
Every recommendation above depends on knowing your number. A protein target you never check is a wish.
The problem is that traditional food logging is miserable, and people on GLP-1 medications are already managing injections, side effects, appointments, and cost. Adding fifteen minutes of manual database searching per day is how tracking dies in week three.
This is where Hedgepal fits. Point your camera at the plate and the AI identifies the food and breaks out calories and macros — protein included — in a few seconds. No searching, no scrolling through fourteen versions of "grilled chicken breast."
The other half is that Hedgepal is built around consistency rather than intensity. Streaks and ranks exist because muscle preservation isn't one heroic month at the gym — it's a boring daily record kept for a year. The app's job is making the boring part take thirty seconds so you actually keep doing it.
And when you're staring at a fridge at 8pm wondering what gets you from 60 grams to 100 without making you feel sick, Ask Hedgie is a nutrition chat that will give you a straight answer.
The honest summary
GLP-1 medications work. The weight loss is real and, for a lot of people, life-changing.
What they don't do is manage your protein for you. That part is manual, it's daily, and it's the single highest-yield thing you control while you're on them. Set a target with your clinician, track it honestly, lift twice a week, and you'll come out the other side with the composition you actually wanted.
This article is general information, not medical advice. GLP-1 medications are prescription drugs with real side effects and real contraindications. Talk to your prescribing clinician about your protein target, your dose, and any symptoms you're experiencing — especially if you're losing weight faster than about 1.5 kg per week, struggling to eat at all, or noticing weakness.
