A few months ago a friend told me he’d been on a GLP-1 since February. Down fourteen pounds. He looked good in the way the scale wants you to look good.
He also told me, in the same conversation, that the easy hill on his Sunday bike ride wasn’t easy anymore. His top set at the gym was slower than it’d been at Christmas. His doctor had told him to eat protein and his tracking app had given him a number. Eighty grams a day. He was hitting it most days.
He was still losing strength.
That number is the problem.
Where the standard number comes from
Most weight loss apps and most published guides for GLP-1 users (Ozempic, Wegovy, Mounjaro, Zepbound) land at somewhere between 0.4 and 0.5 grams of protein per pound of bodyweight per day. For a 180lb person that’s around 70-90 grams.
The number isn’t wrong. It’s just not for you.
That guidance is calibrated for the average sedentary adult who is trying to keep enough muscle to walk up the stairs and not break a hip a decade from now… fine for that. It is not calibrated for someone who plays pickleball at a real intensity twice a week, or runs, or hikes with a pack, or trains, or otherwise asks their body to do things.
If you fit any of that, your floor moves. Two reasons. One, you’re eating less food on a GLP-1 so the percentage of protein in any given meal has to be higher just to land at the same gram total. Two, fast weight loss is the exact condition under which the body strips lean tissue most aggressively. Combine those… it goes up. Not down.
What the actual number looks like
The International Society of Sports Nutrition has been clear for years. Physically active adults need roughly 0.6 to 0.9 grams of protein per pound of bodyweight per day. That guidance was already on the conservative side for someone in a calorie deficit. The same person now losing 1.5% of their bodyweight per week on a medication? Same direction. Goes up.
So the working number for somebody who trains and is on a GLP-1 sits somewhere in the 0.7 to 0.9 grams per pound range. For my friend, who’s around 165lbs, that’s 115-150 grams a day. The mainstream app he was using told him 75. The gap is real, and it’s roughly the difference between four scoops of whey… every day… for the entire run of the medication. Compounded across four months that’s why people end up the medication leaner on paper but visibly deflated.
A peer-reviewed review by Cava and colleagues in Advances in Nutrition concluded that during caloric restriction, bumping protein toward the higher end is one of the few interventions that actually preserves lean mass (Cava, Yeat, and Mittendorfer, 2017). That study isn’t GLP-1 specific because it predates the wave. The mechanism is the same.
You don’t need to chase the upper end. Past 1 gram per pound, additional protein doesn’t do much for muscle retention, it just costs you more grocery money. The bottom of the range is where the leverage actually sits.
The part nobody mentions
Here’s what almost nobody is telling you. The number isn’t supposed to stay the same.
A GLP-1 user who started at 220lbs and is now at 195 has a different protein target than three months ago. Most apps don’t recalculate. They show you the number you set on day one, even though the body that number was calculated for is gone.
If your target is 0.8 grams per pound and you’re losing 1-1.5% of your bodyweight per week, your daily protein number drops by a few grams every couple of weeks. Sounds tiny. Across an eight month protocol it adds up to a 15-20 gram swing… which can be the difference between holding the strength you have and watching it walk out the door.
The fix isn’t complicated. Recalculate every time you log a new weight. The math is one multiplication. Most apps just don’t bother.
This is one of the structural differences in how TrakMac handles macro targets. Body composition signals come from your training profile at onboarding. The protein number recalibrates as your weight trend moves. The next post in the series goes deeper on the recalibration mechanic.
What to actually do this week
If you’re on a GLP-1 and you care about staying strong, three concrete moves…
Do the math. Current bodyweight in pounds, multiply by 0.7 for the floor, multiply by 0.9 for the ceiling. Aim somewhere in the middle.
Spread it across the day. Three or four servings of 30-50 grams works better than one giant chicken breast at 8pm. GLP-1s slow gastric emptying, which means smaller protein hits are easier to actually finish than one huge meal. Your body absorbs them more efficiently anyway.
And track it. Most people on a GLP-1 who think they’re hitting protein are off by 30-50 grams a day. Low. The medication blunts hunger so quickly that you stop noticing how little you actually ate. A five second voice log per meal closes that gap fast.
If your current app gives you a number on day one and never moves it, or treats your protein number the same whether you do hot yoga twice a week or front squat 200 pounds… that is the wrong tool for the job.
Download TrakMac
I built TrakMac because the apps I’d been handed didn’t account for any of this. Voice-first logging. Training-aware protein targets. A number that recalibrates as your bodyweight moves. iOS first, live on the App Store now.
If that sounds useful… Download TrakMac free.