Weight-loss injections (GLP-1 medications like Ozempic, Wegovy and Mounjaro) are effective — but studies show a large share of the weight lost, often 25-40%, can be muscle rather than fat. Losing muscle slows your metabolism and hurts long-term results. The good news: with the right nutrition and training, you can protect it. Here's how.
Find out exactly how much protein you need to protect your muscle — the calculator does it in 30 seconds.
Open the free nutrition engine →Why muscle is lost on the injections
Rapid weight loss plus a much smaller appetite means many people eat far too little protein. The body then breaks down muscle for energy. Muscle is metabolically active tissue — losing it lowers the calories you burn at rest and makes weight regain more likely later.
Protein is the #1 lever
Aim for roughly 1.6-2.2 g of protein per kg of body weight per day, even (especially) with a reduced appetite. Because you're eating less overall, protein should be the priority at every meal. A daily protein shake makes the target realistic when food volume is low. Use the calculator for your exact number.
Add resistance training 2-3× a week
Lifting weights (or bodyweight/bands) tells your body to keep the muscle it has. Even short, simple sessions make a big difference in how much of your weight loss comes from fat versus muscle.
Don't cut calories too aggressively
The injection already reduces appetite — there's no need to slash calories further. Very low intake accelerates muscle loss and nutrient gaps. Eat enough, prioritize protein, and let the medication do its part.
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How much protein should I aim for on the injections?
Roughly 1.6-2.2 g/kg of body weight per day. With a small appetite, a protein shake helps you reach it.
Will I regain the weight after stopping?
Preserving muscle during the loss (protein + training) protects your metabolism and makes keeping the result far more likely. Discuss stopping with your doctor.
Do I need a protein shake?
Not mandatory, but when appetite is low it's the easiest way to hit your protein target without feeling overfull.