Why You Should Prioritize Protein on a GLP-1 Diet
- Jennifer Hardy
- Apr 19
- 5 min read
If you're on a GLP-1 medication—or thinking about starting one—you’ve probably heard about the importance of protein along with appetite changes. For many, hunger fades, cravings disappear, and meals become more of a “should” than a “want.”
While that can be a welcome shift when weight loss is the goal, it comes with one big risk: not getting enough protein, which can lead to muscle mass loss, fatigue, and slower metabolism.
Whether you're already taking semaglutide or tirzepatide, or you're prepping for that first injection, it's worth understanding why protein becomes a top priority from day one. Plus, we'll help you shop for and manage your protein intake.
Why Protein Matters More Than Ever
When you're in a calorie deficit, your body will pull energy from wherever it can. Without enough protein, your body may start breaking down muscle mass along with fat.
That’s not just a cosmetic concern—it’s a metabolic one. Muscle helps burn calories, stabilizes blood sugar, and supports long-term weight management. If you lose too much of it, your metabolism can slow, energy dips, and physical strength declines.
Here's how it works:
Your body needs a constant supply of amino acids (the building blocks of protein) to maintain muscles, organs, and other vital systems. If you’re not eating enough protein, your body can’t find those amino acids from food—so it starts breaking down your muscle tissue to get what it needs.
That’s called muscle catabolism, and it’s common during weight loss if protein intake is too low.
On the flip side, if you do eat enough protein, your body is more likely to preserve muscle and burn stored fat for energy instead. Combine that with some strength training or resistance movement, and you’re sending a clear signal: “keep the muscle, lose the fat.”
GLP-1 medications don’t inherently protect muscle. You have to do that yourself, with your protein intake and your fitness levels.
That's just one of the many reasons protein benefits everyone on a GLP-1 diet.
Benefit | Why It Matters on GLP-1 Diets |
Muscle preservation | Prevents loss of lean mass during calorie deficit |
Satiety | Reduces hunger, helps sustain calorie reduction |
Weight management | Promotes fat loss while minimizing muscle loss |
Blood sugar stability | Slows glucose absorption, supports glycemic control |
Metabolic health | Maintains metabolism during weight loss |
How Much Protein Do You Need on a GLP-1 Diet?
When I first started taking tirzepatide, I saw a blank statement of "Get 120 grams of protein a day." That seemed impractical if not impossible. I started working with a nutritionist (shout out to Ashley of Legg Day Fitness!) and we worked out a more science-based equation based on my weight.
As a general guideline, you want to get about .36 grams of protein per pound of body weight.
150-pound person — 54 grams
200-pound person — 72 grams
250-pound person — 90 grams
Even with that guidance, it's best to talk to your doctor or a nutrition counselor about what works best for you.
I'm not a doctor, but I know what works best for me is between 80 grams and 100 grams per day. Protein makes up 25% of each meal, with snacks leaning heavily on protein.
That factors in the protein I need to protect muscle, plus the boost I want to build muscle during fitness sessions.
What Type of Protein to Choose
If you're preparing to start a GLP-1 medication or looking to get on the protein train, now is the time to plan your protein strategy. Think about how you'll get quality protein into your body, especially on days when you don’t feel hungry.
Not all proteins are made the same, and some sources with high levels of protein also pack on calories and added sugars or fats.
Here's a list of food options that are in protein and offer a full range of essential amino acids (aka “complete proteins”), plus they’re usually easy to digest and low in unnecessary extras like sugar or saturated fat.
Eggs
Greek yogurt (especially plain, high-protein versions)
Chicken breast, turkey, lean beef
Fish and seafood
Cottage cheese
Whey or casein protein powders
Fairlife milk or Core Power shakes
Tofu, tempeh, and edamame (plant-based complete proteins)
Because you’re likely eating less, you want maximum protein in minimum volume. That’s why lean animal proteins, dairy, eggs, and quality protein supplements are your best bets. You’re not just trying to eat “some protein”—you’re trying to protect muscle with what little you can eat.
Trust me, there will be days that even drinking a protein shake is a two-meal challenge. My secret weapon for added protein when the appetite is gone? Bone broth.
Common Protein Mistakes People Make on GLP-1 Diets
While trying to find the protein sweet spot on your GLP-1 diet, you'll likely stumble. Here are some common ways that mistakes happen.
Skipping meals entirely: You might not feel hungry, but going all day without eating means you’re also skipping protein.
Snacking on carbs or “light” foods: Crackers, popcorn, fruit—they’re fine, but they won’t protect your muscle mass. Always pair snacks with protein.
Assuming you're eating enough: On GLP-1s, it’s easy to underestimate your intake. Track for a few days—you might be surprised how low your protein is.
Eating ONLY protein: When the appetite is small, you might think there's only room for protein. Protecting muscle is important, but you also need fiber, healthy fats, and complex carbs for your body to function well and limit side effects.
Getting the right balance of foods is also important to target the side effects. While GI distress, fatigue, and lightheadedness can be legit side effects of a GLP-1 medication, they are also signs of not eating enough and dehydration.
Is the GLP-1 Diet Essentially the Same as a Keto or Low-Carb Diet?
No, the GLP-1 diet isn’t the same as keto or low-carb. GLP-1 medications reduce appetite and food intake, but they don’t restrict carbs or fat by design. Keto limits carbs to force the body into ketosis; GLP-1s work hormonally to control hunger.
That said, both approaches emphasize protein to preserve muscle, but the GLP-1 lifestyle is more about balance and intentional nourishment than strict macros.
Your Protein Prowess
Whether you’re just starting a GLP-1 medication or adjusting to life with a smaller appetite, protein needs to be part of the plan. It helps preserve muscle mass, keeps your metabolism stable, and gives your body the support it needs as the number on the scale drops.
No, you don’t need to eat like a bodybuilder. But being intentional with your protein intake, using protein supplements when needed, and building meals that prioritize quality over quantity can make all the difference in how you feel—and how you maintain progress.
This journey is about more than just eating less. It’s about fueling your body smarter. Visit our GLP-1 Product Shop to see our top pick of proteins for your journey.
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