6 Muscle Building Sources Of Protein
Look anywhere these days and you’re bound to see something about the importance of protein. Are you eating the right kind? Are you eating enough?
To start, let’s talk about what protein is made of: amino acids. These are the molecules your body uses to repair and grow muscle tissue. There are 20 amino acids, and nine of them are considered essential, meaning your body can’t produce them—you have to get them through your diet.
A complete protein has all nine of these essential amino acids, making it ideal for building muscle.
On the other hand, an incomplete protein lacks one or more essential amino acids, so it’s less efficient for muscle repair and growth unless paired with complementary foods in a meal to form complete proteins.
Then there are branch-chain amino acids (BCAAs)—leucine, isoleucine, and valine. These three are particularly important because they play a key role in something called muscle protein synthesis, the process of building new muscle tissue. Among the BCAA’s, leucine is the MVP, triggering the muscle-building switch in your body. We’ll get into that more later, but first, let’s look at 6 of the best sources of protein for muscle building.
1. Chicken Breast
Boneless, Skinless, Chicken Breast
Chicken breast is a top-tier choice for muscle building, and here’s why: first, it’s a complete protein with an excellent amino acid profile, including a solid dose of leucine. Four ounces of chicken breast will get you about 26 grams of protein with only 3 grams of fat, making it one of the leanest and most effective options out there.
The reason we care about how lean a protein source is because we don’t want to have to eat a bunch of extra calories from fat, in order to eat enough protein. All those extra calories, are what lead to weight gain.
Chicken breast is versatile, too. Whether you bake it, grill it, or shred it, chicken breast should be in your muscle-building arsenal.
I know what some of you are thinking… “I don’t want to eat chewy plain chicken breasts” Us neither! Please don’t forget that salt and seasonings have almost no calories, and chicken cooked to 165 degrees won’t turn into jerky.
2. Eggs
Eggs and Egg Whites
Ok moving on to another great source of protein from our chicken friends… Eggs! If they’re good enough for Rocky Balboa, they’re good enough for us. Eggs are often called the "gold standard" of protein because they’re one of the most bioavailable sources of complete protein. Each egg has 6 grams of protein, and the yolk is packed with healthy fats, vitamins, and even some BCAAs.
Since whole eggs aren’t super lean , try combining whole eggs with egg whites. For example, scramble two whole eggs with three egg whites for a high-protein, low-fat breakfast.
3. Shrimp
Fresh or Frozen Shrimp
Ok, let’s jump to another great one: SHRIMP
If you’re looking for a protein source that’s lean, low-calorie, and incredibly nutrient-dense, shrimp is a great option. Four ounces of shrimp delivers 24 grams of complete protein with less than 1 gram of fat. It’s also packed with important micronutrients like selenium and iodine, which support overall health and thyroid function.
Shrimp cooks quickly and works well in stir-fries, salads, or pasta dishes. Plus, its high protein-to-fat ratio makes it ideal for hitting your muscle-building macros without extra calories.
Although shrimp is general considered to be low in mercury, I’d recommend limiting yourself to 2 servings per week, just to be safe.
4. Whey Protein
Whey Protein Isolate
Let’s throw a food in the mix that’s made from milk that’s considered a supplement. Whey protein.
Whey protein is king when it comes to delivering protein conveniently. As a complete protein with a high leucine content, whey is excellent for muscle growth and recovery. It’s also fast-digesting, which makes it perfect for your post-workout shake if you’re not going to have a balanced meal anytime soon.
Whey isolate is especially useful if you’re looking to minimize fat and carbs—it delivers about-25 grams of protein per scoop with minimal calories from carbs or fat. If you’re too busy to cook or you’re always on the go, whey protein is a great option to fill the gaps in your protein game.
5. Lentils and Other Plant-Based Proteins
Lentils & Plant Proteins
Let’s change gears and show some love to our non-meat eating friends. For vegetarians and vegans, plant-based proteins like lentils, chickpeas,beans, and tofu are excellent options. While most plant-based proteins are incomplete, you can combine them with other foods—like rice or quinoa—to form a complete protein.
For example, one cup of cooked lentils has about 18 grams of protein, along with fiber and other essential nutrients. Just be mindful of the additional carbs these sources often come with, especially if you’re tracking your macros.
6. Lean Beef
Lean Beef
Ok, on to our final suggestion for great sources of protein to build muscle. Lean beef.
Beef isn’t just high in protein—it’s also a great source of iron, zinc, and creatine, which support muscle building and overall performance. Lean cuts like sirloin or 90% lean or higher ground beef deliver about 25 grams of protein per 4-ounce serving, along with 2.5 grams of leucine.
Beef has a great protein-to-fat ratio when you choose lean cuts, making it a pretty low-calorie, and satisfying choice for muscle building.
The Importance of Leucine
Let’s pause here to talk more about leucine and why it’s so crucial. Leucine is one of the three BCAAs, and it’s the amino acid responsible for triggering muscle protein synthesis. Think of it as the “on” switch for muscle growth.
Research shows that you need about 2.5-3 grams of leucine per meal to optimize muscle protein synthesis. For perspective:
One scoop of whey protein has about 2.5 grams of leucine.
Four ounces of chicken breast has roughly the same amount.
This is why focusing on high-leucine foods is so important, especially when your goal is to build muscle. As long as you’re eating the sources we’ve talked about in this episode, you’ll be getting plenty of leucine.
A Word on Collagen Protein
Finally, let’s address collagen protein. While it’s currently popular for improving skin, joints, and hair, collagen isn’t ideal for muscle building. It’s an incomplete protein—missing key essential amino acids, including leucine.
And if I’m being honest, the current research suggests it may not be any better at making your skin less wrinkled or your hair more shiny than just eating a high-protein diet in general.
If you to throw some collagen peptides in your coffee for creamer, go for it, but it’s not as a replacement for muscle-building proteins.
Practical Tips:
Here’s how to apply all this:
Spread your protein intake evenly across meals to hit about 0.8-1 grams of protein per pound of body weight daily. If you want to know exactly how much protein and how many calories we recommend, I’ll put a link to our calculator in the description.
Focus on complete protein sources, especially ones high in leucine.
Mix animal-based and plant-based proteins if needed to keep your diet balanced and interesting. Use low-calories sauces and seasons to make your food taste good. No one sticks with a diet they hate.
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