When it comes to building muscle, all three macronutrients—carbohydrates, proteins, and fats—play a role. But protein is the most important.
Why?
Because it’s the only macronutrient that can create new muscle tissue—or any tissue in the body, for that matter.
When you eat protein-rich foods, your body breaks them down into amino acids, the building blocks of muscle. These amino acids are then used to repair and build new muscle tissue.
The best protein sources come from animal products that are raised on their natural diets, such as grass-fed beef, wild-caught fish, and free-range eggs and chicken. Animal proteins contain all eight essential amino acids, making them “complete proteins”—something our bodies can’t produce on their own.
If you follow a vegetarian or vegan diet, you can still get all essential amino acids by combining different plant-based protein sources.
HOW MUCH PROTEIN DO YOU NEED?
Your protein needs depend on three key factors:
1. Bodyweight – The more you weigh, the more protein you need.
2. Training Intensity – The harder you train, the more protein your body requires for muscle repair and growth.
3. Total Food Intake – Protein alone isn’t enough. Your body also needs the right balance of carbohydrates and fats. Without them, your body may convert protein into fuel instead of using it for muscle-building.
PROTEIN INTAKE GUIDELINES
The classic bodybuilding rule of thumb is 1–1.5g of protein per pound of lean body weight (not total weight).
Lean body mass is your body weight minus your body fat percentage. You can estimate this using calipers or a DXA scan, but if you’re not training for a competition, you can skip this step.
Instead, a simpler rule of thumb is to aim for 0.7–1g of quality, complete animal protein per pound of body weight (excluding plant-based protein sources).
To distribute this intake, divide your daily protein goal by the number of meals you eat (typically 3–6 meals per day).
Summary & Key Take Aways:
Only count complete protein sources. You don’t need to track the protein in foods like rice, pasta, potatoes, or oats.
If you train intensely but don’t get enough protein, you will lose muscle.
When your body lacks dietary protein, it breaks down muscle tissue to get the amino acids it needs. This process, known as catabolism, slows your metabolism and can lead to increased body fat.
During weight training, your body prioritizes fuel sources in this order: carbohydrates → fats → protein. If it runs out of readily available amino acids from dietary protein, it starts breaking down muscle instead.
To maintain and build muscle, you must eat enough protein to support your body’s needs. If you train hard but don’t consume enough protein, you’ll lose muscle and gain fat—simple as that.
No matter your goal, achieving a strong, lean physique comes down to maintaining a balance of low body fat and sufficient lean muscle mass.
If you want to dive deeper into the science of protein intake, I highly recommend this educational article by Precision Nutrition.
