More Than Just Muscle
Most people associate protein with building muscle — and they're right. But protein's role goes far deeper. Every enzyme in your body is a protein. Your immune antibodies are proteins. Hormones like insulin and growth hormone are proteins. Your skin, hair, and connective tissue are made of protein. It is, quite literally, the material your body is built from.
What Protein Does
Builds and repairs muscle — When you exercise (or even just move), muscle fibers experience small tears. Protein provides the amino acids to repair and reinforce them, making you stronger over time.
Keeps you full — Protein is the most satiating macronutrient. It suppresses ghrelin (the hunger hormone) more effectively than carbs or fat, and it triggers the release of satiety hormones like PYY and GLP-1. Studies consistently show that higher-protein meals lead to lower calorie intake later in the day.
Supports fat loss — Your body burns more calories digesting protein than carbs or fat (thermic effect of food: ~25–30% vs 6–8% vs 2–3%). Protein also helps preserve muscle mass during a calorie deficit, ensuring the weight you lose is mostly fat, not muscle.
Regulates hormones and enzymes — Dozens of hormones are made from amino acids, including those that regulate metabolism, sleep, mood, and stress response.
Supports immunity — Antibodies that fight infection are proteins. Chronically under-eating protein impairs immune function.
How Much Do You Need?
For general health: 0.8g per kilogram of body weight is the minimum.
For active people and those trying to change body composition: 1.6–2.2g per kilogram is supported by current research. A 70kg person doing regular exercise should aim for 110–155g daily.
Best Sources
- Animal: chicken breast, turkey, eggs, Greek yogurt, cottage cheese, salmon, tuna, lean beef
- Plant: tofu, tempeh, edamame, lentils, black beans, quinoa, seitan
Signs You're Not Eating Enough
- Constant hunger even after eating
- Slow recovery from exercise or soreness that lingers
- Difficulty maintaining or building muscle
- Frequent cravings for sweets or salty snacks
- Brittle nails or thinning hair
The Bottom Line
If you can only focus on one macro, make it protein. Hit your daily target, distribute it across 3–4 meals, and let the rest of your nutrition follow naturally.