Macronutrients ("macros") are the three nutrient groups that provide calories and energy:
- Protein — 4 calories/gram. Builds and repairs muscle, produces hormones and enzymes.
- Carbohydrates — 4 calories/gram. Primary energy source for the brain and muscles.
- Fats — 9 calories/gram. Supports hormone production, vitamin absorption, and cell membranes.
Common Macro Splits
- Balanced: 40% carbs, 30% protein, 30% fat
- Low-carb/keto: 5–10% carbs, 20–25% protein, 65–75% fat
- High-protein (muscle gain): 40% carbs, 35% protein, 25% fat