📋 Table of Contents
What Are Macros?
Macronutrients ("macros") are the three primary classes of nutrients that supply energy to the body:
- Protein: 4 calories per gram — builds and preserves muscle, highly satiating
- Carbohydrates: 4 calories per gram — primary fuel for the brain and high-intensity exercise
- Fat: 9 calories per gram — hormone production, fat-soluble vitamin absorption, sustained energy
Tracking macros (often called IIFYM — If It Fits Your Macros) means monitoring grams of each nutrient, not just total calories. This allows precise manipulation of body composition.
Protein, Carbs & Fat Explained
Protein: The Priority Macro
Protein is the most critical macro for anyone with physique goals. It provides amino acids for muscle protein synthesis, is the most satiating macro per calorie, and has the highest thermic effect of food (20–30% of protein calories are burned in digestion).
General protein targets: 0.7–1.0g per pound of bodyweight (1.5–2.2g per kg) for active individuals. Sedentary adults can maintain muscle on 0.5–0.7g/lb.
| Protein Source | Protein (per 100g) | Calories (per 100g) |
|---|---|---|
| Chicken breast (cooked) | 31g | 165 |
| Canned tuna (in water) | 26g | 116 |
| Greek yogurt (0% fat) | 10g | 59 |
| Eggs (whole) | 13g | 155 |
| Cottage cheese (low-fat) | 12g | 98 |
| Lentils (cooked) | 9g | 116 |
| Whey protein powder | 80–90g | 380–400 |
Carbohydrates: Fuel and Performance
Carbs are not the enemy — they're the body's preferred fuel for exercise and the brain's primary energy source. Quality matters more than quantity: complex carbs (oats, rice, potatoes, vegetables) provide fiber and stable energy; simple sugars cause rapid spikes.
Fat: Essential, Not Optional
Dietary fat is required for testosterone production, fat-soluble vitamins (A, D, E, K), and cell membrane integrity. Dropping below 20% of calories from fat for extended periods can suppress hormones. Focus on unsaturated fats (olive oil, avocado, nuts, fish) and limit saturated fat.
Macro Ratios by Goal
| Goal | Calorie Adjustment | Protein | Carbs | Fat |
|---|---|---|---|---|
| Fat Loss (Cutting) | −300 to −500 kcal/day | 40% | 30% | 30% |
| Maintenance / Recomposition | TDEE | 30–35% | 35–40% | 25–30% |
| Muscle Gain (Bulking) | +250 to +500 kcal/day | 25–30% | 45–50% | 20–25% |
| Athletic Performance | TDEE | 20–25% | 55–60% | 20–25% |
| Ketogenic (low-carb) | Variable | 25–30% | 5% | 65–70% |
How to Calculate Your Macros: Step-by-Step
- Calculate your TDEE — Total Daily Energy Expenditure. Use a calorie calculator that accounts for your BMR (Mifflin-St. Jeor formula) × activity multiplier (sedentary 1.2 → very active 1.9).
- Set your calorie target — For fat loss: TDEE − 300–500 kcal. For muscle gain: TDEE + 250–500 kcal. For maintenance: TDEE.
- Calculate protein grams — Multiply bodyweight (lbs) by 0.7–1.0. Each gram = 4 calories.
- Calculate fat grams — Aim for 25–35% of calories. Each gram = 9 calories.
- Fill remaining calories with carbs — (Total calories − protein calories − fat calories) ÷ 4 = carb grams.
Example: 175 lb Person, Fat Loss Goal
- TDEE: 2,600 kcal → Target: 2,200 kcal (−400 deficit)
- Protein: 175g × 1 = 175g → 175 × 4 = 700 kcal
- Fat: 30% of 2,200 = 660 kcal ÷ 9 = 73g
- Carbs: (2,200 − 700 − 660) ÷ 4 = 840 ÷ 4 = 210g
- Result: 175g protein / 210g carbs / 73g fat
Tracking Tips & Apps
- MyFitnessPal — Largest food database, barcode scanner, easy logging
- Cronometer — More accurate micronutrient tracking, favored by dieticians
- MacroFactor — Adjusts targets automatically based on your actual weight trend
- Kitchen scale — Most important tool; volume measurements are unreliable for calorie tracking
- Consistency over precision — Hitting within 10% of targets consistently beats perfect tracking once a week