What Are Macronutrients?
Macronutrients — protein, carbohydrates, and fats — are the three main categories of nutrients your body uses for energy, tissue repair, and vital functions. Every food you eat contains some combination of these three, and understanding how much of each you need is one of the most practical things you can do to improve your results in the gym and in your health overall.
Step 1: Calculate Your Total Daily Energy Expenditure (TDEE)
Before you split macros, you need to know how many total calories to aim for. Your TDEE accounts for your basal metabolic rate (BMR) plus your activity level.
A common starting formula (Mifflin-St Jeor) for BMR:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Multiply your BMR by an activity factor: 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active).
Step 2: Set Your Calorie Target Based on Your Goal
| Goal | Calorie Adjustment |
|---|---|
| Fat Loss | TDEE minus 300–500 kcal/day |
| Maintenance | Equal to TDEE |
| Muscle Gain | TDEE plus 200–350 kcal/day |
Avoid extreme deficits or surpluses — they tend to cause muscle loss or excess fat gain respectively.
Step 3: Set Your Protein Target First
Protein is the most important macro for body composition. It supports muscle repair, preserves lean tissue during a cut, and keeps you fuller for longer.
- Fat loss: 1.8–2.2g per kg of bodyweight
- Maintenance/muscle gain: 1.6–2.0g per kg of bodyweight
Each gram of protein contains 4 calories. Multiply your protein grams by 4 to find how many calories protein accounts for.
Step 4: Allocate Fats
Dietary fat supports hormone production, joint health, and vitamin absorption. Aim for 25–35% of your total calories from fat. Each gram of fat contains 9 calories.
Step 5: Fill the Remainder with Carbohydrates
After accounting for protein and fat calories, assign the remaining calories to carbohydrates. Carbs fuel your workouts and support recovery — don't cut them too aggressively if you train hard. Each gram of carbohydrate contains 4 calories.
Example Calculation
A 30-year-old woman, 65 kg, moderately active, aiming for fat loss with a 2,000 kcal target:
- Protein: 65 × 2.0 = 130g → 520 kcal
- Fat: 30% of 2,000 = 600 kcal → 67g
- Carbs: 2,000 − 520 − 600 = 880 kcal → 220g
Tracking Tips
- Use a food tracking app to log meals and stay within your targets.
- Weigh food raw using a kitchen scale for accuracy — volumes can be misleading.
- Reassess your macros every 4–6 weeks as your weight and activity level change.
- Prioritize whole, minimally processed foods to hit your targets with better micronutrient density.
The Bottom Line
Macro tracking doesn't need to be a lifelong obsession, but spending a few months calculating and logging your intake can give you a strong intuitive sense of portion sizes and food composition — knowledge that pays dividends long after you stop counting.