Understanding Macronutrients
Macronutrients are the three main nutrients that provide energy (calories) to your body: protein, carbohydrates, and fat. Each plays unique and essential roles in your health, performance, and body composition.
Protein
Protein is essential for building and repairing muscle tissue, producing enzymes and hormones, and supporting immune function. Each gram of protein provides 4 calories.
- Muscle Building: Provides amino acids for muscle protein synthesis
- Satiety: Most filling macronutrient, helps control hunger
- Thermic Effect: Burns more calories during digestion (20-30%)
- Sources: Meat, fish, eggs, dairy, legumes, tofu
Carbohydrates
Carbohydrates are your body's preferred energy source, especially for high-intensity exercise and brain function. Each gram provides 4 calories.
- Energy: Primary fuel for muscles and brain
- Glycogen: Stored in muscles for exercise performance
- Fiber: Important for digestive health (non-caloric)
- Sources: Grains, fruits, vegetables, legumes, dairy
Fat
Dietary fat is crucial for hormone production, nutrient absorption, and cell membrane health. Each gram provides 9 calories, making it the most energy-dense macronutrient.
- Hormones: Essential for testosterone and estrogen production
- Absorption: Required for vitamins A, D, E, and K
- Satiety: Slows digestion and increases fullness
- Sources: Oils, nuts, seeds, avocado, fatty fish, eggs
Key Insight: While all three macronutrients are important, protein is often prioritized because adequate intake supports muscle retention during weight loss and muscle growth during bulking phases.
How to Calculate Your Macros
Calculating your macros involves determining your total daily energy expenditure (TDEE), adjusting for your goals, and then distributing those calories among protein, carbs, and fat.
Step 1: Calculate Your BMR
Basal Metabolic Rate (BMR) is the number of calories your body burns at rest. We use the Mifflin-St Jeor equation:
Men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5Women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161Step 2: Apply Activity Multiplier
Multiply your BMR by an activity factor to get your TDEE:
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, desk job |
| Lightly Active | 1.375 | Light exercise 1-3 days/week |
| Moderately Active | 1.55 | Moderate exercise 3-5 days/week |
| Very Active | 1.725 | Hard exercise 6-7 days/week |
| Extra Active | 1.9 | Very hard exercise, physical job |
Step 3: Adjust for Your Goal
- Weight Loss: Subtract 500 calories for ~1 lb/week loss
- Maintenance: Keep TDEE as calculated
- Muscle Gain: Add 200-300 calories for lean gains
Step 4: Distribute Macros
Using your target calories, calculate grams for each macro:
Protein (g) = (Target Calories x Protein %) / 4Carbs (g) = (Target Calories x Carb %) / 4Fat (g) = (Target Calories x Fat %) / 9Diet Types Explained
Different macro ratios support different goals and preferences. Here's what each diet type offers and who it's best suited for.
Balanced Diet (30% P / 40% C / 30% F)
The most sustainable approach for the general population. Provides adequate protein for muscle maintenance, enough carbs for energy, and sufficient fat for hormone health.
Best for: General health, beginners, sustainable long-term eating
Low Carb (35% P / 25% C / 40% F)
Reduces carbohydrate intake while increasing protein and fat. Can improve insulin sensitivity and reduce hunger for some individuals.
Best for: Blood sugar control, those who feel better with fewer carbs, moderate activity
High Protein (40% P / 35% C / 25% F)
Maximizes protein intake to support muscle building, enhance satiety during weight loss, and increase thermic effect of food.
Best for: Muscle building, weight loss while preserving muscle, athletes
Keto (25% P / 5% C / 70% F)
Very low carb, high fat diet that shifts the body into ketosis. Carbs are typically limited to 20-50g per day.
Best for: Those who thrive on low carb, certain medical conditions, appetite control
Note: The best diet is one you can stick to consistently. If you struggle with a particular macro split, try a different approach. Adherence matters more than optimization.
How We Calculate Macros
Our macro calculator uses evidence-based formulas and methodology to provide accurate, personalized recommendations.
Calculation Methodology
1. Mifflin-St Jeor Equation
We use the Mifflin-St Jeor equation for BMR calculation, which is considered the most accurate for most populations:
Men: BMR = (10 x weight[kg]) + (6.25 x height[cm]) - (5 x age) + 5Women: BMR = (10 x weight[kg]) + (6.25 x height[cm]) - (5 x age) - 1612. Activity Factor Application
TDEE is calculated by multiplying BMR by the activity factor:
TDEE = BMR x Activity Factor3. Goal-Based Adjustment
Calories are adjusted based on your selected goal:
Weight Loss: TDEE - 500 calories (1 lb/week deficit)Maintenance: TDEE (no adjustment)Muscle Gain: TDEE + 300 calories (lean bulk)4. Macro Distribution
Macros are calculated using caloric values per gram:
Protein: 4 calories per gramCarbohydrates: 4 calories per gramFat: 9 calories per gramAccuracy Considerations
- Individual metabolism can vary by 10-15% from calculated values
- Track your progress for 2-3 weeks before making adjustments
- Recalculate when weight changes by 10+ lbs
- Activity levels are estimates; adjust based on actual results