Understanding Energy Expenditure
Your body burns calories continuously—even while sleeping—to maintain vital functions. Understanding your total energy needs is the foundation of any successful nutrition plan.
BMR vs. TDEE
Basal Metabolic Rate (BMR) represents calories burned at complete rest. Total Daily Energy Expenditure (TDEE) includes BMR plus all physical activity—walking, exercising, fidgeting, and digesting food.
Mifflin-St Jeor Equation (Most Accurate):
Men: BMR = 88.362 + (13.397 × weight kg) + (4.799 × height cm) - (5.677 × age)
Women: BMR = 447.593 + (9.247 × weight kg) + (3.098 × height cm) - (4.330 × age)
Calorie Targets for Goals
- Weight Loss: TDEE minus 500 calories/day = ~1 lb loss per week
- Maintenance: Eat at TDEE to maintain current weight
- Weight Gain: TDEE plus 300-500 calories/day for lean muscle gain
Macronutrient Distribution
- Protein (4 cal/g): Essential for muscle repair. Aim for 1.6-2.2g per kg for active individuals.
- Carbohydrates (4 cal/g): Primary fuel for high-intensity exercise and brain function.
- Fats (9 cal/g): Critical for hormone production and vitamin absorption. Never drop below 20% of calories.
Medical Disclaimer: Consult a registered dietitian or physician before making major dietary changes, especially if you have diabetes, thyroid conditions, or eating disorder history.