Understanding BMR, TDEE, and Macros
Weight management and body composition goals boil down to energy balance: Energy In vs. Energy Out. To build an effective plan, you need to understand three core pillars: Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), and Macronutrients (Protein, Carbs, Fats).
Advanced Metabolic Formulas Explained
- Mifflin-St Jeor: The modern gold standard for general populations. Calculates BMR using age, gender, height, and weight.
- Harris-Benedict (1984 Revision): A historically popular formula revised for improved accuracy in matching real-world resting metabolic rates.
- Katch-McArdle: The most accurate formula for active individuals and athletes. It ignores gender and instead calculates BMR strictly using lean body mass (requiring body fat percentage input).
Macronutrient Targets for Body Composition
While calories dictate weight loss or gain, macronutrients dictate whether that weight comes from fat or muscle. Different diets serve different fitness pathways: High Protein is optimal for muscle preservation during a cut, Low Carb supports insulin sensitivity, and Ketogenic restricts carbs to induce fat-burning ketosis.