Complete Guide to Macronutrients & Flexible Dieting (IIFYM)
Macronutrients (macros) are the three nutritional pillars your body requires in large amounts to fuel energy production, hormone synthesis, and muscle tissue repair: Protein, Carbohydrates, and Fats.
Calorie Densities per Gram:
1g Protein = 4 kcal | 1g Carbohydrate = 4 kcal | 1g Fat = 9 kcal
1g Protein = 4 kcal | 1g Carbohydrate = 4 kcal | 1g Fat = 9 kcal
Roles of Each Macronutrient
- Protein: Essential for building and repairing muscle, enzyme synthesis, and immune health. High protein intake also provides maximum satiety (fullness).
- Carbohydrates: The primary anaerobic energy source for athletic performance, high-intensity workouts, brain cognition, and muscle glycogen replenishment.
- Fats: Vital for endocrine testosterone/estrogen hormone production, cellular membrane integrity, and fat-soluble vitamin absorption (A, D, E, K).
Frequently Asked Questions
What is "If It Fits Your Macros" (IIFYM)?
IIFYM (flexible dieting) focuses on hitting specific daily targets for protein, carbohydrates, and fats while maintaining overall caloric balance, offering nutritional flexibility without restrictive food bans.
How much protein do I need per pound of body weight?
Most clinical and athletic guidelines recommend 0.7 to 1.0 grams of protein per pound of body weight (1.6 to 2.2 g/kg) for active individuals and resistance trainers.