Metabolic Zones
Understanding your caloric needs requires looking at "Zones" rather than a single number. Your TDEE is a moving target influenced by daily activity.
Your TDEE baseline. Weight stays stable.
Sustainable fat loss without muscle waste.
Aggressive deficit. Not recommended for long-term.
Surplus for muscle growth and recovery.
Macronutrient Guide
While calories determine weight, macros determine body composition.
Protein: The Builder
Essential for repairing muscle tissue and keeping you full (high satiety). Aim for 0.8g to 1.2g per lb of body weight during a deficit.
Carbohydrates: The Fuel
The body's primary energy source. High-fiber "complex" carbs provide sustained energy, while "simple" sugars cause insulin spikes.
Fats: The Regulator
Crucial for hormone production and brain health. Focus on "Good" monounsaturated fats (Avocados, Nuts) and avoid trans fats.
Limitations & Context
Calorie formulas are statistical averages. They cannot account for your unique gut microbiome, the thermic effect of specific foods (TEF), or metabolic adaptations from chronic dieting. If you find your progress stalls despite "hitting your numbers," your actual TDEE might be lower than the formula's prediction.
↗ Go Beyond Calories
For a complete metabolic profile, compare these numbers with:
Common Questions
Q: Why am I not losing weight in a deficit?
A: Most common reasons include underestimating portion sizes (liquid calories, oils), water retention from high sodium/workouts, or a temporary metabolic slowdown. Accuracy in tracking is key.
Q: Is a "Calorie a Calorie" for health?
A: For weight loss/gain, yes. For health, no. 100 calories of spinach vs 100 calories of sugar affect your hormones, hunger, and insulin sensitivity very differently.
Q: What is the Thermic Effect of Food (TEF)?
A: This is the energy your body uses to digest food. Protein has the highest TEF (up to 30%), meaning your body "burns" more calories processing steak than it does processing pure fat or sugar.
Q: How do hormones like Leptin affect this?
A: Leptin signals "fullness" to your brain. During long-term deficits, Leptin levels drop, causing increased hunger. Periodic "refeed" days at maintenance can help reset these signals.
Clinical Standard
Mifflin-St Jeor Equation (Validated 1990) | Academy of Nutrition and Dietetics Approved
Editorial Status
Last Updated: January 2026 | Reviewed for Metabolic Accuracy