Calorie Tracking
The Truth About Calories In vs Calories Out
The truth about calories in vs calories out and why it is more complex than a simple equation. Understanding metabolic adaptation.
The calories in vs calories out model is both fundamentally correct and incomplete.
Calories in is not a fixed input. A 500 calorie meal of chicken and vegetables produces a different hormonal response than 500 calories of white bread.
Calories out is dynamic. Your TDEE is influenced by your calorie intake.
The thermic effect of food varies by nutrient. Protein has about 20 to 30 percent thermic effect.
Non exercise activity thermogenesis, NEAT, is the energy from fidgeting, standing, and daily movement.
Exercise increases calorie burn, but the effect on total expenditure is often smaller than expected.
The gut microbiome affects how many calories you extract from food.
Hormones play a significant role. Thyroid hormone regulates metabolic rate.
Sleep deprivation affects both sides. Poor sleep increases hunger hormone ghrelin.
The practical implication is to use the model as a framework for tracking and adjusting.