Health
Jul 1, 2026
Why 100 Calories of Protein Doesn't Equal 100 Calories of Carbs — The Thermic Effect of Food and What It Means for Your Calorie Target
Protein burns 20-30% of its own calories just in digestion — eat 100 calories of protein and you net roughly 70-80 calories. Fat burns only 0-3%. This "thermic effect of food" means macronutrient composition changes your effective calorie intake even if the label says the same total. Here's the full TEF breakdown, why it matters for calorie targets, and how high-protein diets exploit it.