metabolism
Thermic Effect of Food (TEF)
The energy cost of digesting, absorbing, and metabolizing food — typically 8–15% of calories consumed.
The Thermic Effect of Food (TEF) is the calories your body burns processing what you eat. Protein has the highest TEF (~20–30% of its calories), followed by carbohydrates (~5–10%), then fats (~0–3%). This is one of the mechanisms behind high-protein diets being favorable for fat loss — roughly 20% of each protein calorie is burned simply digesting it.