The thermic effect of food is the energy used to digest, absorb, and process nutrients; estimates vary by meal and person. This page provides a definition and practical context; it is not an individualized medical or nutrition prescription. Use the related tools and guides for calculations or programming decisions rather than treating a glossary definition as a result.
Why protein moves the needle more than meal timing
Of the three macronutrients, protein has by far the highest thermic cost, roughly 20 to 30% of its calories are spent digesting and processing it, compared to roughly 5 to 10% for carbohydrates and 0 to 3% for fat. This means a higher-protein diet burns modestly more calories through digestion alone than a lower-protein diet at the same total calories, a small but real contributor to why higher protein intakes tend to support fat loss and satiety better than macronutrient splits skewed toward fat or carbs. Meal timing and frequency, by contrast, have little effect on total daily thermic effect once total intake and macro split are held constant.