What is the thermic effect of fat?

The thermic effect of food (TEF) refers to the increase in metabolic rate that occurs after the ingestion of food, with different macronutrients exhibiting varying thermic effects. Fats generally have a lower thermic effect compared to carbohydrates and proteins.

The thermic effect of fat is typically around 2-3%. This means that when fat is consumed, approximately 2-3% of the calories from fat will be expended in the process of digestion, absorption, and metabolism. This relatively low percentage reflects the efficiency of fat metabolism, as fats are a more energy-dense macronutrient and require less energy to process compared to carbohydrates and proteins, which can have thermic effects ranging from 5% to 30%.

This makes the identified range of 2-3% for the thermic effect of fat the most accurate and aligned with current scientific understanding of macronutrient metabolism.