What is the Thermic Effect of Food?

overweight person sitting holding food


The thermic effect of food (TEF) refers to the energy expenditure or number of calories required for the body to digest, absorb, and process different macronutrients after eating them.


  • Protein has the highest thermic effect – 20-35% of calories burned during digestion. Carbs are 5-15%. Fat is 0-5%.
  • The harder the body must work to digest and metabolize a nutrient, the greater its thermic effect. Protein requires most processing.
  • TEF is one component of metabolism along with BMR and physical activity expenditure. It’s why tracking macros matters beyond just calories.
  • Eating gives your metabolism an added temporary thermic boost based on the energy cost of nutrients. Protein maximizes TEF.


  • Burning 60 of 200 protein calories during digestion due to the 30% thermic effect.
  • A 120 calorie apple will burn 6-18 calories depending on its fiber and carb ratio.

Related Terms

  • Diet induced thermogenesis, metabolism, macronutrients, NEAT

Common Questions

  • Does the TEF affect weight loss? Slightly – higher TEF foods like protein require more energy to process versus fats.
  • How can I maximize the TEF? Eat a high protein diet with fiber-rich low energy density foods. But it’s just one small component.

Do Not Confuse With

  • Basal metabolic rate – Your baseline caloric expenditure at rest rather than after eating.
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