TEFLab

Thermic Effect of Food (TEF)

Roughly 10% of daily calories are spent on digestion.

Daily calories

TEF (kcal burned digesting)

220

Thermic Effect of Food ≈ 10% of daily intake.

What you entered

Daily calories: 2200

1
TEF ≈ 10% of daily calories
2200 × 0.10= 220 kcal

Result

TEF (kcal burned digesting): 220

Digesting 2200 kcal worth of food burns roughly 220 kcal on its own.

Thermic effect of food by daily calorie intake

Digesting food costs energy. The thermic effect of food is roughly 10% of total intake for a mixed diet, and it counts toward your daily burn.

Daily intake	Thermic effect	Share of intake
1,500 kcal	150 kcal	10%
1,800 kcal	180 kcal	10%
2,000 kcal	200 kcal	10%
2,200 kcal	220 kcal	10%
2,500 kcal	250 kcal	10%
3,000 kcal	300 kcal	10%

The 10% figure is a mixed-diet average. Protein alone runs 20 to 30%, carbohydrate 5 to 10%, and fat 0 to 3%, so a higher-protein diet raises the total. General wellness information only, not medical advice. Discuss any health decision with a qualified clinician.

Digestion itself burns calories

Your body spends energy breaking down, absorbing, and processing the food you eat — this 'cost of digestion' is the thermic effect of food, and it varies by macronutrient (protein has the highest thermic cost, fat the lowest).

Why it's usually a minor factor

TEF typically accounts for around 10% of total calories burned in a day — real but modest compared to basal metabolism and activity, which is why it's often folded into TDEE estimates rather than tracked separately.

Frequently asked questions

What is the thermic effect of food?

TEF is the energy your body uses to digest, absorb, and process nutrients. It accounts for about 10% of total daily energy expenditure. Protein has the highest TEF (20–30% of its calories are burned during digestion), followed by carbs (5–10%), then fat (0–3%). This is why high-protein diets have a slight metabolic advantage.

Can eating more protein boost your metabolism?

Slightly, through TEF. Replacing 100 calories of fat (TEF: ~3 cal) with 100 calories of protein (TEF: ~25 cal) burns ~22 extra calories. Over a full day, shifting to 30% protein from 15% might burn 50–100 extra calories through TEF alone. Real but modest — it won't overcome a calorie surplus.

Does meal frequency affect TEF?

No. Total TEF depends on what and how much you eat, not how many meals you split it into. Six small meals burn the same TEF as two large meals with the same total calories and macros. The 'eat small frequent meals to boost metabolism' advice is a myth when it comes to TEF.