TEF Calculator
Calculate how many calories your body burns digesting food
Your TEF Results
Track Your TEF Automatically
AI Food Coach calculates your thermic effect dynamically from every meal you log — not a flat estimate.
What is the Thermic Effect of Food?
The Thermic Effect of Food (TEF), also known as diet-induced thermogenesis (DIT), is the energy your body expends to digest, absorb, transport, and metabolize the nutrients in your food. It’s one of three components of your total daily energy expenditure (TDEE), alongside your Basal Metabolic Rate (BMR) and physical activity.
TEF typically accounts for 5–15% of your total calorie intake. The exact percentage depends primarily on the macronutrient composition of your diet — not the total calories. A 2,000 kcal high-protein diet burns significantly more through TEF than a 2,000 kcal high-fat diet.
TEF by Macronutrient
Each macronutrient requires a different amount of energy to process. This is why your macro ratio matters just as much as your total calories:
| Macronutrient | Thermic Effect | Research Range | Why |
|---|---|---|---|
| Protein | 20–30% | Westerterp 2004 | Amino acid processing, gluconeogenesis, urea synthesis |
| Carbohydrates | 5–10% | Tappy 1996 | Glycogen conversion, insulin response, glucose transport |
| Fat | 0–5% | Blaxter 1989 | Minimal processing needed — dietary fat is already close to storage form |
| Alcohol | 10–30% | Suter 1997 | Detoxification priority in liver, inefficient metabolism |
Protein has the highest thermic effect because your body must break peptide bonds, convert amino acids, synthesize new proteins, and convert excess to glucose through gluconeogenesis. This process is energetically expensive — your body uses 20–30% of protein’s calories just to process it.
How to Increase Your TEF
Since TEF is determined by what you eat, you can influence it through dietary choices:
- Increase protein intake: Swapping 100 kcal of fat for 100 kcal of protein burns ~22 extra calories through TEF alone. Over a year, that adds up.
- Eat whole foods: A 2010 study (Barr & Wright) found that whole foods have ~50% higher thermic effect than processed equivalents. A whole-grain sandwich burned nearly twice the TEF of a white-bread sandwich with the same calories.
- Don’t worry about meal timing: Whether you eat 2 or 6 meals per day, your total daily TEF is the same — it depends on total macros consumed, not meal frequency.
The single most impactful change is increasing protein. A shift from 15% to 30% protein can increase daily TEF by 60–100 kcal — equivalent to a 20-minute walk.
TEF and Weight Loss
TEF creates “free” calorie burn — energy your body uses just processing the food you already eat. While individual meals have small TEF differences, the cumulative effect across months is meaningful:
Real-world example: A high-protein diet (30% protein, 40% carbs, 30% fat) at 2,000 kcal produces ~260 kcal/day TEF. A high-fat diet (15% protein, 35% carbs, 50% fat) at 2,000 kcal produces only ~155 kcal/day TEF. That’s a 105 kcal/day difference — or ~5 kg of body weight per year, all else being equal.
This is the protein leverage hypothesis: high-protein diets improve weight loss not just through satiety, but through a genuine metabolic advantage. Your body burns more calories processing protein-rich foods.
Most calorie trackers ignore TEF or use a flat 10% estimate. AI Food Coach calculates TEF dynamically from your actual macros, giving you a more accurate calorie target that accounts for this hidden calorie burn.
Our Formula
This calculator uses midpoint values from peer-reviewed research to estimate TEF per macronutrient:
The coefficients (25%, 7.5%, 2.5%) represent the midpoint of each macronutrient’s thermic range (20–30%, 5–10%, 0–5%). These values are derived from:
- Hall KD (2010) — “Predicting metabolic adaptation, body weight change, and energy intake in humans.” Am J Physiol Endocrinol Metab.
- Westerterp KR (2004) — “Diet induced thermogenesis.” Nutr Metab.
- Blaxter KL (1989) — Energy Metabolism in Animals and Man. Cambridge University Press.
For a complete overview of how AI Food Coach uses these calculations, see our methodology and sources page.
