How many calories does digesting food take? Unpacking the Thermic Effect of Food

November 5, 2025 •

2 min read

On average, the human body expends roughly 10% of its total daily energy expenditure just to process and absorb the food we eat. This process, scientifically known as the Thermic Effect of Food (TEF), is the answer to how many calories does digesting food take and varies based on your meal's composition.

Quick Summary

The Thermic Effect of Food (TEF) is the energy cost of digestion, absorption, and nutrient storage. This energy expenditure varies significantly by macronutrient, with protein requiring the most energy to process, offering a modest metabolic advantage.

Key Points

Thermic Effect of Food (TEF): This is the scientific term for the energy your body burns to digest, absorb, and process nutrients from food.
Macronutrients Matter: The energy cost of digestion varies significantly by macronutrient; protein requires the most energy (20-30%), followed by carbohydrates (5-10%), and then fats (0-3%).
Protein's Advantage: Because of its high TEF, a diet rich in lean protein can offer a slight metabolic edge by increasing the calories burned during digestion.
Whole vs. Processed Foods: Minimally processed, whole foods generally have a higher TEF than highly processed foods because your body has to work harder to break them down.
It's Modest, Not Magical: While TEF is a real factor in metabolism, its effect on overall calorie burn is relatively small and should not be relied upon as the sole strategy for weight loss.
The 'Negative Calorie' Myth: The idea that certain foods, like celery, burn more calories to digest than they contain is a misconception. The TEF is never high enough to create a net negative calorie effect.

The Science Behind the Thermic Effect of Food (TEF)

The Thermic Effect of Food (TEF), also known as diet-induced thermogenesis (DIT) or specific dynamic action (SDA), is the increase in metabolic rate after eating. It's a key part of your total daily energy expenditure (TDEE), alongside your basal metabolic rate (BMR) and physical activity.

The Physiological Process of Digestion

Digestion is a multi-step process that requires energy for tasks like chewing, swallowing, gastric churning, enzyme production, peristalsis, and nutrient transport and storage.

Macronutrients: Not All Calories are Equal

The composition of your meal significantly impacts how many calories does digesting food take. Different macronutrients require varying amounts of energy to process.

TEF Comparison by Macronutrient

This table shows the approximate percentage of energy used to digest each macronutrient.


Macronutrient	Calories per gram	Thermic Effect of Food (TEF)	Net Calories per 100 kcal consumed
Protein	4 kcal	20–30%	70–80 kcal
Carbohydrates	4 kcal	5–10%	90–95 kcal
Fats	9 kcal	0–3%	97–100 kcal

Factors Influencing Your Personal TEF

Beyond macronutrients, factors like age, body composition, food processing, meal timing, and even certain spices can influence TEF. Highly processed foods have a lower TEF than whole foods.

The "Negative Calorie" Myth Debunked

The idea that some low-calorie foods require more energy to digest than they contain is a myth. While digestion does burn calories, the TEF is not high enough to create a net negative calorie effect, even for fibrous foods. Chewing itself burns a negligible amount of calories.

Boosting Your TEF: Practical Tips

While TEF is a small part of your metabolism, you can slightly influence it:

Prioritize lean protein sources.
Choose whole, unprocessed foods.
Include spices like capsaicin in your diet.
Stay physically active.
Remain well-hydrated.

Conclusion

The Thermic Effect of Food (TEF) is a real metabolic process, accounting for around 10% of daily energy expenditure, influenced mainly by macronutrients. While increasing protein and whole food intake can slightly boost TEF, it's a minor factor in weight management. Sustainable results come from a balanced diet, exercise, and healthy habits. For more information, refer to resources like the National Institutes of Health website.

Final Takeaway: TEF is a consistent metabolic process influenced by diet, especially protein and whole foods, but its overall impact on weight management is modest and best combined with other healthy habits.

Frequently Asked Questions

The Thermic Effect of Food (TEF) is the energy your body uses to break down, absorb, transport, and store nutrients from the food you eat. It is one of the three main components of your total daily energy expenditure.

On average, the TEF accounts for about 10% of your total daily calorie intake. So, if you consume 2,000 calories in a day, you'll burn approximately 200 calories simply by digesting that food.

Yes. Protein has the highest thermic effect, meaning your body burns more calories to process it (20-30% of its calories) compared to carbohydrates (5-10%) and fats (0-3%).

No. Despite the popular myth, no food burns more calories to digest than it contains. The thermic effect of food is never high enough to negate the food's total caloric value.

The more processed a food is, the lower its thermic effect. Whole foods require more energy for your body to break down, while processed foods are already partially digested, reducing the energy cost.

Yes, studies have shown that the thermic effect of food, along with the basal metabolic rate, tends to decrease as a person gets older.

While choosing high-TEF foods like protein and whole grains can provide a small metabolic boost, it is a minor factor in your overall energy expenditure. For significant metabolic changes, a combination of diet, exercise, and lifestyle factors is required.