Can we burn calories through digestion? The answer is YES!
Put simply, the process of burning calories for the digestion and metabolism of foods is known as the Thermic Effect of Food. Indeed, our body expends calories in order to digest food and be used for energy.
Of course, you can’t just rely on the calories expended for digestion as a means for weight loss. However, the types of food you eat certainly impacts the amount of calories used, and through this, you can increase the amount of calories you burn per day and influence weight loss.
The three macronutrients discussed here are carbohydrates, fats and proteins. The body expends different percentages of calories to digest each macronutrient:
Carbohydrates: 5-15% of calories used for digestion.
Fats: 0–5% of calories used for digestion.
Protein: 20-35% of calories used for digestion.
To put this into perspective, let’s say you’ve eaten a 700kcal meal consisting of 300kcal carbohydrates, 200kcal fats and 200 kcal proteins. Given this breakdown, your body will expend the following number of calories to break down the food you’ve eaten:
Carbohydrates: 15 – 45 kcal
Fats: 0 – 10 kcal
Protein: 40 – 70 kcal
What do you realize here? Yup – protein requires the greatest number of calories for the body to digest it, followed by carbohydrates and then fats. For carbohydrates, eating higher quality carbohydrates (i.e. low glycemic index carbs) have greater thermogenic properties than low quality carbohydrates (i.e. high glycemic index carbs). Additionally, research has shown that fructose (fruit sugar) has greater thermogenic properties compared to glucose.
Based on the above example, you may think burning 70 kcal for protein digestion alone is quite insignificant. But if you multiply this with 3-4 meals per day (and more depending on the amount of meals and proteins you consume), this can accumulate to a loss of 210 – 280 kcal per day and 1,470 – 1,960 kcal per week!
So, along with describing to you the Thermic Effect of Food- which I find quite interesting as many people don’t realize our body burns calories to digest food – I want to point out that if you are one trying to lose weight, increasing your protein content within each meal is a great strategy to lose extra calories per day. And the best part is… you don’t even have to move!