T Nation

Feb 1 Nutrition Tip


Protein and TEF

While all macronutrients require metabolic processing for digestion, absorption, and storage or oxidation, the thermic effect of protein is roughly double that of carbohydrates and fat. Therefore, eating protein is actually thermogenic and can lead to a higher metabolic rate. This means greater fat loss when dieting and less fat gain during overfeeding!

I've heard this before and I'm curious as to what the real difference is in measurable means.

Like how many calories do you burn digesting say 6oz of a carb such as sweet potato vs 6oz of chicken?

Is it a matter of 5 cals or more like 50cals?


Too many variables to come up with an exact number.

Why wouldn't twice the thermic effect suffice? Are you trying to figure out the exact metabolic breakdown of your body?--Good luck with that.


I just want to know if it's enough to actually make a significant difference or not.... I'm not necessarily asking for exact numbers.


I'd say twice the thermic effect is a significant difference.


For every 400 calories consumed from protein 100 calories is burned.


lol but twice 5 calories is certainly not enough. Now if it takes say 50cals normally to digest something of about 6oz then twice would be significant.


poor logic.

first of all anyone should know that the bulk of your calories are burned with basic metabolic functions. Digestion being a fairly major one would suggest the number would be higfher than 5. And I'll say again, if one factor causes you to burn off twice the calories as another that then is significant.

Or experiment for a while. Consume the same # calories with no protein and see how it affects you.


Thank you! So I assume that 400 calories consumed from carbs or fat takes 50 calories to burn then....


The numbers, according to research source, vary, but one paper I recently read suggested the following:

The thermic effect of protein is about 20-30% of intake.

The thermic effect of carbs is about 5-10% of intake.

The thermic effect of fat is between 3-5%.

So, eat 300g protein (1200kcal) and it costs 240-360kcal to process.

Eat 300g carbs (1200kcal) and it costs 60-120kcal to process.

Eat 300g fat and it costs 36-60kcal to process.

These are not small differences.


Thank you JB, that's great, just what I was looking for :slightly_smiling: