Protein has a Thermic effect of about 15% wheras carbohydrates are around 10% as studies indicate.
What this represents is the calories burned through digestion. There is not a significant variance to even matter.
Lets say one takes in 300 grams of carbs or 1200 calories. 10 percent burned is going to be 120 calories.
Now lets compare 300 grams of protein or 1200 calories. 180 calories are going to be burned in digestion.
The variance of 60 calories means nothing. Typing on the computer for an hour also burns 60 calories.
Hope this helps you guys.