While I will admit it is highly debatable and there are too many factors to reach a positive conclusion, I feel consuming more protein and less carbs is important for this reason.
Even if the additional protien is simply additional calories(which it may or may not be), they are very low GI calories. A value of about 30 is typical. Oats, brown rice and yams all have values higher than 90% of protien sources. They typically sit in the 50-70 range. Also eating low GI protein sources lowers the GI of carbs.
And as we all know insulin can be the devil while dieting. So, to me thats why I eat that much protein.
Many will disagree and many will agree. My 2 cents.