Actually mojoKID, that's not quite true. There is a metobolic advantage to high fat, moderate protein, low carb, so you can't draw exact parallels. This has been experimentally shown in the various studies comparing low fat and low carb diets. People on the low carb diets lose more while comsuming more calories.
Carbs are easily and cheaply (in terms of energy) broken down and turned to glucose. Of the 9 calories per gram of fat, about half is burned converting the whole to usable energy, which is ketones. Protein can be made into glucose in the liver, but this too is only about 50% efficient.
Nyah Levi