Quote (ThomasPaine @ Jun 4 2013 08:29am)
I see. Pretty interesting, thanks.
Perhaps it may be due to protein not actually holding 4,1 kcal per g? I've heard of some nutritionist who as of late have argued the necessity to recalculate the caloric value of protein, since it takes more energy to be metabolized and thus the energy resulting from it may be smaller?
Just throwing some thoughts.
Thanks for the study

Quite possible. Also, ketosis itself actually burns more calories than regular glycogen metabolism. The reason for this is because the body has to produce ketones in order to break down body fat and use it as energy.
In totality though, whether or not protein metabolism, and/or fat metabolism are better at burning calories - ketosis in general is more efficient in preserving muscle (actual lean mass, not strength) and also more efficient with regard to burning fat than other diets.
The preservation of muscle is most likely due to the high protein content of the diet, and the increased efficiency is mostly due to the body using fat stores as energy when at rest/fasting.