Protein is not primarily an energy source and normally wouldn't be
recommended as primary fuel because of the nitrogen waste. That being
said extra dietary protein is probably used more for energy on low carb
diets as a source of glucose in order to spare muscle.

I found this on sports nutrition:"What about protein as a fuel source?
     Amino acids from protein breakdown can undergo oxidative metabolism
to be      used to fuel muscle contraction. Although not primary energy
substrates, amino      acids are used as auxiliary fuels during muscular
work. Exercise duration,      carbohydrate content of the diet, and
muscle glycogen levels affect protein      use for fuel. Oxidation of
branched-chain amino acids (leucine, isoleucine,      and valine) within
skeletal muscles is increased during prolonged exercise      and when
muscle glycogen stores are low. Protein may contribute up to 10-15%
  of the energy needs in endurance exercise, particularly when the
athlete is      carbohydrate depleted."

I think it is very important to think of fat as your fuel on a low carb
diet, not protein. Protein can be used; it does burn hotter and less
efficiently, but it's also leaves nitrogen waste -- so always make sure
to drink plenty of water to help the body get rid of the waste. No I
don't think high protein diets are dangerous.

Liz

[log in to unmask] wrote:
> My understanding was that 60% of protein is gluconized.