[Evgeny]

Learn you a physiology: http://www.fi.edu/learn/brain/carbs.html

I searched this page for "gluconeogenesis" but did not find it. So basically they completely ignore the fact that the body can produce glucose from amino acids, products of fatty acid oxidation etc?

Edit: Also, the brain only needs a certain amount of glucose - somewhere in the 30-60g per day area. And if the blood sugar is low, the brain will have priority uptaking glucose from blood. So yes, it needs glucose, but one does not need to consume half of his calories or more from carbs - a mere 100g per day or even less would probably be enough.

[robchez]

Exactly right.

100g (or about 400 calories) should be the upper limit of your carbohydrate consumption. Your body will run fine on it.