Hard to believe we haven't gotten one yet... "The brain needs X amount of carbohydrate to function properly." Benjamin Bikman pointed out in his recent alanine/protein vs. insulin and glucagon talk that there isn't really an established minimum requirement for glucose in the brain--just a minimum glucose/protein attrition. Minimum oxidation isn't the same as a requirement...

My rebuttal is that kids on the ketogenic diet for epilepsy not only need their brains to function--but they fuel substantial brain growth. Babies brain metabolism is like 50 percent of basal, adults is 20 percent--if a small child can do this trick, with my much smaller brain fuel needs, I think I should be able to scrape through.