It's a lot lower than 130 a day, I think... that number's suspiciously close to the 120 grams of carb a day mainstream nutritionists are always trying to convince us is the minimum daily carbohydrate we need to fuel our brains. According to Jeff Volek, when ketones go above 1.0 millimolar, we can get more than half of our brain's nutrition from ketones. That drops that 120 grams down to 60. In an intense ketotic state, such as a prolonged fast, that number can go as low as 24 grams of glucose a day, according to earlier studies by George Cahill, one of the the granddaddies of ketones as brain fuel research.

Outside of the brain, cells that require glucose metabolism can get it largely through glucose cycling, where energy is provided by glucose through glycolysis, but instead of being ultimately oxidize, the glucose carbon is broken down into pyruvate and lactate to provide energy, and then recycled into glucose through gluconeogenesis and re-stored as glycogen. Energy from fat is used to fuel that process--so while this adds to the total for gluconeogenesis for the day, it doesn't provide any net glucose to the system.

On a personal note--if a ketogenic diet with insufficient protein and fat to produce 130 net grams of glucose a day constitutes a wasting disease, where lean body mass withers away to make up the gap, that doesn't seem to have manifested yet in my case. Of course, at some point, inadequate protein would be consumed to support lean mass at existing levels, I just doubt that it takes enough dietary protein to support net daily glucose oxidation of 130 grams a day to avoid that point. Can I prove it? Don't know. But has anything been done to prove the opposite, that 130 grams of glucose must be available to the metabolism per day to support lean mass (excluding glycogen)? I think the only real answer we have to this question is eat and see what happens.

That isn't to say some people won't do better on a somewhat less ketogenic low-carb diet.

I do disagree on one point with Jimmy--that low carb diets that are less ketogenic, where enough protein to provide the brain to run mostly on glucose are categorically "wrong." Dr. Atkins advocated both approaches, after all. Induction was "benign ketosis," remember that protein produces more glucose than fat does, etc. After induction, for most people, ketosis was optional--as long as a person was losing pounds or inches.


For the metabolically challenged, he advocated the fat fast. Repeated fat fasts for extreme cases. A week of 1000 calories, 90 percent fat--hard to get more ketogenic than that, and still eat anything. A week of induction--something that would throw the non-metabolically challenged people into ketosis. Rinse and repeat. A sort of intermittent fast, with weekly periods instead of daily. Atkins absolutely includes a form of nutritional ketosis, he just didn't advocate it for everybody, all the time.