Wellllll, I don't know! Moderate calorie, higher-fat, adequate protein, and carbs no higher than ?X? (120, which is a typical Zone number?) hmm. SP doesn't count LC veggies...so it's possible to eat 80 grams on her plan in a day even if you're only moderately active. well heck, but paleo doesn't limit carbs at all! you can have 14 bananas in a day on that (which would likely result in some darned odd digestive results, but would not result in our eliminating that plan from the board listings) Both the Zone and Dr. Berstein's Diabetic Solution have pretty low calorie levels.

Is insulin control the main object? That would allow CAD, the Zone, and probably paleo to fall under the definition, but barely. CAD allows really HC foods--chocolate cake and milk are fine on that plan. Not all plans are ketogenic, so that can't work.

Is the permanent way of eating a requirement? It seems that most of the programs end up in about the same place in maintenance phase (some retain permanent food restrictions, tho, in particular, the elimination of sugar in all forms)
Do healthy fats matter? Dr A seems to care not a bit about that. Neanderthin, SP and PPLP care a whole lot. (and doesn't the specific carb diet?)

I'm trying to figure it out a bit backwards, Nat. Looking at the programs we accept here as "LC," what are the commonalities...can that help us reach a definition?