I remember the advice in Robert Atkins' book being to start with very little carbs (and ketosis) for a few weeks, but then increase carbs until you're no longer

I remember the advice in Robert Atkins' book being to start with very little carbs (and ketosis) for a few weeks, but then increase carbs until you're no longer losing weight. That's how you can find a personal carb limit, at least theoretically.