Actually it's disputed wether carbs are needed at all. It might be possible to function on fat alone (for energy) https://en.m.wikipedia.org/wiki/Ketosis https:

Actually it's disputed wether carbs are needed at all. It might be possible to function on fat alone (for energy) https://en.m.wikipedia.org/wiki/Ketosis https://en.m.wikipedia.org/wiki/Ketosis