This turns out to be a surprisingly difficult question to answer. At a minimum, ketosis is a metabolic state in which you produce and metabolize ketone bodies for energy. Some sources consider it to be an abnormal state. Some sources will tell you that it’s a state in which MOST of your energy comes from ketones. Here, we’ll consider ketosis to simply mean that you are producing ketones to meet some of your energy demand that would “normally” be supplied by glucose.