Ketosis is our natural metabolic state, it is a state in which humans utilize ketones/fat for energy. Ketones produce more ATP per molecule and are the preferred substrate throughout the body. They also cause zero inflammation unlike dietary sugar and readily enter all our cells.

It is a biological adaptation process in which ketones supply energy to every single cell in the body except red blood cells. The reason we can assume that ketosis is a biological adaptation is because the brain has already been shown to get 25% of its energy from ketones after 3 days and that jumps up to two-thirds after just 24 days. (Note this is research where obese individuals supposedly didn’t eat anything). There is also evidence clearly showing that fasting for just 3 days supplied the body’s energy requirements with a whopping 30-40% ketones in just 3 days while the body was only utilizing 2-6% ketones eating carbohydrates before.

www.nevereatsugar.com/sources