While a ketogenic diet can put you into a state of nutritional ketosis in a matter of days, it can take weeks to months to become fully keto adapted.

Some Clues to Its Complexity

Human metabolism has evolved to be remarkably flexible in its ability to use a variety of dietary energy substrates. From a cultural history perspective, humans have demonstrated the ability to subsist for generations on up to 80% of dietary energy as carbohydrates at one end of the macronutrient spectrum to over 80% as fat (a ketogenic diet) at the other end. Given this wide range of dietary options, what is the optimum nutrient mix for humans? Is one end of this spectrum better than the other? Or is it best to be somewhere in the middle? If adopting one end of the spectrum, how long does human metabolism take to optimize its use of the dominant fuel provided? Surprisingly, the truthful answer to all of these is ‘we really don’t know!’ Yes, we know that a lot of disease symptoms and health indicators get much better soon after someone starts on a ketogenic diet. What we do not yet fully understand are all of the underlying physiological process through which ketosis promotes metabolic healing, and how long that process takes to get the full benefits.

Keto-Adaptation