There aren’t many studies around about the long term effects of a ketogenic diet. Your unique body chemistry dictates how you’ll respond to eating this way.
If you’re reading this, you’ll probably already know what a ketogenic diet is but I’ll copy here a very simple explanation from Marcelo Campus MD
In essence, it is a diet that causes the body to release ketones into the bloodstream. Most cells prefer to use blood sugar. This comes from carbohydrates, as the body’s main source of energy. In the absence of circulating blood sugar from food, we start breaking down stored fat into molecules called ketone bodies. This process is called ketosis. Once you reach ketosis, most cells will use ketone bodies to generate energy until we start eating carbohydrates again.