Keto Question: What are the risks of the Ketogenic diet?

One of my friends is in the medical industry, and his article about the Keto diet mentioned something important.

The ketogenic diet is advertised as a weight-loss wonder and a healthy lifestyle choice. But it is actually a medical diet that comes with serious risks.

My question is, if you are on the keto diet, what risks are you aware of, and what are you doing to minimize those risks?