The Daily Mail, which my ex used to consider to be nothing more than a cheap rag, has been very good about reporting on the keto diet. They did a several-part series by Dr. Unwin, a few years ago.
I’d just caution that a ketogenic diet should not be counted on for longevity, except in the sense that metabolic problems can shorten our lifespan, so anything that resolves them is good. But there are natural limits, and I’m not sure that keto helps get us beyond them. On the other hand, I like the notion of “healthspan,” and I fully believe that keto can extend that.