I thought about writing an uber-long post about keto, which is something I talk about constantly here but have yet to really explain. But really, other far more qualified people than I have already written extensively on this subject. So here's one of what will probably be a number of suggested-reading sites.
Keto is NOT a diet. It's an approach to food that makes sense and really works. Read all you can; don't stake your health on my say-so!