The following is a video by Michelle the Fruit Doctor who goes into the detail of Keto risks that may not show up until it is too late. The key message is that when one follows a keto style diet one eat meat which is just as insulinic as sugar that by limiting carbs you are left in a potentially false sense of security. Michelle explains it so much better than I ever could.
Included towards the end is an instance of someone following keto, working out and sadly dying. Only the autopsy after the event showed severe athersclerosis. Remember this was an avid keto person who otherwise looked and felt very healthy.