Dave said on his site that his diet can be used as a lifestyle diet and you can stay on for as long as you like as long as you get that cheat meal in once a week.
This is exactly why I said "do your research"-- Dave doesn't know everything.
Mitch Sitnick from the University of California, Davis; just found some interesting facts about muscle hypertrophy with the High Fat diet. Basically the study shows that the capacity for muscular hypertrophy is reduced on the High Fat diet. You can find this study in the Journal of Physiology--October 2009.
The Journal of Exercise Physiologyonline, October 5, 2009 states that Whey protein does not increase Muscle mass exclusively the way Dave advocates on his site.
The American Journal of Clinical Nutrition also did a study on Omega 3's (which Dave also advocates) that shows an increase in the risk of Type 2 diabetes.
There was another study recently done that showed the Keto diet causes a weaking of the arterial walls over time. Sorry, I don't have the references.
I just like to read, experiment, and then make my own decisions.
Do your research and don't believe everything you hear.
BTW, Dave is an extremely intelligent human being and I love his site. Hopefully you get the point I am trying to make here.
Good luck.