Wrong again... You can't increase muscle mass while being in caloric deficit for 16 hours a day. How do I know ??, because I have a lot of experience with fasting including total abstinence from food for up to 3-4 days at a time... I have experimented and done a lot of fasting when I was much younger, I've also spent a lot of time in caloric deficit just to see what effect it would have on my body and mind, but I don't do that anymore. My priority right now as I get older is to preserve as much muscle as possible. I follow an athletic lifestyle, not a monastic lifestyle.