Yes, they are hard core raw vegans.
I found between plant based and light fasting my energy level is good. One just has to just try it, to find out, how it affects them. I trust in what my body tells me or I will listen to what others tell me. All I know is that when I do it I get great results for energy level.
I also found, from what others have told me, that they get bad results from plant based diet. Many stories about long, mid, and short term problems with the plant diet. Especially the long term diet problems.
I like to follow how I feel and play with it. See what works and does not work. But, Science is there for a reason too. I guess it all depends who or what you trust. But, I recommend following how your body feels first.
If you start getting tired, upset, or just not the same as when you first started your diet when you felt good maybe the affect was more of a fasting feel. I would make sure your levels of energy stay in the right spot because I hear so many times people starting off good then falling off the cliff like they wanted to hold on then finally let go. Just tweak it here and there so you can maintain something that works for you.