Are you wondering about Mark's eating habits? Mark actually calls himself a "vegan before dinnertime" saying
From the time I wake up until dinner I eat only fruits, vegetables, whole grains and legumes. I don’t even eat white bread during the day. And then starting at dinner, I do. I have one meal a day when I do pretty much what I want, which is normally quite indulgent.
Check out the rest of the talk below.