Just watched it myself and my I agree, very interesting (Especially the transcranial transmission!).
I did feel some anticipation early on that I was about to be informed I should give up the odd morning fry up during his trip to Scotland but was quietly chuffed to find out as long as you exercise regularly your blood fat levels stay low (The missus was giving me knowing looks prior to this shocker).
I agree about HIIT as it is suddenly en vogue, or certainly HIT, a mate of mine was debriefing me on it recently which amused me.
I might try tailoring some shorter bike rides to encompass HIIT and see what effect it has on my best effort distances. It is far to easy to get drawn into best effort all the way and probably explains why I seem to have hit a plateau recently.