It made me nod in agreement when I read that. Anyone who has fasted for a minimum amount of time, at least 10 hours or so can attest that you end up with an in

It made me nod in agreement when I read that. Anyone who has fasted for a minimum amount of time, at least 10 hours or so can attest that you end up with an incredibly clear head, powerful sense of smell and very "switched on" vision system where everything seems sharper and clearer. It's a well known effect and this shows one mechanism behind it.