Well, if the cases of someone being able to convert energy from the sun to nourish their body and hunger, it's a form of chemical energy for the body. I am not speaking in terms of achieving optimal health, but just cutting down on food spending by not eating solid food I have to buy. Since I've saved money from eating for almost a month, why not celebrate it by spending it on whatever you want? The motive here is not health but monetary.
As for the cutting down on sleep, what about Thomas Edison who has been doing catnaps? He claim that to not sleep, but perhaps getting 1-3 hours of sleep a day. And he was still creative. No one has died from staying awake (or sleeping) for a long period of time. I think I've read somewhere of a boy who have tried to stay up for 4 days straight..and when he went back to sleep, his mind/body still recover.
