Nutrition on the road - What, How and Why?

Depends what you mean by 'work'. As an ergogenic aid (ie. legal shit that makes you go faster) recent studies have shown you do not need to stop taking in caffeine beforehand - you still get the benefit even if you're a regular coffee drinker.

I went cold turkey before my first 24hr and maybe the second but didn't for the 3rd and probably wouldn't bother again. Not sure about effect on sleep though - if that's tempered by being regular drinker.

Sorry, yes, meant about long term effects on sleep and using caffeine to keep you awake.