Chocolate, and lots of it!
You kind of learn to deal with it.. it gets better as time goes on.
You just have to learn to take what they throw at you. It sucks, but if you don't you'd just collapse. Also, chocolate and M&Ms cookies are very useful.
Oh, and purely to help you stay awake: tea/coffee/coke/whatever else contains dangerously high levels of caffeine. Handy for the all-nighters. And the whole of week 8.
Don't get obsessed with chocolate biscuits when you're revising (as i did last summer), if you've a ball to go to - the dress might suddenly not fit (mine still doesn't!)