How much do students actually struggle for money these days?

Im about to go off to university, and was wondering just how strapped for cash im actually going to be. will i be spreading one meal out over three days? and will i be buying nothing but the cheapest food every day? my accommodation will be about 84 quid a week, im not sure how much of this is covered by the loan. im just wondering how much spare money i will have after i have dealt with all the necessities