My rent was £93 a week, all inclusive, and I spent on average £20 a week on food. Plus my phone bill which was about £8 a week.
Rent - £70 pw (halls)
Nights out £10-£20
Food: £15-£20 although could cut down
If your in london its going to be more expensive tho...so....
I have ~ £130 a week from student finance. £72 for rent a week. £5-10 a week for bills (although these aren't paid each week, that's what they roughly work out at). If I go to the pub then £5-15 depending on how long I stay and if I have food. ~£10 a week on food, but this varies a lot depending on how long it has been since my dad brought me food. Sometimes I might not buy anything and other weeks I might spend £30 on food. Overall I spend £85-100 a week including almost everything.
My rent is £91 a week, and I spend about £20 a week on food. Other than one off costs (joining societies etc.) this is basically all I spend. I have around £140 a week to spend after accommodation.