How much would it cost you-as a single person, living on your own-to feed yourself for a week?

And i'm talking balanced, with nutritional value. I'm going to go for £15 per week. No booze or luxuries though.

It would take some planning and it would be a bit shit, but with some preperation and a shit load of imagination, could it be done? I suppose fresh veg and fruit can be pricey, and meat, even the frozen stuff at that budget. Maybe i'm way out, what do people think.