The minimum my shopping comes to is around £40 if I'm really nifty with deals and don't have any surplus items like oils, toiletries, washing up products and household products.
Still I get through in a week:
Dozen mackerel fillets
1kg of chicken thighs
800g of fish
800g of steak
500g of pork
16 eggs
3 tubs of cottage cheese
several kilos of veggies (carrots, marrows, broccoli, mange tout and other bits and pieces I can never remember really - lots!

)
3-4 packs of ham
10 food doctor pittas
500g of mixed nuts
2 packs of spinach
I treat myself to some cheese too

2 pints of whole milk
A pack of frankfurters (cheat dirty snack

)
Couple of tins of baked beans
Couple of tines of chopped tomatoes
Half a dozen apples
Half a dozen bananas
Tub of whole earth crunchy peanut butter
A dozen Pollock fish fingers (dirty snack time!

)
Undoubtedly forgotten items though. Not much pasta or rice - but I do eat it on occasion when I'm dying for a huge carb load. Then again I eat ice cream, and lots of naughty things anyway, so it's a little bit of a lie I worry about carbs ALL the time!
So keeping the bills to £40 is often quite tough - hence why it's usually around £60 or so.
I could make it a lot cheaper by bulking out my meals with rice/pasta - but I've got so used to not eating it now that I'd find it hard to do!