Our weekly shop is about £35 for the 2 of us. I'm veggie, but we both eat veggie except once a week when DH eats meat. It probably increases to about £45-£50 if we need toiletries or something like dishwasher tablets, but we usually buy these when they're on offer e.g. 3 for £10 toothpaste or shampoo.
Some years ago when we had financial problems, we started shopping from a list and now we only have one wage coming in, are still pretty good at sticking to it. I'm not able to physically manage a full supermarket shop, so DH does the shopping and he's not interested in browsing, especially when he's trying to eat a healthy diet. We very rarely throw food away. I can't stand for long in the kitchen but do most of the cooking, so we eat simple meals and try new things fairly often. We do splurge at the weekend if we feel like it, but it doesn't happen that often.
When my Mum and Step-Dad come to stay our shopping bill goes through the roof because they're 3 meals a day people who eat meat. Even if we eat out a lot, our food bill is easily 3 times higher. We are usually left with unused food, but it gets used up.