I dont have a set amount but I do keep it as tight as I can because Im only PT NMW and I get the groceries. Less I spend there, the more "me" money I have
3 adults. I cook for mum and get her cereals, bits for sandwiches etc, she buys the fancy pickles and biscuits she likes ,the chocolates etc that are for her own use and her own personal toletries etc
I semi meal plan, ie I see whats on offer, whats on the supersavers, whats yellow stickered, and plan from there
I cook from scratch for the 3 of us 6 days a week and also ensure everyone has what they need for breakfast and lunches - DH usually takes left overs or HM soup and sandwiches, mum has a sandwich. On the 7th day ( saturday) I just cook for me and DH as he likes to go to the pub and this way Im not having to chivvy him along so I get dinner at a reasonable time for mum, and its the night we have a cheap as chips dinner - omlette, toastie, jacket spud or pasta meal
Some weeks I can get away with around £20 as its just fruit and veg needed, other weeks I will be passing the chicken processing plant so might spend £20 in there getting chicken to last a month. I try to keep it to around £60 a week on average over a year
We eat well, the salad drawer is always full as are the fruit bowls. A bit samey with veggies and I rely a lot on frozen veg. Meat, we eat a lot more chicken and Turkey then we used to, mainly because the processing plant sells it so cheap.
Im kind of fortunate that whilst we dont have the huge range of shops you have in England, our wee town does have lidl, Tesco, Homebargains and Savers all side by side so I can shop in all at no extra transport costs