For an university student in the UK, what would be the average cost for weekly usage of food?

Can you cook, and will you have kitchen facilities where you will be living? Are you willing & able to make things from scratch, or have to rely more on convenience foods? Will you brown bag your lunch and/or snacks to take to campus, or eating at campus dining facilities or local restaurants? Will you be going out for pizza or something with friends on weekends?

How you cook - IF you do! - and how you shop (sales-only? price out lowest cost per serving? buy & cook in bulk & freeze?) determine your costs. If you are frugal, cook from scratch, and purchase larger quantities at lower prices, then cook-and-freeze, can cut your food costs 50% or more. You cannot stay healthy on Cup o'Noodles!

numbeo.com lists costs for various grocery & other items, typical restaurant meal costs, etc. Look up the specific city where you'll be going to school, as costs can vary widely, especially for London. Unless you're frugal, a good shopper & meal planner, I suspect you would be hard pressed to manage on only GBP50 or 60 a week. Excluding any meals out.

Depends if you want to live on POT noodles or not like I did. But I would say you could budget for about £50/60 a week. However if in London then possibly £70/80. That's taking into consideration going out for a meal once in a while with your mates.