Yeah, though you can get bread a little over £1 it's the more luxury stuff. Most root veg, rice and oats are less than £1/KG and make up the majority of the volume of what we get, we usually spend about £30/week between the 2 of us on food. Most expensive purchase is usually cheddar, which is basically the default cheese here, the one we usually get is £5.42/KG.

Low-end food is apparently way cheaper in the UK than in North America:

https://www.youtube.com/watch?v=fJDg3lMlmBU

There's been inflation since that video went up, so the prices aren't quite that good anymore. There are more recent videos from that channel you can watch to see more current prices though.