How you compare to others isn't really relevant as everyone has different budgets, priorities, dietary needs, family size, shop availability etc.
So if you've spend £1000 in the last month and lots of others say the same, it doesn't help you if you can only afford £500.
Look at what you can afford. That's the ultimate limit. If you can't afford to eat, you need to look wider at the overall picture.
Are you getting 'best value'. Using cheaper shops, buying offers, making swaps to cheaper brands/own brands/cheaper meals (eg less meat/fish, cheaper cuts, more pulses and seasonal fruit and vegetables etc).
Do you waste any food? There's always reports about how the average household wastes hundreds of pounds a year on food that they buy and throw away without eating, which I find very hard to believe, but if you are wasting things, can you change how you shop to avoid this?
I don't know how much we spend, because we don't count it, but we waste very little, eat a lot of cheaper meals and mostly buy own brands or on offer, so it's not likely to be above average for our household size.
But we don't do big shops or a regular weekly shop, but go less often and shop around, to get the best combination of value/quality that suits us and we keep a stock of essential non perishables in that are bought when on offer to reduce the spend overall. It's very likely that if you buy the same things from the same supermarket once a week to last the week ahead, you're spending more than you need to, unless you do all your shopping in Aldi or Lidl and you're very careful about what you buy.
Eg I see no point in buying a £1 item every week if you can get 4 for £2.50 every month.