This is how I live in Australia. Got a supermarket on the same street so I’ll think about what I want from lunch, and go buy as close to the exact quantities of what I need to make it.
You may not waste food but you probably produce a lot of packaging waste. At least that’s what I saw in UK and France.
The UK especially produces an astonishing amount of grocery packaging trash compared to the US. I probably produce more food waste in US but I compost so don’t feel too bad about it.
In the US, a single grocery trip can result in 10-20 plastic bags. Not sure about the UK, but in most European countries people bring their own tote bags.
Not a whole lot I don’t think. I take a bag with me and grab unwrapped fresh foods. The only packaging is meats which seems fairly unavoidable. Single use bags have been banned here for about 10 years now.
As a result I have close to no food wasted.