When I'm there, I make a point of looking at the Reduced shelves, for food that's near its sell-by date. There are often bargains to be had, and it's stuff that would otherwise be thrown away, so buying it is good for the environment too - a double win.
But a lot of fresh food still gets thrown out by the supermarkets at the end of each day, and this has got me wondering whether it wouldn't be eco-friendly to buy more frozen. Of course, the electricity represents a carbon cost, but less food gets wasted - along with all the energy that went into growing, processing, transporting and (perhaps) chilling that food.
I only have a fridge-freezer, so buying huge amounts of frozen food isn't an option for me, but as a general rule, is it greener than fresh - supposing you're buying from a big supermarket in the first place? I've no idea how to figure that one out.