Sainsbury’s believes you can but when Alex Renton took up the challenge, he found his household had serious misgivings. He writes: “Most supermarket sales campaigns are about “value”, which means “lower prices”, though those are not the same thing at all. In pursuit of what would seem impossible, greater earnings with ever-lower prices, the big shops have, over the decades, transferred the profits in food from the producer to the retailer: farmers who used to get more than half the price of a pint of milk now get a quarter. We shoppers and eaters, meanwhile, have transmuted the sensible thrift of our ancestors into a bizarre combination of gluttony and meanness. We eat too much, throw away 30 per cent of the food we buy, yet we want it all cheaper than last week. And we’ve got it — we spend around 11 per cent of household income on it: half what we did 30 years ago.