People in the UK go the supermarket more often than people in the U.S.
How does that figure in the figures? Who knows?
Things are changing in the U.K. - but their supermarkets are generally smaller, the shopping carts and shopping baskets they provide are dinky compared to their U.S. counterparts, you'll rarely find "economy-size" packages, and the Britons don't generally have giant SUVs and pick-up trucks into which they can load an 18-week supply of groceries. Further, when they get home, they have only tiny refrigerators, cupboards, and pantries into which to place everything.
Regards,