Maybe economies of scale matter more than I thought:
Determining the amount of energy it takes to bring food from farm to table is difficult, but it looks as though shipping in food from afar is, in some cases, more energy efficient than food produced locally and that the transport energy might not matter as much in comparision to the amount of energy it takes to grow the food in the first place. “And it turns out our own part in the chain is often the most damaging, since when we drive to the supermarket, we might come back with only a few of bags of food in the car boot. Such a trip is far less fuel efficient than the one taken by that same food on its way to the supermarket in a truck packed with the assistance of load-optimisation software, which determines how to stack cargo so that barely an inch of empty space is left in the back of the vehicle.”
(link)
Of course, if you walk or ride your bike, your efficiency goes way up š And this assumes your shopping trip by car is a dedicated trip, not part of a chain of other errands as I try to plan mine.
I still think Chilean grapes or canned beans from China are wasteful, though.