Depends on the food, if you're clearing land for a new crop (which many countries have done historically and still do today) then it's not sustainable. And if the native crops are simply not as good nutritionally as the new crop then it's better to eat the new crop even at the ecological cost of the native one, e.g. potatoes vs barley in Ireland.
I'm not sure what you're referring to in your second sentence, not sure why picky eaters wouldn't like meat and potatoes or what that has to do with shipping in general, not even the fact that we do indeed have the capacity and will to ship food halfway around the world already today.