What's the difference between buying food in the south and buying food in the north?

Buying food in the north is by the catty, while buying food in the south is by the root. The difference between north and south may be related to the climate between north and south. The north is cold and dry, and food is not easy to deteriorate. Moreover, there were not so many vegetables to eat in winter in the north, so there has always been a tradition of hoarding goods. In the south, it is customary to buy only one meal, because the weather is hot and humid, and the food tends to go bad. Although there is a refrigerator now, I still like to buy food every day, otherwise I always feel that the food has not been fresh for a long time the next day.