Why did the goverment ration goods for people to buy?

With the government rationing foods, the people are allowed to but more food for less if they didn't have a lot of money or they were poor. 

Upon the fall of rome, europe ceased being influenced by the cultures of the mediterranean coast and was more influenced by germanic tribal confederations that had already taken over vast swathes of roman territory, although the influence of rome on the former empire was very strong in legal