It already is. The Food and Drug Administration exists. There are countless laws that dictate everything from how crops are. grown to how animals are treated to how products are labeled. Moreover, the government purchases enormous quantities of food and distributes it for the military as well as being involved in everything from food stamps to the famed "welfare cheese" strategic food reserve issues.

Now, it's true that the government isn't in control of literally every aspect of food distribution, but they definitely do things to ensure a stable food supply for the country at reasonable prices. (And then there are the billions and billions in farmer subsidies etc.)