From the New World Order With Fries department:

The great thing about having separate federal, state and regional governments is that they can pay attention to regional issues. For instance, if a shipment of food is making people sick, the local government can ban the sale of that product until the issue is resolved. This happens all of the time. Of course, the people in the food industry don't much like it when their profits are inconvenienced by silly little things like public health. What did they do? They lobbied of course. Earlier this month, the U.S. House of Representatives passed the National Uniformity for Food Act (H.R.4167), a bill that would require uniform labeling and standards on foodstuffs around the country. Yeah, because our country is small enough that the climate never changes from region to region and there is no variation in how certain foods react in certain environments. The food industry's reasons for wanting this bill passed is so they don't have to make 50 different labels for their products. The food industry's reason is a load of rotten milk. When pressed, one of their top lobbyists couldn't cite an example of a product that had even two separate labels due to differing state legislation. (USA Today Editorial - Food Navigator Article - H.R. 4167)