First of all, please note that I have edited your question because we are not allowed to answer multi-part questions. Therefore, I have picked one aspect of your question to address.
In the United States, food is produced and distributed based largely on free market principles. Because of the free market, our food is produced mostly by big "factory farms" that grow food in a very mechanized way. This is done because this is the most economically efficient way to produce food that we know of.
In terms of hierarchy, what is more important is how food is distributed. With the exception of programs such as the food stamps program, our food is distributed based on what we can afford. There is a stunning array of food that is available in American stores and restaurants, but not everyone can afford all of the kinds of food. One of the major problems in the US is that the food most available to poorer people is rather unhealthy, helping to lead to major problems with obesity in our country.