Why a salad costs more than a Big Mac

provides billions of dollars in subsidies, much of which goes to huge agribusinesses producing feed crops, such as corn and soy, which are then fed to animals. By funding these crops, the government supports the production of meat and dairy products—the same products that contribute to our growing rates of obesity and chronic disease. Fruit and vegetable farmers, on the other hand, receive less than 1 percent of government subsidies.
The government also purchases surplus foods like cheese, milk, pork, and beef for distribution to food assistance programs—including school lunches. The government is not required to purchase nutritious foods. 

 Source, and ht
A note on the source, which is the Physicians Committee for Responsible Medicine:

Founded in 1985, PCRM is a nonprofit organization supported by physicians and laypersons who receive Good Medicine each quarter. PCRM programs combine the efforts of medical experts and grassroots individuals.
Leadership
PCRM Board of Directors: Neal D. Barnard, M.D., President; Mark Sklar, M.D., Director; Russell Bunai, M.D., Treasurer and Secretary.