Why does the CIA want to know if I am eating fast food, and why does the CIA want to know what kind of fast food I am eating? Can I fool the CIA by order fast food from, say Taco Bell, but stiffing TB and going to Burger King instead? Will that be a crime? Who is going to monitor the fast-food eating habits of hundreds of millions of Americans? Will that have to be outsourced to India? Or what?
Perhaps they don't. This is just a beta program. Later on, they'll roll it out to keep track of everywhere everyone goes. They just mentioned fast food to keep people unconcerned.