If they ditch the fries, shakes, desserts, only have 1 burger WITH the bun, and eat a salad/fruit everyday, I would suspect the health of the population they are referring to would improve. In the environment our country is in right now, there is no way they are going to increase spending to provide fresh, healthy food to the poor. It certainly would make great strides in improving our healthcare system. However, I don't believe we have an information problem, i.e., most people know that stuff is unhealthy and choose it anyway. The problem is there is no way the gov is going to advise people to avoid grains considering a large chunk of our tax money goes to subsidizing them, plus I don't think you can feed the population on fruits, veggies, nuts, and animals.
The movie Fat Head goes over a lot of this stuff. I don't agree with the political message of the movie that we should fend for ourselves, considering our gov't puts out shitty information/research wrt nutrition. You can't make an informed decision with bad data.