There are so many thing that can be stated as there are many important health concerns. However, if I had to pick one, I would say that the American diet has to be changed. Let me give you are few reasons for this.
First, the obesity problem is growing in America. This is perhaps the first time in history where people are obese. We simply eat too much. The health risk associated with this are tremendous. Part of the reason why our health costs are so much is because of our diet. One study estimates that we spend $147 Billion as a nation in medical bills associated with obesity. If we break this down to individuals, then on average, obese people have medical costs that are $1429.
Second, associated with the diet problem, there is a salt problem as well. Foods are too salty and this causes a whole slew of other health related issues. High blood pressure is one of them.
Finally, associated with this is the politics of food and food production. The list can go on.