Land of the "free"

How come the government has the authority to control what we put in our own bodies?  Politicians can't tell us what types of foods to eat or aspirins to take or force us not to have a glass of wine daily. Why is it that the government is allowed to infringe on our individual rights and tell us we can't put steroids into our bodies?

The United States is the land of the free  ...How come we are not free to do as we like with our own bodies?  How come the government can control this aspect of our lives?  This will surely open the door for more limitations on individual freedoms.  Before we know it, the government will ban Hostess and McDonalds, because they aren't "healthy" food choices.... where in our Constitution does the government have the right to do this?