The Government. If our doctor ever asks those kinds of questions... me, my wife, and my children will be more than happy to tell him or her to STFU. We will use the long form of that acronym, and tell the questioner to enter that into our medical records.
I've said since 1992 the real goal of any government takeover of health care isn't improving quality or cost for you and me. It is a nifty way for the Progressives - The Left / Mainstream Media - to make an end run around our Constitution. The Rights enshrined therein - to do with ourselves as we see fit (or in the case of a bacon double-cheeseburger, see unfit) and limit government intrusion in our lives - have hampered the Progressive agenda for a century.
By putting our health care providers and our health care information under the control of the Federal government, as ObamaCare does, doctors essentially become snitches of the State - gathering the kind of information the Constitution would bar the Federal government from otherwise acquiring without a warrant or reasonable cause.
Information is power, and with access to the kind of information the doctor at the link above wants, the Progressive Movement achieves their Holy Grail - the very thing the Bill of Rights prevents: Unfettered government control over our lives. Armed with data about our personal habits, likes, dislikes, values, and interests, an enlightened, educated Ruling Class can finally regulate society unimpeded. They can organize, systematize, and manage our lives to arrive at that collective nirvana they are sure they can create if they just had enough control.
Under the rubric of "health care", The Left / Mainstream Media have a way to force us to live as they think we should while still giving lip service to the Constitution. They can claim they are not violating, say, the Rights protected under the First or Second Amendment by demanding we tell our doctor how we voted, what websites we visit, what we eat or drink, or what firearms we own; because we will still - on paper, anyway - have the Right to those things as before.
BUT...... if our doctor and/or a government regulatory agency decides we are exercising those Rights in a way they deem as "unhealthy" or "costing the system too much" (owning a gun or eating a steak or watching FoxNews with our kids), well... we may have to pay much more for our health care, or maybe lose it all together. When government-approved health care plans become the only game in town, we won't have much option. Your wife's surgery or your Right to join a Tea Party. Your heart medicine or eating meat. Pick one.
Note: FWIW, the way we keep our kids safe around firearms is my wife and I have let them become familiar with them, taught them how to correctly use them, and let them shoot with us as often as we can. My daughter isn't intimidated by a .357 Magnum because, well, she knows how to use it.