It will not be easy, but does that mean we should do nothing? Its just like more stringency on firearms. It won't be easy to pass but we must do something. Now that insurance coverage is a requirement (or face a penalty), we can further mandate healthy lifestyle choices, and simply implement penalties for not complying. For instance, nicotine tests. They did it while I was in the military. If you passed a nicotine test it saved money on insurance. My hospital has "healthy lives" which rewards individuals for maintaining a healthy lifestyle.
We can further implement more of these practices.
Okay, but what about people who work dangerous jobs? Maybe you don't like the fact that people are overweight or smoke, but everyone forgets that there are actual jobs that prevent an ideal 'healthy' lifestyle by nature. Exposure to carcinogens/pollutants, hard labor, animal work, etc. Those careers are usually just as much of a choice as smoking and being overweight (to an extent, we know there is more science to obesity than just eating).
Also, I suspect you haven't encountered this, but mandating healthy lifestyle choices sounds like such a noble thing until you realize that those struggling with poverty often cannot afford/physically cannot access healthy food. You can feed a family of 5 for cheap with fast food compared to groceries. $10-15, if that. As for access, haven't you ever heard of food deserts? For example, for a very long time (years and years), Detroit did not actually have a grocery store. Party stores, gas stations, sure, but not an actual grocery store. No one can afford to buy/lease a car, take a cab, or take a two hour (one way) bus ride to the nearest store. Families survive on fast food. I always got a little annoyed with people saying 'Well they don't
look hungry/poor because they're all overweight' when no one bothers to consider the fact that some people in this world can only feasibly feed their families McDonalds. You would be penalizing people for being poor. We already do enough of that with our current state of healthcare, education, jobs, etc.
Also, before you bring up the fact that McDonald's has salads, compare the price of a salad to a large fry and you have your answer. Calories/nutritional value aren't all that different between the two, either.
Oh, and the first grocery store that finally hit Detroit after however many years? Whole Foods, a store that middle class families cannot even afford to shop at weekly.