I'd like to extend this post a little further by tying our culture's current food habits with the lessons learned decades ago with smoking.
In a pre-policy era, smoking was entrenched in the culture. Once harms were understood, policy changed, and the ability of companies to actively advertise their products in television/media was pulled. This lead to a cascade effect (set in motion in 1964), which in turn has led us to today, where the current smoking in the united states is at 18.8% in men and 14.8% in women (
http://www.cdc.gov/tobacco/campaign/tips/resources/data/cigarette-smoking-in-united-states.html). This stands in stark contrast to an era right after the first push against tobacco, where smoking was at 42% prevalence (1965).
Now, to bring it back to our food habits, in the USA the prevalence of Obesity in adults is 34.9% (
http://www.cdc.gov/obesity/data/adult.html). At this point in time, we already know the dangers of poor eating habits, but have not made many changes to public policy. Look at any media today and you will find active advertisements of food that could harm people if consumed regularly. I'd like to point out that education on food habits will likely not do much to prevent obesity, like education on smoking doesn't get people to quit. It is my
opinion that policy is the best way to address the endemic obesity crisis of our current age, much like policy was the best solution for smoking in the past.