In one of my readings today I came across this little gem from Rogan Kersh and James Morone in their Politics of Obesity. I will summarize their point.
An assertion or finding does not have to be true to create change. Science about a health issue is important but so is the power of the message and from whence it comes.
The three issues they noted were tobacco, alcohol and sexual expression. Tobacco turns out, really does kill people - but we didn't start moving against it until the US Surgeon General made a big deal about it. Alcohol is not 100% evil, but we had prohibition when the government said it was, and many men feared blindness from being oversexed, when apparently that is not a real consequence. Now the government pays for ED drugs. (that part's from me :))
We have gotten to the point that obesity is associated with disease and the US Surgeon General and others have spoken on the seriousness of this problem and so - expect those policies to start happening.