Comparing banning of fast food to the banning of weapons "For health and safety" doesn't really feel like an apples-to-apples kind of comparison. I don't know about you, but I've never heard of someone dying due to a violent drive-by big-macing... I have however seen people harmed due to distracted drivers who were too busy trying to deal with their food to pay attention to actually driving. (Self driving cars and banning of human drivers on public roads really can't come soon enough.)
And there are a lot of people out there who want to establish social policies to make the overly unhealthy food more expensive while making healthier stuff easier to access. However long term self destructive life choices tend to be internal to the person making the choice with limited direct impact on others. Sure, there is a strain on health care services and such, but that in and of itself is an indirect impact on others.