For me at least, this is just part of a larger issue: to what extent should morality be legislated?

I still haven't made up my mind on this subject. I know that morality can be legislated (don't steal, don't murder, etc.), but true morality must be internal as well as external, and at what point is the government not supposed to legislate morality? I tend to not like the idea of everyone being able to do whatever makes them happy for the moment, because people are often deceived into sacrificing long-term happiness; yet I also don't think that the government should tell me whether or not to have five Big Macs for lunch because it isn't healthy. So... I'm looking forward to getting some input.