This is at it's core the classic government vs. personal responsibility issue.

This is already required in NYC for chains. It's kind of nice to know that the Five Guys burger and fries I'm about to throw down for lunch satisfies all of the calorie and fat limits recommended for the day in just one meal. At the same time, is there a need for government to mandate this?

I think it's a good tool for people who are looking to be a bit smarter about their consumption habits. Most people understand that the food they're eating isn't good, but I think the problem is that few understand just how bad it actually is. High fat/calorie restaurant chains have little incentive to do something like this, so maybe the .gov getting involved is needed.