(Image: If I want to eat it, I'll eat it. If I don't, I won't.)
This is complex. First of all, it's obvious that government has no right to even get close to doing this.
Second, what this and other 'healthy lifestyle messages' does, is that it gives the impression that fat/calories are the root of all evil. Not only do we need fat (not saturated/hydrogenated of course), but other ingredients in our food are more harmful for health, eg pesticides or High Fructose Corn Syrup (a common sweetener which contains mercury).
Fast food has been found to be 'as addictive as heroin'. It's more to do with the sugar content, and artificial ingredients, than it is to do with calories per se.
Big Brother is everywhere. I was reading another news article today, and I was reminded by a TV Licensing ad: "Not paid your TV Licence? We already know. Everything is in our database". To hell with their circuit boards and enslavement grid.