The problem is really that people are making poor choices. You can blame it on feeling "sad" or "stressed" or whatever. But the fact of the matter is that -you- yourself are picking up not-so-nutritious food and putting it into your mouth. As impossibly hard as it can be for some people to find the willpower, they kinda need to restrain themselves. Let's face it, tasty junk food only tastes good for the few moments it's in your mouth, then it's done and over with. So why not replace those tiny moments of bliss with something healthy and find other avenues of happiness?
I personally fear for the world in its growing state of obesity. Not only am I scared for the individuals who are harmed through this, but wtf, we ("we" as in Americans, Europeans, apparently Australians, w/e) should you know, share, for Christ's sake? :/ We obviously have more than enough to go around, so why not deposit a fair chunk of our food onto less fortunate countries, at the very least.
Oh sorry, but I forgot about the fit people will throw at losing their precious McDonald's and Wendy's. <-< And since people in America especially are so sue-happy (don't bite me, I'm American too), it's no wonder something like that hasn't been done already.