Joe (SparkPeople Fitness Coach)
I think the most important thing is to look at the root of the problem, which in my opinion is that kids, like adults, are suffering from emotional eating. There are a lot of factors involved—family environments that lack healthy communication and support, an abundance of challenges they face, and opportunities like never before—it results in self-induced pressure, causing them to feel overwhelmed.
When these types of things occur, I believe kids look for something to "soothe" these feelings... food is just one thing they turn to. So before even dealing with the food issue itself, something needs to be done to create healthy communication and support. Once this is set up, it's a lot easier to get the message across that healthy nutrition and exercise is going to benefit them, and then it becomes a process where they learn and unlearn a little bit at a time—with the most powerful influence being the parents taking part in the process as well.
Healthy nutrition and exercise doesn't have to be brought up in terms of physical appearance... this is one of the problems adults face now. A healthy lifestyle is attached too much to appearance instead of vitality. There are numerous other ways to get kids attention on this topic, such as the high rate of cancer in society, high levels of stress, etc.
Obviously, there are a lot of mixed messages out there also, so proper education is at the heart of helping kids, and that is why parents involvement is so crucial.