I just don't get the impression that you've paid the least bit attention. Kids aren't markedly heavier than they were fifty years ago. They are not getting markedly less activity than thirty years ago. Kids don't become obese because they eat too many ding-dongs. Obesity is highly heritable. And there is no credible evidence that obesity does not cause the diseases that it is blamed for. Stop the silliness. And stop being a busybody.