About 80% of the parents said they would want to be told if their kid was overweight. I wonder how that 80% overlaps with the parents who can't see how fat their kid is.
I'm on a committee that talks (and talks and talks) about childhood obesity, and one of the big things in the discussion is parental involvement. You can't just give fat kids carrots at school instead of cookies and expect them to lose weight, if they go home to pork fat and ice cream. And if parents really can't see what they send off to school every day, maybe the thing to do is to tell them. From time to time, some school measures BMI and sends it home in notes to parents, but maybe the thing to do is say it in starker terms.
Having spent most of my childhood and much of my life well over the recommended weight of the American Heart Association, I sympathize with the kids and parents, but maybe we should just send home a letter saying your kid is too fat, and she's going to die early unless you do something about it.
Yes, there is a large biological component, and some of us have a horrendous time losing weight. But think of it as early intervention, just as with a kid with hearing problems or Downs. Work on it early, so good things build instead of bad.