Childhood obesity

Read a great blog today, posing a question about parents' responsibility when it comes to keeping their children healthy.

http://housewifeinflipflops.blogspot.com/2008/09/childhood-obesity.html

An excerpt:

"If underfeeding your child is considered negligence, would overfeeding
your child be considered the same thing? I don't necessarily mean
forcing food down your kid's throat, I mean more along the lines of
feeding your child lots of empty calories day after day after day and
allowing him or her to eat junk food on a daily basis.

When you see a kid who is obese - not a little bit pudgy, but honestly 20-30 pounds overweight - how do you feel?

This
discussion came up on a forum I read every once in a while. Some people
were saying that allowing your child to become fat is a form of child
abuse, some people were saying that becoming fat is genetic and can't
be blamed on the parent. I don't think either statement is entirely
true, but this subject hits home from me. I was taught AWFUL eating
habits in childhood (Daddy thought eating at restaurants nearly every
night was an acceptable lifestyle) and am still fighting it on a daily
basis as a 28-year-old. I'm busting my hump to make sure the same
doesn't happen to Ace.

What is y'all's opinion in this regard?
Do kids become fat on their own because of the choices they make, or do
parents allow/force it to happen?"