Is it right for me to say, that Childhood obesity is the parents fault?

I think it's more complicated than that. Certainly if the children are living in a normal, middle cl area, the parents should have better control over what their children eat. But if the kids are unfortunate enough to live in a poor, crime ridden area, it gets a little trickier. For example, in a bad neighborhood, you might not let your child play outside so they stay in, glued to the tube. And, because processed foods are cheaper than fresh, you buy the bad stuff because it's what you can afford. Finally, there are some medical conditions that contribute to overweight and obesity. I would never put anything just on the parents.