Unless it is due to a medical problem, if your young child is unfit and overweight then you are a bad parent.
There is a little girl in the nursery I work at that is quite overweight...She is just 3 years old and I need help lifting her onto the swing. She can't run with the other children, in fact she gets tired and starts to drag her feet if she has to walk for more than 10 minuets. I am so angry about this!
When a child is that young they are completely reliant on their parents or carers. They eat what you give them to eat, they exercise when you give them the opportunity.
If you give your child more food than they need, if you feed them junk food and park them in front of the telly all the time then you are abusing your child. Why? Because your actions are having a negative effect on your child's body and overall health. It's neglect!