It's far worse in the US - Walmart is full of processed food, there are a whole bunch more chain fast food outlets eg. Chik-Fil-A, Sonic, Taco Bell fast food is cheaper and more accessible, far fewer people walk anywhere, kids are driven everywhere so are generally fatter over there. It just takes a little effort. The times I've gone over there I've persuaded my hosts to take me to specialist Asian outlets so I can get my paws on decent Basmati rice, lentils etc. Sadly the kids there are so throughly brought up (pardon the pun) on fast food, that they are less than keen to try anything different/healthy.
One difference I've seen over here, particualrly within my circle of friends, is a little more diversity - kids that are happy with hummous/wholemeal pitta, organic fruit and veg, proper fruit juice.
So my point really is that we are generally better than the US in terms of healthy eating/excercise for our kids.