I've noticed this in Canada as well:
The volume of sugar that kids eat today is out of control. For example, "healthy" fruit juices pack an insane amount of calories. Worse, they're not satiating at all -- which means more calories added later.
Just a few days ago, I saw a family, a biking trio -- mom, dad, and a son. It was strange to see a severely overweight boy but normal looking parents. Those unhealthy habits are tough to overcome. Exercise won't cut it. The diet must change. The kid likely gets whatever junk food he wants. The parents have to put the foot down.