STATISTICS CONFIRM that kids (actually human beings of any age) who can do AT LEAST one conventional pull-up are almost never obese!
When started young, and if given access to the right experiences, MOST KIDS CAN LEARN TO DO PULL UPS with very little time or effort. And they enjoy the process.
Most kids can SYSTEMATICALLY PREVENT THEMSELVES FROM BECOMING OBESE by learning and maintaining (which requires decent eating and exercise habits) the ability to do at least one pull up.
Here's the Most Recent OPYOW YouTube Video...
Check Out the 90 Second You Tube Video, and...The American Society of Exercise Physiologist's Endorsement
The 10 Minute Workshop Video
Big Bird and Grover Doing Pull Ups