How helpful are free sporting activities for children, in cutting obesity?

Incredibly helpful. Any physical activity is helpful for a healthy lifestyle. Sporting activities aren't for every child but many children find them more fun than other forms of exercise. If you can find free sporting activities then please take advantage of them. What children eat and drink are also critical, but exercise is a huge part of a healthy weight.
Play! Children used to run around and play! the difference between play and exercise is like the difference between sex and artificial insemination. If its fun, you need no encouragement!
Helps. Every bit helps- activity is important, It is also important to learn portion control and to make good choices. Frankfurters, with fries and a large sugar sweetened drink is not a good choice.