Participants will be judged on overall percentage change, not on pounds lost. Why? When you excercise to lose fat, you will build muscle. So your weight itself may not change a lot but your overall body composition will improve. You will look better and clothes will fit better.
It's not fair to hold on challenge based on just pounds lost.
We will take measurement as well as weight and those who show the most change overall will be those to receive awards, BUT all who participate will be winners.
Separate division for children and adults
Age groups 8 to 14 and 15 and up. 
There are 4 categories to win, not just one.