To say that childhood overweight is due to poor diet and a sedentary lifestyle is too simplistic. We must recognize that in the past, human beings with a genetic propensity for storing body fat, had an evolutionary advantage - they were able to survive times of famine and food shortages. Even though they may have had a predisposition towards obesity, few children and adults actually became fat because so much energy was expended in order to survive. In the last century, we have created a very different environment. It is an environment much more conducive to the genetic expression of obesity.
Few people have to work hard in order to have the basic necessities.
If you are concerned about your families' weight, here are a few suggestions of what you can do. Take a walk with your children. Play frisbee with your children in the yard. Go to the park and run and play with your kids. Turn off the TV and computer and have your kids go outside and play or ride their bikes.