"Parents are in a really tough position, " says Dr. Elissa Jelalian, a staff psychologist at the Weight Control and Diabetes Research Center who focuses on the development of intervention programs for children.

CNN: Girl loses 65 pounds in fight against childhood obesity

Even if teens have not actually engaged in risky behaviors but merely brag about them online, this can still affect their future behavior, said study co-author Dr. Dimitri Christakis, professor of pediatrics at the University of Washington and director of the Center for Child Health, Behavior and Development at Seattle Children's Hospital.

CNN: Study: Teens on MySpace mention sex, violence

Now scientists - at the University of California, San Francisco, and Cincinnati Children's Hospital Medical Center - believe that body-penetrating light can alter the development of the eye, at least in mice.

BBC: Light in womb 'gives healthy eyes' - in mice

Royal Castle Child Development Center offers an arts-based health curriculum called Eat Sleep Play that is designed to teach children, parents and caregivers how to eat healthy, get the right amount of sleep and lead an active lifestyle.

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