A review, published in Health Psychology, reveals children who do not receive an offer for intervention or who receive only information tend to experience weight gains of over 2 percent. However, children given direct guidance get into better shape -- experiencing an 8 percent to 9 percent reduction in weight.

"Providers make the assumption that providing information leads to changes," lead author Denise Wilfley, of Washington University School of Medicine in St. Louis, said in a statement. "Providing information is a necessary component, but it’s not sufficient."

After looking at 14 studies involving 527 children, the researchers concluded children need interventions that provide guidance that is active and strategies to help them make behavioral changes.

An "active" treatment involved any combination of diet, physical activity or behavioral treatment recommendations. The sessions varied widely from family counseling about diet to child-only physical training.