Overweight and obese toddlers may have a heightened risk of iron deficiency, according to a new study that examined youngsters between the ages of one and three. Researchers found that 20 percent of children in the study who were overweight suffered from iron deficiency, compared to only seven percent of kids who were not overweight. A lack of iron in infancy and early childhood can lead to learning and behavior problems, say researchers, who also say that this is yet another reason why children’s diets should be closely monitored.