AP

Two new studies out this week support why its important for parents to watch their children's weight, especially in the pre-teen and teen years.

New data finds, although heart disease usually occurs in adults, cardiovascular issues can develop in childhood, especially if youngsters are obese.

Research published in this week's issue of Pediatrics looked at 3,400 adolescents between the ages of 12-19 over a nine-year span. Forty-nine percent of overweight teens and 61 percent of obese teens had one or more cardiovascular risk factors, such as high blood pressure or high cholesterol.

These statistics are particularly alarming when taken into account that people can keep their risk of heart disease low if they can make it to 45 or 50 with a normal body weight, normal blood pressure and cholesterol, and no diabetes.

"What this is saying, unfortunately, is that we're losing the battle early with many kids," Dr. Stephen Daniels, a University of Colorado School of Medicine expert, said.

The study also showed diabetes and pre-diabetes diagnoses increased among the study participants over the nine-year span. All other risk factors remained steady. Experts are uncertain why that was.

The study also found that normal weight isn't a guarantee against heart disease: 37 percent of those in the study who were normal weight had at least one risk factor for heart disease later in life.

A second study looked at 97 adolescents and the relationship between their body fat and heart function. The study found that children who were obese without symptoms of heart disease already had weaker hearts with thicker walls.

Both sets of authors believe these studies show children, especially teens who are overweight, could benefit greatly from weight management to help them avoid cardiovascular problems later in life.