For overweight teenagers, it’s likely the extra body fat, not the lack of fitness, that puts them at risk of cardiovascular problems, according to a new report.

Researchers based in the U.S. found that, among a group of nearly 400 14- to 18-year olds, those with a higher percentage of body fat were more likely to have unhealthy lipid levels that raise the risk of Heart disease - meaning that they had high levels of blood fats (triglycerides), too much “bad” LDL cholesterol, and not enough “good” HDL cholesterol.

Moreover, being fat appeared to have more of an influence on these cardiovascular risk factors than being out of shape, suggesting that fatness has a bigger impact on teens’ health than lack of fitness, the authors report in the journal Pediatric Research.

These findings imply that kids need to start getting healthy early in life - something parents can help with, study author Dr. Bernard Gutin of the Medical College of Georgia in Augusta told.

“It is important to assure that kids grow up in an environment that facilitates vigorous exercise and healthy eating as a way of promoting cardiovascular health, starting in childhood,” Gutin said. He added that parents can serve as “role models,” ensuring kids play outside, enroll in sports, and don’t while away too many hours in front of a computer or TV screen.

As part of the study, Gutin and his colleagues measured the percentage body fat, physical fitness, and factors related to cardiovascular risk in 398 teenagers aged 14 to 18.

They found that both percentage body fat and fitness were linked to lipid profiles and triglycerides, but when they removed the influence of body fat, fitness had little effect on cardiovascular risk factors.

Gutin explained that people with high levels of so-called “bad” cholesterol tend to accumulate more cholesterol in the arteries feeding the heart, which could eventually lead to Heart attacks. Alternatively, people with high levels of “good” cholesterol tend to accumulate less cholesterol, and have fewer Heart Attacks.

Children with unfavorable lipid profiles, therefore, are likely at a higher risk of cardiovascular disease, Gutin noted. “We now know that the pathophysiologic processes underlying heart disease begin during childhood, even though the heart attacks usually occur much later in life,” he said.

SOURCE: Pediatric Research, July 2005.