DALLAS — More than 80% of U.S. adolescents were rated as having a poor diet, according to new research in the American Heart Association’s journal Circulation.

Such a diet and overall lack of heart-healthy behaviors may increase chances of heart disease as adults, the A.H.A. said.

The 4,673 participants ages 12 to 19 in the study were part of the National Health and Nutrition Surveys and were analyzed for factors such as blood pressure, total cholesterol, body mass index, blood glucose, healthy diet, physical activity and smoking. The teen diets were ranked on levels of fruits and vegetables, fish, whole grains, salt and sugar-sweetened beverages.

The study also found less than 50% of adolescents had five or more acceptable levels of the above factors, less than 1% of boys and girls reached healthy diet levels, 44% of girls and 67% of boys reached ideal physical activity level, 66% of adolescents had ideal B.M.I. levels, and 33% of adolescents had cholesterol levels in the intermediate or poor ranges.

“The far less-than-optimal physical activity levels and dietary intake of current U.S. teenagers is translating into obesity and overweight that in turn is likely influencing worsening rates of high blood pressure, high cholesterol and blood glucose at these young ages,” said Christina M. Shay, study lead author and assistant professor of biostatistics and epidemiology in the College of Public Health at the University of Oklahoma Health Sciences Center.

Yet the study did find the majority of teenagers had never smoked a cigarette or didn’t try to smoke one within 30 days of two interviews during the five-year study.

“The status of heart health during childhood has been shown to be a strong predictor of heart health in adulthood,” Ms. Shay said. “Members of the medical and scientific community, parents, teachers and legislators all need to focus their efforts on the prevention and improvement of all aspects of cardiovascular health – particularly optimal physical activity levels and diet — as early in life as possible, beginning at birth.”