A new study is raising the alarm about the hearts of children across the nation — scientists found that many U.S. children don’t meet the seven basic standards of good heart health, putting them greatly at risk of developing medical complications later on in life.

Those seven basic standards include having a healthy weight to height ratio, often called a body mass index (BMI); getting enough exercise; avoiding smoking; eating a healthy diet; maintaining healthy levels of cholesterol; keeping blood pressure low; and keeping blood sugar levels at healthy levels, according to an American Heart Association statement.

Diet and physical activity were the main culprits for causing children to have poor heart health. About 91 percent of children in the United States don’t have a good diet, primarily because of consuming too much sugary food and drinks. The AHA says that just half of young boys and a third of young girls between the ages of 6 and 11 are meeting the 60 minutes per day threshold of physical activity, and between the ages of 16 and 19 they were even less likely to be getting that much activity.

Even more concerningly, about a third of adolescents in the United States are trying cigarettes.

The study says that children should avoid cigarettes, their BMI should be below the 85th percentile, they should get at least 60 minutes of moderate to vigorous activity daily, they should eat a healthy diet, they should consume fewer than 170 milligrams of cholesterol per deciliter, maintain a blood pressure below the 90th percentile and keep their blood sugar levels below 100 milligrams per deciliter.

“Instead of taking a wait-and-see approach by treating disease later in adulthood, we should help children maintain the standards of ideal cardiovascular health that most children are born with,” Julia Steinberger, M.D., M.S., lead author of the new statement, professor in pediatrics and director of pediatric cardiology at the University of Minnesota in Minneapolis, said in the statement. “As pediatricians, we see a tremendous opportunity to strive towards true cardiovascular health if we think of the factors that maintain health early in life. It’s much harder to turn back the clock.”