This may come as little surprise to parents if they’re honest with themselves: New research indicates 90 percent of children aren’t eating according to healthy diet standards. And less than half of boys and one-third of girls are getting their daily recommended exercise.

But here’s the kicker: This situation contributes to children’s risk of heart disease. In response, the American Heart Association has issued new guidelines for pediatricians to improve kids’ future health.

Instances of obesity more than doubled in children and quadrupled in adolescents over the past 30 years.

The study, a joint effort by Harvard Medical School and Boston Children’s Hospital, traced the cardiovascular health of children ages two to 19, a population that experienced heightened growth in obesity beginning in the 1990s. It concluded that the loss of cardiovascular health in childhood is due to excess weight and obesity.

Obesity has more than doubled in children and quadrupled in adolescents in the past 30 years, according to the Centers for Disease Control and Prevention. More than 18 percent of children ages six to 11 are obese; more than 21 percent of adolescents ages 12 to 19 are obese. An additional 15 percent are overweight. Over a third of children have a higher risk of developing heart issues.

More alarming — the rate of severe obesity among children, currently at 6 percent, is rising.

Since diet and exercise are keys to a healthy weight, the task of changing it often falls to parents, the most influential forces in children’s lives. The AHA cites childhood obesity as the No. 1 health concern among parents, surpassing drug abuse and smoking.

Related: How Our Kids Can Beat Obesity

“We have an obesity epidemic, so overweight parents and kids are more the norm than not,” said Dr. Shelley N. Armstrong, a health educator at Walden University in Shreveport, Louisiana.

“To not be in denial requires work for parents. Most work long hours, or even multiple jobs, so it’s hard for them to find the time to prepare healthy meals and involve kids in recreation. Most parents also overestimate how much their kids move and underestimate how much they consume,”  she told LifeZette.

It’s hard for parents to plan — yet that is instrumental to making healthy changes, she said.

The limits on sugar are three small sodas per week. That’s if no other sugary foods are eaten.

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The statistics on kids’ diets are alarming, said registered dietician Rima Kleiner of Greensboro, North Carolina.

“The fact that half to one-third of children are not engaging in an hour of physical activity every day is a real problem,” she said. “However, the statistic that 91 percent of U.S. children have poor diets is a true wake-up call that we as a community — health care and public health professionals, parents, educators — need to address.”

Parents can be taught healthy, inexpensive ways to prepare food — and kids should learn more about food sources, growing gardens, and easy food prep at school or after-school programs, she believes.

[lz_bulleted_list title=”How Physical Activity Helps” source=”http://www.heart.org”]It controls weight|Reduces blood pressure|Raises HDL (good) cholesterol|Reduces risk of diabetes and some cancers|Helps kids gain more self-confidence[/lz_bulleted_list]

The new dietary guidelines include eating or having four to five fruits and vegetables a day; fish at least twice a week; whole grains only; a low sodium intake; no trans fats; low-fat dairy products and milk after age two; and very limited food and drinks made with sugar.

The limits on sugar are three small sodas a week — if no other sugary foods are eaten. Most processed food contains sugar and trans fats.

Parents should never force-feed children, according to the AHA, or push them to eat beyond their sense of satiety.

The new guidelines recommend 60 minutes of physical activity daily for kids. Armstrong says kids follow the activity examples they see.

“Men are more active than women, so it trickles down to kids,” she said. “Girls have weaker physical activity influences at school and lower participation in extracurricular sports. Female role models, moms and teachers, are the most positive influences. If they are active or place value on sport and exercise, the child will be more likely to as well.”

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Apart from formal exercise, movement and activity in class has been increasing, according to Scott Ertl, a school counselor for 18 years in Winston-Salem, North Carolina.

“Many teachers are finally helping kids be more active in school, instead of forcing them to sit still and be quiet,” Ertl told LifeZette. “Kids are active and need to be active learners. It’s healthier for them.”

Starting in the 1980s, students were increasingly taught via lecture-style classroom models, and therefore moved less. This style favors girls — and since more boys are active learners, they have suffered.

“Most adults don’t like sitting still for five to six hours a day, especially teachers, but they expect kids to do it every day,” Ertl said.

Ertl increasingly sees yoga balls, standing desks, and other movement-encouraging devices in classrooms. Many schools are reinstating activity times and recesses to help kids deal with boredom, fatigue, stress, and anxiety. After seeing active learners get tagged over and over for poor behavior, inattentiveness, and hyperactivity, Ertl invented a portable device students can use at their desk. The Bouncy Band attaches to existing chairs and desks for kids to bounce their feet and stretch their legs.

Related: Kids and Self-Control: This Can Work

One student using the band in class clocked 32,000 steps on a fitness tracker in one day. Within a month, he had reversed failing grades; the times he was cited for disruptions dropped to zero.

Dr. Herbert Insel of Concierge Choice Physicians in New York City, who specializes in preventative cardiology, believes diet and exercise are key but should be valued equally. “Incorporating both in one’s lifestyle is a ticket toward a healthy future,” he noted.

Pat Barone, MCC, is a professional credentialed coach and author of the Own Every Bite! bodycentric re-education program for mindful and intuitive eating, who helps clients heal food addictions.