A new study demonstrates that banning fast food advertisements from children’s television programs would reduce the number of overweight children and teens by 14 percent. Previous studies have shown that fast food products combined with a sedentary life style may be associated with a greater risk for many health problems, such as heart disease, obesity, diabetes and high blood pressure.

Researchers at the National Bureau of Economic Research say that banning fast food advertising could reduce the number of obese children in the U.S. by as much as 18 percent. For the study, researchers used data of nearly 13,000 children from the 1979 Child-Young Adult National Longitudinal Survey of Youth and the 1997 National Longitudinal Survey of Youth, both issued by the U.S. Department of Labor. They measured the rate of child obesity against the number of hours of fast food restaurants ads viewed in a given week. The study has found one in four ads was for a fast food chain.

The researchers concluded that a ban on these ads would reduce the number of obese young children by 18 percent and the number of obese older children by 14 percent.

Another important idea to keep in mind is the possibility that overweight kids are more likely to watch TV that other kids, as a sedentary life and obesity go hand in hand. Experts say that inactivity in teenagers is mostly caused by the popularity of video games, DVDs and Internet use, by all the types of food that children take from outside and put them on a couch or in front of the TV.

The study is being published this month in the Journal of Law & Economics.

Those who disagree with the results of the study say that the estimates rely on older data, which were gathered in the late 1990s.

Studies have shown that being overweight as a child significantly increases the risk for heart disease in adulthood as early as age 25. Children who are overweight when they are 7 to 13 years old are much more likely to develop heart disease between the ages of 25 and 75, possibly regardless of whether they lose weight when they grow up.

Childhood obesity rates are very high in the U.S. and they did not drop despite efforts to curb unhealthy eating habits and inform people about the potentially life-threatening dangers associated with obesity. According to the Centers for Disease Control and Prevention, about one third of American kids are obese or overweight. Obesity causes a wide range of health problems, such as diabetes, cardiovascular diseases, sleep apnea and osteoarthritis, including an increased risk of cancer.

Parents should think twice before taking their children to a fast food restaurant as it was demonstrated that only a third of a fast food meal (the “healthy” variant, with apple slices, raisins, or yogurt) exceeds the 430-calorie threshold.