Percentage of Obese Children

Chart #3: WHO/FAO Conclusions on

Causes of Obesity

Source: Parliamentary Office of Technology (postnote) Sept. 2003

BMI for Children and Teens

Overweight and Obesity (American Academy of Pediatrics)

Childhood Obesity: Parenting Advice

Obesity and Genetics

Working with Your Doctor

Healthy Eating and Physical Activity: Helping Your Child

Children's Need for Physical Activity

Diabetes Statistics in Youth

Clinical Trials

Obesity is very much in the news for two basic reasons: Doctors have become increasingly aware of the serious health problems it can cause, and more and more people are becoming overweight. Children are not immune to this overall trend; the percentage of seriously overweight children and adolescents has never been so high.

The increase in childhood obesity is accompanied by serious health consequences so that diseases that typically afflict adults, such as high blood pressure and atherosclerosis (blockage of the arteries), are now seen in young people as well. Indeed, drastic solutions to obesity, once resorted to only by adults, are now being adopted by teenagers. For example, some insurance companies are financing a very risky procedure called stomach stapling in which the useable portion of the stomach is surgically reduced.

How Is Obesity Measured?

What exactly do pediatricians mean when they say that a child is obese? The most widely used measure of obesity is the body mass index. A child's weight is divided by his or her height squared (See the formula in the chart called The Body Mass Index). The number gives physicians a sense of how heavy a child is for her or his height. A simple chart (a separate one is used for boys and girls) is then used to determine if the BMI is too high. Twenty-five years ago, only 5% of children of any given age had a BMI that fell above the red line on the chart above (the 95 th percentile of a generation ago) and were classified as obese. Now the number is 15%.

Of course, the BMI isn't a foolproof way of determining whether a child is seriously overweight. After all, children do vary in terms of how muscular they are and in bone size. But the great majority of children whose BMI is above the 95 th percentile are carrying a great deal of excess weight. Many have abnormally high blood pressure and high cholesterol and are at risk for serious health problems in the future.

Why Are More Children Obese Today?

In one sense, the reason why more and more children are overweight is very clear. They must be consuming more calories (food) than they can use. The excess calories -- those not consumed by physical activity -- are converted into fat. Why this is so is not quite so clear, but surveys indicate that children are exercising less and engaging more in pastimes like watching television and playing video games. At the same time snack foods are more widely available and come in larger portions than ever before. Have you noticed the change in the size of soft drinks? A report in the Journal of the American Medical Association concluded that the average drink served has increased from 13 to 20 ounces in the last twenty years.

The problem of childhood obesity in children is not limited to the United States -- it is now a problem for traditionally poor countries where recent prosperity has caused people to eat more and exercise less. In Chinese cities the percentage of obese children has increased from 1.5 to 12.6 percent in the last ten years!

Why some young people become obese while others don't is not completely clear. The problem runs in families -- if even one parent is obese the children are much more likely to develop obesity. Behavioral and lifestyle factors probably combine with many of our genes to influence our tendency to become obese. One reason that breast feeding is so highly encouraged is that infants who are breast fed are less likely to become obese. The World Health Organization has recently summarized the scientific data as to the causes of obesity in children (See Chart #3). The best evidence indicates that a decline in physical activity among children is the culprit.

The Consequences of Obesity in Children

Obese adolescents are at increased risk for developing type II diabetes, a disease that normally is not seen until middle age. The patient with this condition does not respond normally to insulin, which circulates in the blood. This causes glucose levels in the blood to soar, greatly increasing the risk of serious heart problems. Other diseases now seen to be much more prevalent among children due to obesity included asthma, specific kinds of liver complications, and obstructive sleep apnea.

The consequences of childhood obesity are not just physical. Obese children or adolescents can be stigmatized by their peer groups. Or their appearance may become an unfair barrier to full participation in sports and social events. The possibly severe effects of obesity on children's self-esteem should not be ignored. Nor should the fact that obese children, at least those over five years of age, are much more likely to become obese adults and therefore be at increased risk for many diseases throughout their lifetimes.

What Should I Do If I Think My Child Is Obese?

If you are worried that your child is obese, it is a good idea to consult with your pediatrician. He or she can be helpful in assessing your child's weight problem, if any, and also can check for any potential complications like high blood pressure or diabetes. If the physician agrees that a problem exists, you can discuss strategies for weight reduction.

Any weight loss should be tailored to your child's unique needs and environment. All weight loss plans will consist of modest changes in lifestyle and eating habits -- they will not contain punishments or penalties for overeating, but will foster and reinforce positive and constructive changes.

In general, you want to encourage physical activity. Plan family activities that involve both exercise and enjoyment: walks in the neighborhood, games in the yard, visits to the park. Provide a safe environment for physical activities -- be they outdoor games around the house, participation in organized sports, swimming lessons, etc. Children imitate their parents, and if you are more active, they will likely be so, too.

It is well-established that children who watch a great deal of television are much more likely to be obese. Limiting television watching to two hours a day or less is a way of indirectly encouraging physical activity and avoiding the constant advertisements for fast food that children are exposed to while viewing.

The other side of the coin is limiting food intake. Crash diets are never recommended. Children's diets are largely a product of habit. They eat not only what they like, but also what is readily available. To encourage healthy eating habits, parents should keep fruits, nuts, and vegetables on hand as snack foods rather than fast foods like potato chips and cookies. Soft drinks should be avoided -- they are loaded with added sugar. The sugars that are added to soft drinks, cakes, and cookies have a tendency to increase our appetite. Remember that only a fairly modest reduction in your child's calorie intake is needed to change her or his weight profile -- after all, children are still growing! Interestingly, families who eat meals together are less at risk for obesity, so make a special effort to eat with your children as often as you can.

About the Author: Mark Geanacopoulos