Understanding Obesity in Children and Teens

The body mass index (BMI) is a number calculated on the basis of an individual's height and weight. We use this number to get a general idea of a person's weight status – underweight, normal, overweight, or obese. In children and adolescents, the significance of a given BMI is more dependent on age and sex than in adults. As a result, the Centers for Disease Control and Prevention (CDC) has established specific charts of BMI-for-age for both boys and girls. You can find BMI calculators on several websites, such as nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm or http://www.cdc.gov/nccdphp/dnpa/bmi/index.htm.

Currently the CDC uses the following terminology when referring to excessive weight in children and teenagers, and it uses these two categories:

  • Being overweight means that the BMI lands between the 85th and 95th percentiles for age and sex.
  • Being obese means that the BMI is more than the 95th percentile for age and sex.

Over the past three decades or so, the prevalence of this problem among children and teens has risen dramatically. Altogether, about 13 million young Americans between the ages of 2 and 19 are obese.

The effects of this condition can be serious. For young people, the fallout from excessive weight involves three major types of issues.

In the first place, it can involve a number of immediate and ongoing health risks. These can include insulin resistance and type 2 diabetes, fatty liver disease, orthopedic problems, sleep apnea and gastroesophageal reflux disease (GERD). Another sobering statistic indicates that sixty percent of overweight children between the ages of 5 and 10 already have at least one risk factor for cardiovascular disease, such as an elevation of cholesterol, triglycerides or blood pressure. Twenty-five percent have two or more of these risk factors.

In the second place, overweight teens and kids are likely to struggle with long-term weight problems. The amount of fat in your body reflects both the size and the number of fat cells, and the number of cells increases most dramatically during late childhood and early adolescence. The overweight child gains more of these cells than his lean counterpart and may begin his teen years with as many fat cells as an adult. When weight is lost – and this is the important point – fat cells shrink in size but not in number, and people with more fat cells regain lost fat more quickly. As a result, the overweight child or early teen is more likely to become an overweight adult who has difficulty maintaining any weight loss. Furthermore, those who are able to control their weight later in life are still more likely to develop coronary artery disease and arthritis than adults who were not overweight as children or teens. This is a key reason for dealing thoughtfully and carefully – and as quickly as possible – with a child's weight problem.

Third and last, there are emotional and social risks that go with being overweight. This is especially true for kids, whose culture at school (or down the block) isn't usually characterized by kindness and understanding. When you're young and overweight, every day can be a brutal gauntlet of insults, snubbing and loneliness. This ongoing assault on the heart and spirit may have lifelong consequences, and preventing or limiting them is one of the most important reasons for parents to take an active role in their child's nutritional health.

The answer to your original question, then, is no – it is not "normal" for a pubescent child or teen to be overweight, but it is increasingly common. Based on the facts and statistics outlined above, we think you can see that this is a disturbing state of affairs. The time to do something about it is now.


Resources

Common Medical Questions About Your Kids

Referrals
Body and Soul Ministries

This information has been approved by the Physicians Resource Council of Focus on the Family.


Excerpted from The Complete Guide to Baby and Child Care published by Tyndale House Publishers. Copyright © 1997, 2007, Focus on the Family.