There have always been overweight children. Historically, chubby babies and toddlers were more likely to survive infections and contagious diseases, and overweight children and family members were often signs of affluence and financial security in a community. Thus, in some cultures, overweight was a valued body type.
Today, being overweight puts a child at risk of developing chronic diseases such as type II diabetes, hypertension, and high cholesterol levels. Obesity can promote degenerative joint disease, which will result in painful knees, hips, feet, and back, and it can severely limit physical activity. These are health concerns previously seen only in adults, usually in those over age forty. Obesity can be measured using a tool called body mass index (BMI). The BMI of an individual can be derived from tables or calculated using a formula (weight in kilograms divided by height in meters squared). In the year 2000, the U.S. Centers for Disease Control and Prevention (CDC) released updated growth charts incorporating BMI percentiles for children, beginning with children two years of age and extending the curves to age twenty. Using these gender-specific graphs, children, adolescents, and young adults are at risk for overweight at the 85th through 89.9th percentiles and are classified as overweight at the 95th percentile or greater. Using this criteria, children and teens are not labeled "obese"; technically, they are only "at risk of overweight" or "overweight." In much of the scientific literature, however, the terms are used interchangeably.
Nutritionists and researchers have been tracking data that clearly shows an increasing trend of overweight children in the United States. Monitoring the proportion of overweight children was identified as one of the ten leading health indicators in Healthy People 2010. All ethnic, racial, gender, and age groups have shown increases. For example, in the 1963–1970 National Health Examination Survey (NHES), the prevalence of overweight among white six to eleven years old was 5.1 percent and 5.3 percent for African-American girls of the same age. The prevalence of overweight in this same age group doubled for white girls (10.2%) and tripled for African-American girls (16.2%) in the 1988–1991 National Health and Nutrition Examination Survey (NHANES III). Preliminary data from 1999 NHANES suggests that the percentage of overweight children has continued to increase in recent years. It is estimated that 13 percent of children ages six to eleven years and 14 percent of adolescents ages twelve to nineteen years are overweight. This represents a 2-3 percentage point increase from NHANES III.
African-American and Hispanic teens are more likely to be at risk or over-weight than white or Asian adolescents. Combined data from nine large studies (including NHANES II and NHANES III) of 66,772 children between five to seventeen years old indicates that the highest percentage of over-weight exists among Hispanic boys and African-American and Hispanic girls.
According to Dr. Mikael Fogelholm (at the May 2003 European Conference on Obesity), "the prevalence of obesity among adolescents worldwide has increased more rapidly than in middle-age adults." Outside the United States, obesity rates range from 2 percent in some developing countries to as high as 80 percent on remote Pacific Islands. In the United States, one child in four is now classified as overweight or at risk for becoming overweight. It is generally agreed that the longer and more overweight a child is, the more likely it is that the condition will continue into adulthood. Predisposing factors are complex and include a mix of genetic, social, cultural, environmental, and lifestyle factors.
Statistics show that a child with two obese parents has an 80 percent risk of becoming overweight, a child with only one obese parent has a 40 percent risk, and a child with normal weight parents has a 7 percent risk of becoming overweight. Twins who were adopted by different families were found to be more similar in weight to the biological parents than to their adoptive parents. Although the exact cause is still unknown, prenatal factors such as maternal obesity, excess pregnancy weight gain, and diabetes may also predispose a child to becoming overweight.
Other risk factors include meal patterns (e.g., skipping breakfast, meals and snacks eaten outside of the home, infrequent family dinners), unhealthful dietary intake (e.g., high fat intake, low intake of fruit and vegetables, fast-food meals, low fiber intake, high soft-drink intake), psychosocial factors such as acculturation and parenting style, and declining rates of physical activity. Based on data from NHANES II and III, among children twelve to seventeen years of age the prevalence of overweight increases 2 percent for each additional hour of TV viewed daily.
Prevention is the best treatment. Restricting calories can lead to stunted growth, adversely affect bone density, and even lead to eating disorders. Intervention strategies should involve the family and focus on permanent lifestyle changes under the supervision of a primary care physician or a registered dietitian. Parents can begin by limiting dining out to special occasions and by making time to enjoy regular meals at home together as a family. Time involved in sedentary activities such as playing video games or using the computer should be monitored and supervised, and the whole family should be encouraged to participate in thirty to sixty minutes of vigorous activity each day. To be successful, the entire family must be willing and ready to institute the many gradual, permanent changes needed.
Pharmacological and surgical treatments are associated with long-term risks and serious complications, and they constitute, at best, a last resort for severely overweight adolescents. Prolonged weight maintenance is recommended for many overweight children and allows a gradual decline in BMI as the child grows in height. However, if medical complications related to obesity already exist (sleep apnea, hypertension, dyslipidemia and orthopedic problems) weight loss of approximately one pound per month is recommended.
Barlow, S., and Dietz, W. (1998). "Obesity Evaluation and Treatment: Expert Committee Recommendations." Pediatrics 102(3):1–11.
Ebbeling, Cara B.; Pawlak, Dororta B.; and Ludwig, David S. (2002). "Childhood Obesity: Public-Health Crisis, Common Sense Cure." Lancet 360:473–482.
Meerschaert, Carol (2002). "Managing Obesity in Children." Soy Connection 10(4):2. Also available from <http://www.talksoy.com>
The Center for Weight and Health, University of California, Berkley (2001). "Pediatric Overweight: A Review of the Literature." Available from <http://www.cnr.berkeley.edu>
Centers for Disease Control and Prevention. "CDC Growth Charts." Available from <http://www.cdc.gov/growthcharts>
International Association for the Study of Obesity. Available from <http://www.iaso.org>
National Institutes of Health Weight Control Information Network (2002). "Youths' Weight and Eating Patterns Fall Short of Healthy People 2010 Objectives." WIN NOTES Winter 2002/2003. Available from <http://www.niddk.nih.gov/health>