Recent estimates indicate that approximately 17 percent of children and adolescents in the United States are obese (i.e., a Body Mass Index at or above the 95th percentile) (American Medical Association [AMA], 2007), and over 33 percent are either obese or overweight (i.e., a Body Mass Index at or above the 85th percentile (AMA; Centers for Disease Control and Prevention [CDC], 2006; Ogden et al., 2006). Pediatric weight problems affect children of all ages at alarming rates.
Reports suggest that about 26 percent of 2- to 5-year-olds are obese or overweight. Among children ages 6 to 11, about 37 percent are overweight or obese. For adolescents between the ages of 12 and 19, the combined overweight and obese rate is estimated to exceed 34 percent (Ogden et al.). The high prevalence of pediatric obesity parallels the adult obesity epidemic, with over 32 percent of adults being categorized as obese.
Perhaps even more concerning than the current rates of obesity and overweight among children is the significant increase in these conditions over recent years. According to estimates by Ogden et al. (2006), the percentage of children and adolescents who were obese increased by approximately 23 percent between 1999 and 2004, and the percentage of those who were overweight increased more than 19 percent.
During this period, the largest increase in pediatric obesity was among children ages 2 - 5; the rate grew nearly 35 percent. These increases in obesity among young children are especially alarming in light of research suggesting that children who are overweight before age 8 are likely to have more severe obesity as adults (Freedman, Khan, Dietz, Srinivasan & Berenson, 2001).
The recent increases in pediatric obesity rates are part of a larger trend toward escalating weight problems in children over the last 35 years. Data available through the CDC provide a striking depiction of the developing obesity epidemic. Since the early 1970s, obesity rates among children and adolescents of all ages have risen dramatically (CDC, 2006).
Childhood obesity is the most prevalent pediatric nutritional problem in the United States. It occurs in all parts of the country and affects all income, racial, and ethnic groups. The nutrition and physical activity choices that lead to obesity are influenced by many factors, including lack of access to nutritious foods, individual lifestyle choices, food advertising, and a prevailing culture that promotes overeating and sedentary lifestyles. It affects as many as 15% to 30% of grade-school children and adolescents. The percentage of overweight children aged 6 to 11 years has almost quadrupled from 4% in 1970 to 19% in 2004. The prevalence of overweight varies among different ethnic groups. African American, Hispanic/Latino, and American Indian children and adolescents have particularly high overweight rates. Children also are becoming overweight at increasingly young ages. This is of concern because obesity that occurs early in life and persists throughout childhood is more difficult to treat than obesity that develops later in life. Moreover, a child who continues to be obese into adolescence is at increased risk of developing related health problems. A school-aged child who is at risk of being overweight has an increased probability of becoming an obese adolescent and adult. Obese adolescents are unlikely to attain normal adult weight.
National Health and Nutrition Examination Survey (NHANES) data show a continuing rise in overweight status among children and youth. The increase in overweight from NHANES (1988-1994) to NHANES (1999-2000) has been significant. African American and Mexican American children are disproportionately affected by this problem. For example, among 6- to 11-year-olds, 22% of African American children and 22.5% of Mexican American children are classified as overweight compared to 17.7% non-Hispanic white children.
Children and youth with special health care needs share similar risk for overweight conditions. The risk of obesity in US Special Olympics athletes, both in children and adults, is similar to that of the general population. United States Special Olympians are 3.1 times more likely to be obese than non-US participants in the Special Olympics.
Obesity is associated with significant health problems in children and adolescents and is an important early risk factor for much adult morbidity and mortality. Medical problems that are common in obese children and adolescents can affect cardiovascular health (eg, hypercholesterolemia, dyslipidemia, and hypertension), the pulmonary system (eg, asthma and obstructive sleep apnea), the endocrine system (eg, hyperinsulinism, insulin resistance, impaired glucose tolerance, type 2 diabetes mellitus, and menstrual irregularity), the musculoskeletal system (eg, osteoarthritis), and mental health (eg, depression and low self-esteem).
American Academy of Pediatrics
The largest increase was observed among children between the ages of 6 and 11; the overweight rate went from four percent to 18.8 percent—an increase of 370 percent, (CDC). Similar trends were noted among younger children (178% increase among children ages 2 - 5) and adolescents (185% increase among adolescents ages 12 - 19). A recent study by Kim et al. (2006) found that these alarming trends were seen even in infants, with a 73.5 percent increase in overweight infants observed between 1980 and 2001. The sharp rise in obesity rates shows few signs of abating, and some researchers predict that up to half of all children and adolescents in North and South America could be overweight by 2010 (Wang & Lobstein, 2006).
Obesity is a serious health concern for children and adolescents. Data from NHANES surveys (1976–1980 and 2003–2006) show that the prevalence of obesity has increased: for children aged 2–5 years, prevalence increased from 5.0% to 12.4%; for those aged 6–11 years, prevalence increased from 6.5% to 17.0%; and for those aged 12–19 years, prevalence increased from 5.0% to 17.6%.
Healthy People 2010 identified overweight and obesity as 1 of 10 leading health indicators and called for a reduction in the proportion of children and adolescents who are overweight or obese, but the United States has made little progress toward the target goal.
Progress toward reducing the national prevalence of overweight and obesity is monitored using data from the National Health and Nutrition Examination Survey (NHANES). The most recent NHANES data (2003–2006) showed that for children aged 6 –11 years and 12–19 years, the prevalence of overweight was 17.0% and 17.6% respectively. These prevalence figures are more than three times the target prevalence of 5% set in Healthy People 2010.
Prevalence of Obesity Among U.S. Children and Adolescents (Aged 2 –19 Years)
National Health and Nutrition Examination Surveys
Elissa Jelalian, Ph.D.
Warren Alpert Medical School of Brown University
Providence, RI USA