| Demographic Group: | Students in grades 9–12. |
| Numerator: | Respondents in grades 9–12 with a body mass index (BMI) at or above the sex- and age-specific 95th percentile from CDC Growth Charts: United States.* |
| Denominator: | Respondents in grades 9–12 who answer height and weight questions. |
| Measures of Frequency: | Annual prevalence with 95% confidence interval. |
| Time Period of Case Definition: | Current. |
| Background: | In 2003, a total of 13.5% of students in grades 9–12 were overweight. The proportion of children who are at or above the sex- and age-specific 95th percentile for BMI is increasing. Specifically, during the 1970s and 1988–1994, the prevalence of overweight approximately doubled among children and adolescents aged 6–17 years. |
| Significance: | Physical inactivity and unhealthy eating contribute to obesity and a number of chronic diseases, including some cancers, cardiovascular disease, and diabetes. Being overweight increases the risk of multiple chronic diseases, including heart disease, stroke, hypertension, type 2 diabetes, osteoarthritis, and certain cancers. An appropriate amount, intensity, and duration of regular physical activity and decreased caloric intake might reduce a person’s BMI. |
| Limitations of Indicator: | Respondents tend to overestimate their height and underestimate their weight, leading to underestimation of BMI and of the prevalence of overweight. Overweight cut points of BMI are specific to age and sex, thereby complicating analysis. |
| Data Resources: | Youth Risk Behavior Surveillance System (YRBSS).
http://apps.nccd.cdc.gov/yrbss/ |
| Limitations of Data Resources: | As with all self-reported sample surveys, YRBSS data might be subject to systematic error resulting from noncoverage (e.g., no participation by certain schools), nonresponse (e.g., refusal to participate in the survey or to answer specific questions), or measurement (e.g., social desirability or recall bias). |
| Healthy People 2010 Objectives: | 19-3: Reduce the proportion of children and adolescents who are overweight or obese. (19-3b is specific for adolescents aged 12–19 years.) |
