Body Mass Index Estimates for Knox County Schools Children: December 2017 Knox County Health Department Knox County Schools

Transcription

1 Body Mass Index Estimates for Knox County Schools Children: December 2017 Knox County Health Department Knox County Schools

2 INTRODUCTION Childhood obesity continues to put children at risk for poor health outcomes in the future (National Center for Health Statistics, 2016). Left unchecked, obese children may become overweight adults at greater risk for sleep apnea, depression, type 2 diabetes, and other health conditions. This problem could lead to rapid increases in health care costs and loss of productivity in the workplace in the future. The current estimate for childhood obesity in the United States is approximately 17% and affects more than 12 million children (CDC, 2017, April 10). Less than 5 th percentile = underweight 5 th to 84 th percentile = normal weight 85 th to 94 th percentile = overweight 95 th percentile or more = obese Source: CDC, 2016, October 20 Childhood obesity is measured by comparing children s sex, age, height and weight to growth charts originally developed by the Centers for Disease Control and Prevention (CDC) in Children at or above the 95 th percentile are obese, children between the 85 th and 94 th percentile are overweight, and children below the 5 th percentile are underweight (CDC, 2016, October 20). Since 2003, the Knox County Health Department (KCHD) and Knox County Schools (KCS) began measuring the weight and height of students in Knox County Schools using digital scales and stadiometers for BMI measurements. The sampling designs for KCS screenings have varied throughout the years. Since 2014, attempts to screen all Kindergarten, 2 nd, 4 th, 6 th, and 9 h grade students in Knox County Schools have been made. RESULTS In all, 16,410 KCS students in grades Kindergarten, 2 nd, 4 th, 6 th, and 9 th grades from all KCS elementary, middle and high schools were screened between August 17, 2016 and April 27, Responses varied from school to school based on the available screening resources, absenteeism, and other variables. The complete results of the screening are displayed in Table 3 at the end of this report. Both proportion estimates (percentages) and estimated confidence intervals at p <.05 (labeled CI ) are presented in the table to allow for comparisons (Friis and Sellers, 2004). Table 1 compares the results of the number of students screened in the targeted grades with the total enrollment figures for In all, 71.9% of the students in the targeted grades were screened. 2

3 Table 1: Number and percent of KCS students screened for weight and height among total KCS students enrolled by selected grades in the school year # Measured # Enrolled % Measured Kindergarten 3,550 4, % 2nd grade 3,683 4, % 4th grade 3,962 4, % 6th grade 3,327 4, % 9th grade 1,883 4, % Total 16,405 22, % Missing ** 5 *Source: 2015 Personal Communication, John Beckett, September 15, 2017 **Data did not identify the respondent s grades. Figure 1: Percent overweight ( BMI percentiles), obese (95.0 or greater BMI percentile) and both overweight and obese (85.0 or greater percentile) among KCS students: , , , , and * overweight obese overweight and obese Sources: , , , , , Knox County BMI Screenings *Note: Comparisons between the school years should be undertaken with extreme caution due to the varying sample designs As seen in Figure 1, 16.0% of KCS students were obese (95.0 BMI percentile or greater) and 14.2% were overweight (85.0 to 94.9% BMI percentile). More than one out of four KCS students (30.2%) were either overweight or obese (85.0 BMI percentile or greater). There were more obese KCS schoolchildren in the previous school year of with an estimate of 18.0% than in the estimate of 16.0%. 3

4 Table 2: Percent of obese KCS students in Kindergarten, 2 nd, 4 th, 6 th and 9 th grades by age category and Healthy People 2020 objectives for childhood obesity, % Healthy People 2020 % Exceeding % obese Healthy People years 12.3 NWS-10.1: years 14.9 NWS-10.2: 15.7 Target met years 19.2 NWS-10.3: years 16.0 NWS-10.4: Sources: Healthy People 2020, Knox County Schools BMI Screening As seen in Table 2, KCS students aged 6 to 11 years have met the Healthy People 2020 for obesity levels within their age group. Healthy People 2020 is an extensive planning document set forth by the U.S. Department of Health and Human Services. It contains public health goals for communities to meet by the year 2020 to help optimize the health of their citizens. For example, Healthy People 2020 MWS-10.4 specifies there should be no more than 14.5% children between the ages of 2 to 19 years obese. At 16.0%, Knox County has not yet met the objective for children aged 2-19 years; nor has it met the Healthy People 2020 objectives for children aged 2 to 5 years or aged 12 to 19 years. Figure 2: Percent of overweight ( BMI percentile), obese (95.0 or greater BMI percentile) and both overweight and obese (85.0 BMI percentile) among KCS students in Kindergarten, 2 nd, 4 th, 6 th and 9 th grades by gender, Overweight+Obese Overweight Obese Female Male Total Source: Knox County Schools BMI Screening At 16.9% obese, males were more at risk for obesity than females (15.0%) in the school year (Figure 2 and Table 3). When BMI scores for overweight and obese levels were combined, male and female obesity scores were approximately the same with males at 30.4% and females at 29.9%. 4

5 Figure 3: Percent of overweight ( BMI percentile) and obese (85.0 or greater BMI percentile) KCS students by kindergarten, 2 nd, 4 th, 6 th and 9 th grades, th Grade th Grade th Grade nd Grade Kindergarten overweight obese Source: Knox County Schools BMI Screening As seen in Figure 3, among the sampled grades, Kindergarten (20.3%) and second grade students (26.9%) were at less risk for being overweight or obese compared to students in higher grades. Implications for the Community Research indicates that obese children tend to be heavy as they become adults (Ludwig, 2007). As the years progress, obese children may be putting themselves at risk for a variety of weight-related maladies such as orthopedic problems, diabetes, sleep apnea, and possibly shorter life spans. Parents, counselors and others in the community should encourage children to eat high quality foods and play and exercise every day to help them control their weight. Other healthy behaviors such as participating in individual and team sports should be promoted (USDHHS, 2010, January). In addition, the community can work to create more sidewalks, greenways and parks for children to use. All of these approaches could help reduce this problem among children in Knox County. 5

6 References: Centers for Disease Control and Prevention. (2016, October 20). Defining childhood obesity: BMI for children and teens. [Online factsheet]. Division of Nutrition, Physical Activity, and Obesity. Accessed September 26, 2017 at Centers for Disease Control and Prevention. (2017, April 10). Childhood obesity facts. [Online factsheet]. Division of Nutrition, Physical Activity, and Obesity. Accessed September 26, 2017 at Friis, N. Sellers, T. (2004). Epidemiology for public health practice. Joes and Bartlett Publishers, Sudbury, Massachusetts. Ludwig, D. (2007). Childhood obesity-the shape of things to come. New England Journal of Medicine, 357, US Department of Health and Human Services (2010, January). The Surgeon General s vision for a healthy and fit nation. Office of the Surgeon General, Public Health Office, Rockville, MD. US Department of Health and Human Services (2011). Healthy People Office of Disease Prevention and Health. Washington DC. Questions on this report or do you need further information? Please contact J. Mark Prather, Ph.D. Knox County Health Department or mark.prather@knoxcounty.org 6

7 Table 3: Results of the KCS BMI screening by gender, age, type of school, and grade N Underweight Normal Weight Overweight Obese Overweight+Obese % (CI) % (CI) % (CI) % (CI) % (CI) Total 16, ( ) 63.8 ( ) 14.2 ( ) 16.0 ( ) 30.2 ( ) Age Male 8, ( ) 63.3 ( ) 13.5 ( ) 16.9 ( ) 30.4 ( ) Female 7, ( ) 64.3 ( ) 15.0 ( ) 15.0 ( ) 29.9 ( ) Less than 5 years 3 * * * * * 5 years ( ) 67.1 ( ) 10.7 ( ) 12.4 ( ) 23.1 ( ) 6 years 2, ( ) 70.8 ( ) 10.3 ( ) 10.4 ( ) 20.7 ( ) 7 years ( ) 71.1 ( ) 9.0 ( ) 11.6 ( ) 20.6 ( ) 8 years 2, ( ) 66.6 ( ) 12.4 ( ) 15.3 ( ) 27.7 ( ) 9 years 1, ( ) 63.0 ( ) 15.6 ( ) 17.1 ( ) 32.8 ( ) 10 years 2, ( ) 61.5 ( ) 15.7 ( ) 17.9 ( ) 33.7 ( ) 11 years ( ) 58.0 ( ) 16.9 ( ) 17.7 ( ) 35.5 ( ) 12 years 2, ( ) 57.2 ( ) 17.6 ( ) 19.4 ( ) 37.0 ( ) 13 years 397 * 56.7 ( ) 10.3 ( ) 12.1 ( ) 22.4 ( ) 14 years 226 * 58.4 ( ) 18.1 ( ) 21.2 ( ) 39.4 ( ) 15 years 1, ( ) 62.6 ( ) 15.6 ( ) 18.0 ( ) 33.5 ( ) 16 years 334 * 60.5 ( ) 17.4 ( ) 18.9 ( ) 36.2 ( ) 17 years and older 20 * * * * * Type of School Elementary School 11, ( ) 65.9 ( ) 13.0 ( ) 14.7 ( ) 27.7 ( ) Middle School 3, ( ) 57.0 ( ) 17.5 ( ) 19.4 ( ) 36.9 ( ) High School 1, ( ) 61.8 ( ) 16.1 ( ) 18.6 ( ) 34.6 ( ) Grade Kindergarten 3, ( ) 70.8 ( ) 9.9 ( ) 10.4 ( ) 20.3 ( ) 2nd grade 3, ( ) 67.3 ( ) 12.1 ( ) 14.8 ( ) 26.9 ( ) 4th grade 3, ( ) 61.2 ( ) 16.1 ( ) 17.8 ( ) 33.9 ( ) 6th grade 3, ( ) 56.7 ( ) 17.7 ( ) 19.6 ( ) 37.3 ( ) 9th grade 1, ( ) 61.4 ( ) 16.2 ( ) 18.8 ( ) 35.0 ( ) Missing 5 *Not reported. Unreliable. 7