Childhood Obesity: A Silent, Looming Epidemic Biostatistics Final Project December 2, 2004 Carrie Hess. Mary Kundus. Mary Helen Smith ABSTRACT Background Obesity is an epidemic in the United States plaguing society especially our children. Additionally, an overweight youngster is more likely to grow up to be an overweight/obese adult. XYZ School District proactively measured body mass index (BMI) of all willing students to examine if the national trend extended to the children in their community. Method Each willing student in the XYZ school district was assessed for their height and weight. BMI was calculated and compared to the national average and categorized for normality as outlined by the Centers for Disease Control and Prevention. Researchers examined the data for obesity and overweight trends defined in this study as an occurrence rate of 20% or higher. Results 6.86% of students tested were classified as obese by CDC standards where obese is defined as a BMI of 30.0 or greater. 21.35% of students tested were classified as overweight by the CDC standards where overweight is defined as a BMI of 25.0 or greater. Conclusion There was not an obesity trend in the XYZ school district; however, there was an overweight trend. Age and school attended were significant factors when comparing the body mass indexes. However, gender was not a significant variable.

INTRODUCTION There is an epidemic of childhood obesity looming on the horizon. According to Mokdad, obesity and nutrition are overtaking tobacco as the number one killer of Americans. (6) The Center for Health and Health Care in Schools (CHHCS) reports that the rate of overweight children, ages 6 – 11 years, has more than doubled from the late 1970’s to 2000’s rising from 6.5% to 15.3%. Even more alarming is the increased rate noted among adolescents, ages 12 – 19 years, which tripled from 5.0% to 15.5% during the same time period. In their report, CHHCS noted that gender was not a factor. However, a disparity exists for increased incidence rates among low income families (below 130% of the federal poverty threshold) and for Mexican and African American population. (2) As a consequence, the health of our children is in peril as rates of juvenile diabetes, hypertension, sleep apnea and other diseases increase simultaneously with the rates of obesity. The Healthy People 2010 initiative has set the goal to eliminate health disparities.(5) To achieve this goal, we need to address this growing problem. To understand childhood obesity we need to define obesity, determine what factors contribute to the problem, explore consequences of obesity, and finally illustrate the point by examining a small metropolitan school population. CHILDHOOD OBESITY Obesity Defined Body Mass Index (BMI) is widely accepted as the indicator variable or standard used to define weight. BMI refers to a person’s relative weight for height. BMI can be used to assess overweight and obesity and to measure changes in body weight. It is a very handy measure to use when testing a large sample population. BMI significantly correlates with total body fat. The BMI calculation is: [weight (lbs) ÷ height (in2)] x 704.5. Conversion tables are used for patient understanding. (3) For children and adolescents, a healthy weight is defined as a BMI of 18.6 to 24.9 while overweight is defined as a BMI of 25.0 to 29.9, obese is defined as a BMI of 30.0 to 39.9 and severe obesity is defined as a BMI > 40.0. However, some researchers avoid using the words “obese” and “obesity” for children. Therefore, during research studies, overweight and obese children and adolescents are defined as being at or above the 85th and 95th percentile of BMI but, are only referred to in the politically correct manner as “overweight”. (3, 4) Obesity Contributing Factors With the explosion of video game systems, the internet, and a plethora of other technologies that spring up daily, a large portion of the population has become sedentary. With each passing year, millions of technological advances occur lessening the need for human activity and/or movement. The youth of America is one population

in particular that has adopted these sedentary behaviors and thus is suffering at a more consequential rate. Gone are the days when kids come home from school to play outside, need a shower after gym, or ride a bike to school. Sadly, even when children do want to go outside and play, their parents are faced with growing security issues ranging from fear of abduction to gun slinging hoodlums in the neighborhood. Single parent families and two-working parent families play a major role in the disappearance of the traditional “dinner time.” Because many people perceive they do not have enough “time”, to salvage as much of the remaining evening as possible, they choose to swing into a drive-thru versus preparing a “home-cooked” meal. This phenomenon is not restricted to working mothers and single parent families of America. “Soccer moms” and the working middle class share the perceived time crunch issues that plague their single parent counterparts. Unfortunately, fast food has become a fast fix for a recurring moment in time, dinner which comes every night. Another major contributing factor to childhood obesity is over nutrition. Not only is dining out increasing, but dining out has become synonymous with “biggie sizing”. This has resulted in children consuming not only high calorie “fast foods” but larger portions as well. Parents may also be contributing to the problem by offering high caloric soda or juices and high caloric, low nutrition snacks. Another contributing factor to this multi-faceted problem is the school lunch option. In addition to having a questionably balanced meal offered, schools have snack bars, soda machines and other vending machines that afford students unhealthy alternatives to lunch food; food that is perceived by many of them as less than tasty. For example, when a child is offered creamed corn versus an ice cream sandwich, the choice is clearly the ice cream. Although the lunch programs are continuously getting better, these confounding variables need to be considered. With a troubled economy, every dollar counts. At times, under-funded school districts can only offer sports where the parents are the primary funding source thereby turning away willing and eager students that can’t afford the basketball or track tuition. Moreover, parents rely on their children participating in physical education (phys. ed.) class to get exercise. Unfortunately, phys. ed. class is less of a priority than a proficiency-based subject and therefore, is always the first to be cut from the roster. This unfortunately leaves some students with no other avenues to participate in physical activity. CONSEQUENCES OF OBESITY Signs of obesity in children and adolescents include asthma, Type 2 diabetes, high blood pressure, sleep disturbances, skeletal disorders, and emotional problems. (4) Approximately 50% of children and adolescents who are obese will become obese adults which leads to an increased risk for major health conditions: diabetes and diabetes-related complications, coronary artery disease, high blood pressure, stroke,

gallbladder disease, cancer (endometrial, colon, kidney, gallbladder, and postmenopausal breast cancer), and osteoarthritis.(2) XYZ SCHOOL DISTRICT ILLUSTRATION Demographics XYZ School District is located in ABC Township in Mahoning County, Ohio, a metropolitan area of 250,000 residents. The 2000 United States Census indicates that ABC Township has a median household income of approximately 41,000 dollars and an unemployment rate of 3.8%. Approximately 6.2% of the households are at or below the poverty level with 15.6% of those households run by single Mothers. 45% of the population has a high school or equivalent education with an elementary school enrollment of 49% (716 students) and high school enrollment of 27% (394 students). Data Description Sample size (n) is 1035 of de-identified school-aged students: grades kindergarten (k) through 12th grade. The data set includes: gender, age, height, and weight parameters. An elementary school is defined as grades k-5 and a secondary school is defined as grades 6-12. Descriptive and Inferential Statistics Analysis The question was posed within the XYZ school district to determine if the “obesity epidemic” had extended itself into the children and adolescents of that community. To explore this issue, a convenience sample was collected from the local school district. The heights, weights, age, and gender were collected from all willing participants. In this study, an obesity trend is defined as 20 % of those sampled with a BMI of 30.0 or greater. An overweight trend is defined as 20% of those sampled with a BMI of 25.0 or greater. Hypothesis Tested 1st Ho: there is not an obesity trend in the XYZ school district. Ha: there is not an obesity trend in the XYZ school district. 2nd Ho: there is not an overweight trend in the XYZ school district. Ha: there is an overweight trend in the XYZ school district. 3rd Ho: age is not a significant factor regarding BMI. Ha: age is a significant factor regarding BMI.

4th Ho: gender is not a significant factor regarding BMI. Ha: gender is a significant factor regarding BMI. 5th Ho: the school attended is not a significant factor regarding BMI. Ha: the school attended is a significant factor regarding BMI. Statistical Analysis SPSS Windows (version12.0) was used for the statistical analysis. ANOVA was used to analyze the age significant factor. Independent sample t-tests were used to analyze school attended and gender variables. P-values of < 0.05 were considered to be statistically significant. Decision The 1st and 4th nulls failed to be rejected. The 2nd, 3rd and 5th nulls were rejected. Results 6.86% of students tested were classified as obese by CDC standards where obese is defined as a BMI if 30 or greater. 21.35% of students tested were classified as overweight by the CDC standards where overweight is defined as a BMI of 25 or greater. Biases The following biases were determined during exploration of the data set: • • • •

Overweight children chose not to participate in the study because they felt self-conscious, Many children did not have the proper consent needed to participate in the study, Because a convenience sample was used, the findings cannot be extrapolated to the general public, and Because age was categorized in years, the findings may differ slightly from actual results.

CONCLUSION For XYZ school district there is not an obesity trend. Age and school attended were significant factors when comparing the body mass indexes. Gender is not a significant variable. However, the inferential statistics implies that there is a combined

overweight/obesity trend (reference tables below) for this particular school district. Our data set illustrates a growing trend among our youth and children toward increased incidences of obesity. Research demonstrates that as obesity rates increases chronic disease rates rise. As a result we are able to predict that the health and quality of life for our youth is in jeopardy. “The Institute of Medicine Committee on Prevention of Obesity in Children and Youth has developed a national strategy that recommends specific actions for families, schools, industry, communities, and government. The findings and recommendations are described in a September 2004 Report titled: Preventing Childhood Obesity: Health in the Balance. The report lays out explicit goals and recommendations for preventing obesity and promoting healthy weight in children. It concludes that actions are needed to initiate, support, and sustain societal and lifestyle changes that can reverse the trend among our children and youth. (1) One of the Healthy People 2010 Core Functions calls for an assurance of the overall improvement in the nation’s health and a reduction of health disparities. However, assuring a healthy nation cannot be accomplished by a single action plan, though the efforts of a single governmental agency, or particular sector of the economy. This change will require a collaborative effort among multiple partners in public health, health care community and physicians, schools, and families to reverse the effect of this silent epidemic. A FINAL NOTE: Based on recommendations provided by Dr. Andrew Chang during the December 4, 2004 presentation, a linear regression was conducted with BMI as the dependant variable and gender, age in years, and school attended as the independent variables (see Table 5). Based on this table, the school attended is not significant (p-value of 0.165 > .05) and would result in a failure to reject the 5th null hypothesis.

Figure 1: Obese Statistics

Obese versus Not Obese Students obese not obese obese 71 6.86% obese

964 93.14% not obese

Figure 2: Overweight Statistics Overweight versus Not Overweight Students overweight not overweight 150 14.49% overweight

885 85.51% not

Table 1: AGE ANOVA Body Mass Index

Between Groups

Sum of Squares 6464.135

df 13

Mean Square 497.241 20.703

Within Groups

21158.063

1022

Total

27622.198

1035

F 24.018

Sig. .000

Age is a significant factor when examined regarding BMI. (p-value .000.05)

Unstandardized Coefficients

Mean Difference

Standardized Coefficients t

Beta

Sig.

181.980

.000

-.176

-1.153

.249

.194

1.783

.075

.789

4.431

.000

Details Overweight/Obese Trend as significant (p-value .000 < .05)

Table 5: Linear Regression Independent Variables Unstandardized Coefficients Model 1

(Constant) age in years elementary or secondary Gender

Standardized Coefficients

B 13.976

Std. Error .718

.604

.076

.749 .243

95% Confidence Interv t

Beta

Sig.

19.473

.000

Lower Bound 12.568

.416

7.906

.000

.454

.539

.073

1.391

.165

-.308

.281

.024

.865

.387

-.309

a Dependent Variable: Body Mass Index

REFERENCES 1. Institute of Medicine Report. http://www.iom.edu/report.asp?id=22596 2. Childhood Obesity: What the Research Tells Us. Fact sheet. http://www.healthinschools.org/sh/obesityfacts.asp 3. American Obesity Association. Finally a Cure for Obesity http://www.obesity.org/subs/advocacy/HealthyWeight_2010.shtml 4. American Obesity Association. Obesity in Youth. http://www.obesity.org/subs/fastfacts/obesity_youth.shtml 1) Scutchfield and Keck, Principles of Public Health Practice, 2nd Edition. ThomsonDelmar Learning. 2003 5. Mokdad, Ali H., Actual Causes of Death in the United States, 2000. Copyright c2004, American Medical Association.

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