Amanda Panas
Case 2 – Epidemiology of Obesity
Foundation: Acquisition of Knowledge and Skills
1. Define epidemiology.
Robert H. Friis defines epidemiology as "concerned with the distribution and determinants of
health and diseases, morbidity, injuries, disability, and mortality in populations. Epidemiologic
studies are applied to the control of health problems in populations." (2010, p. 3) I think that
breaking down different health-related states into specific classifications of morbidity, mortality,
etc. is useful in understanding the scope of the field.
Epidemiology is truly a multidisciplinary field. Mathematics, biostatistics, history, sociology,
demography and geography, behavioral sciences, and law all play a role in the epidemiological
machine. The overlapping nature of epidemiology requires this type of approach to form the broad
perspective of handling a complicated health situation. (Friis 2010) Strong critical thinking skills
are required to determine the type of study necessary to prove or disprove theories and reliance on
other scientific experts is mandatory.
From the Greek word meaning upon the people, epidemiology is commonly referred to as the
foundation of public health. It is used to study the distribution and determinants of health-related
states in human populations. Epidemiology is further defined as the application of this study that
prevents and controls human health issues.
References:
Boyle, M.A., & Holben, H.H. (2010). Community nutrition in action, an entrepreneurial approach.
Belmont, CA: Wadsworth, Cengage learning.
Friis, Robert H., 2010, Epidemiology 101, Jones and Bartlett Publishers.
Merril RM. 2010. Introduction to Epidemiology. Fifth Edition. Jones and Bartlett Publishers,
Massachusetts.
2. What are the U.S. standards for defining overweight and obesity in the pediatric population?
Review the American Academy of Pediatrics (AAP) definition of overweight and obesity in the
pediatric population (see www.aap.org/obesity) and the definition of childhood obesity given
by the Institute of Medicine (IOM). Go to http://iom.edu/CMS/3788/51730.aspx and view
Progress in Preventing Childhood Obesity, then Fact Sheets, then Facts and Figures.
Overweight and obesity are both labels for ranges of weight that are greater than what is
generally considered healthy for a given height. The terms also identify ranges of weight that
have been shown to increase the likelihood of certain diseases and other health problems.
Definitions for Adults:
For adults, overweight and obesity ranges are determined by using weight and height to
calculate a number called the "body mass index" (BMI). BMI is used because, for most people, it
correlates with their amount of body fat.
•An adult who has a BMI between 25 and 29.9 is considered overweight.
•An adult who has a BMI of 30 or higher is considered obese.
See the following table for an example.
Height Weight Range BMI Considered:
5' 9" 124 lbs or less Below 18.5 Underweight
125 lbs to 168 lbs 18.5 to 24.9 Healthy weight
169 lbs to 202 lbs 25.0 to 29.9 Overweight
203 lbs or more 30 or higher Obese
It is important to remember that although BMI correlates with the amount of body fat, BMI does not
directly measure body fat. As a result, some people, such as athletes, may have a BMI that identifies
them as overweight even though they do not have excess body fat.
According to the American Academy of Pediatrics, obesity is assessed in children older than two
years of age using measure of Body Mass Index (BMI), which is calculated from a child's height and
weight (expressed as weight (kg) / [height (m)]squared). BMI is then plotted on CDC BMI-for-age
growth charts to obtain a percentile ranking. It is important to note that in children and
adolescents, BMI is age- and sex-specific. Early Childhood Obesity Prevention Policies by IOM (1)
confirms that childhood obesity: Overweight when between 85th to 95th percentile in CDC growth
charts and Obese when >95th percentile in CDC growth chart. The pediatric definition refers to
children from 2 to 18 years old.
References:
http://www.cdc.gov/obesity/defining.html
American Academy of Pediatrics. About Childhood Obesity.
http://www.aap.org/obesity/about.html. Accessed September 19, 2011.
Center for Disease Control and Prevention (2009). Clinical Growth Charts.
http://www.cdc.gov/growthcharts/clinical_charts.htm Accessed September 19, 2011.
Institute of Medicine. Early Childhood Obesity Prevention Policies. 2011 page 27 ( available at
http://books.nap.edu/openbook.php?record_id=13124&page=27 )
Step 1: Identify the Relevant Information and Uncertainties
1. Go to www.cdc.gov search under “O” for Obesity and Overweight. Review obesity trends.
Next, search for childhood overweight and obesity, and obesity prevalence. Review
overweight trends among children and adolescents from the NHANES surveys that are
listed.
a. High Body Mass Index for Age Among U.S. Children and Adolescents 2003-2006
Results showed that between 2003-2006, 11.3% of children and adolescents aged 219 years of age were at or above the 97th percentile, 16.3% were at or above the
95th percentile and 31.9% were at or above the 85th percentile. Prevalence
estimates of high BMI did show varied differences by age and racial/ethnic group.
No statistically significant change in prevalence of high BMI for age was found
between 2003-2004 and 2005-2006 data although there was a slight decrease in
BMI-for-age estimates at or above the 95th percentile from 17.1% to 15.5% for
children and adolescents aged 2 through 19 years. However, an increase in
prevalence has been seen when compared to NHANES 1994-1998 data.
References:
Ogden CL, Carroll MD, Flegal KM. (2008) High Body Mass Index for Age Among US
Children and Adolescents, 2003-2006. JAMA 220(20) 2401-2405.
b. Prevalence of Overweight Among Children and Adolescents: United States, 20032004
17.1%
c. Click on the fact sheet at www.cdc.gov/nchs/pressroom/06facts/obesity03_04.htm
and review the trend of overweight among Mexican Americans
The prevalence of overweight in Mexican-American and non-Hispanic black girls
was higher than among non-Hispanic white girls. Among boys, the prevalence of
overweight was significantly higher among Mexican Americans than among either
non-Hispanic black or white boys. Similar disparities were observed among adults.
Approximately 30% of non-Hispanic white adults were obese, compared to 45.0% of
non-Hispanic black adults and 36.8% of Mexican American adults fitting into the
“obesity” category per the above link.
Reference:
Center for Disease Control and Prevention. (2009). Obesity is Still a Major Problem.
http://www.cdc.gov/nchs/pressroom/06facts/obesity03_04.htm. Accessed September 27, 2011.
Prevalence of Obesity* Among U.S. Children and Adolescents (Aged 2–19 Years)
Survey Periods
NHANES II
NHANES III
NHANES
NHANES
1976–1980
1988–1994
1999–2002
2003–2006
Ages
5
7.2
10.3
16.3
2 through 5
Ages
6.5
11.3
15.1
16.95
6 through 11
Ages
5
10.5
14.8
17.6
12 through 19
Odgen, C. Prevalence of Obesity Among Children and Adolescents: United States, Trends
1963-1965 Through 2007-2008. CDC. Retrieved September 25, 2011 from
http://www.cdc.gov/nchs/data/hestat/obesity_child_07_08/obesity_child_07_08.htm.
2. What are some of the determinants of obesity in the Hispanic population that may be relevant
to your target population? Use the websites above and other resources relevant to your target
population.
- Material overweight/obesity (may contribute to childhood obesity d/t modeling behavior,
mother not identifying obesity as an issue)
- Food consumption (increased fast food, less home cooking)
- Physical Activity (less in Mexican American Children than Mexican children, more driving)
- Acculturation
Research by Leigh Small, Bernadette Mazurek Melnyk, Debora Anderson Gifford, & Jeffery S. Hampl
highlight parental strictness and personal behavior as affecting children’s eating habits. They also
reported that many parents studied feel that “how a person is raised from childhood” (2009, p.362)
is directly related to obesity prevalence in children. The importance of parental modeling cannot be
minimized when looking at a population that is highly influenced by adult role models and make
important, lasting behavioral choices early in life. It is interesting that most people surveyed do
equate obesity with ill-health. Whether it’s difficulty breathing, diabetes, aching joints, or any
number of other examples, these people knew that it was not good that their children were
overweight. Although parents are not completely to blame for the childhood obesity epidemic, they
do have a powerful influence over their young children’s diet choices.
When comparing cultural differences between the U.S. and Mexico, there are various reasons for an
increase of obesity among Hispanic youths. The commonality of home-cooking in Mexico versus the
habit of fast-food and take-out in the U.S. is a contributing factor. Also, there are fewer automobiles
in Mexico so there is much more physical activity in the form of walking or children in small towns
being allowed to run around outside without the fear of traffic. (Small, et al. 2009)
The desire for the “American Dream” for Mexican immigrants frequently means driving, instead of
walking, to and from destinations, snack foods, television, and video games. (Small, et al, 2009)
Especially for young people who have experienced both cultures, the attraction of these luxuries is
irresistible.
The result is a childhood obesity rate that is increasing among Hispanic Americans. Complicating
these factors further is the need for nutrition education in these communities. Parents’ uncertainty
of how they know if their child was overweight or not is a serious concern and unless they receive
strategies and information relevant to proper diet and exercise, the obesity trend will continue.
One study (Rosas et al, 2011) found that the prevalence of childhood obesity was higher among
children of Mexican descent in the US than those who reside in Mexico. One strong determinant
associated with childhood obesity in this population especially maternal obesity. This could reflect
a genetic connection or speak to the status of the environment. Compared to Mexican-residing
children, Mexican American children in California watched more television, ate more fast food more
frequently and consumed more fruit, as reported by mothers. This alludes to the importance of
determinants such as heredity factors, lifestyle, diet, and hobbies.
A recent study on maternal perception of preschool children's weight among Hispanic WIC
participants in LA found the following (Chaparro et al. 2011): The majority of mothers classified
their overweight or obese child as being the right weight (93.6% and 77.5% of mothers,
respectively). Higher maternal BMI and higher infant birth weight were associated with less
accurate maternal perception of child weight. This might be one of reasons maternal obesity is
associated with childhood obesity. They don't perceive their child to be obese.
References:
Anderson-Gifford, Deborah, Hampl, Jeffrey S., Melnyk, Bernadette Mazurek, Small, Leigh. "Exploring
the Meaning of Excess Child Weight and Health: Shared Viewpoints of Mexican Parents of Preschool
Children." Pediatric Nursing, Nov/Dec2009, Vol. 35 Issue 6, p357-368
Chaparro P, Langellier BA, Kim LP, Whaley SE. 2011. Predictors of Accurate Maternal Perception of
Their Preschool Child's Weight Status Among Hispanic WIC Participants. Obesity (Silver Spring)
(Epub ahead of print).
Rosas LG, Guendelman S, Harley K, Fernald LC, Neufold L, Mejia F, Eskenazi B. (2011). Factors
Associated with Overweight and obesity among Children of Mexican Descent: Results of a
Binational Study. J Immigrant Minority Health, 13, 169-180.
3. What are some of the uncertainties not presented in the data or the case?
With regard to uncertainties in the case scenario, one of the background conditions namely the
working status of either parents in the families is not available. It will be good to know if parents
have the time and the means to prepare meals based on this data. If both parents are working long
hours for a meager salary, then the kids may have to rely on a dollar menu eaten out of home. Also,
this working hours/job status may help planning the next steps of program design and
implementation.
Other uncertainties:
- Parental opinion towards children’s weight
- Prevalence of families receiving food assistance (in order to assess for other nutrition education
opportunities)
- What the dietary intake of this particular population looks like and how it compares to
state/national data
- It would be helpful to collaborate with oral health/dental professionals to investigate BBTD
prevalence by looking at dietary intake, dentist visits, gaps in education
Step 2: Interpret Information
1. Communicate, in a memo to your agency supervisor, that you wish to begin a program on
overweight prevention for preschool-aged Mexican-American children. To support your
program, include a brief report of recent epidemiologic studies that reveal the national
epidemic of obese children and the health risks that may afflict these children, with a special
emphasis on data for your target population.
TO: Supervisor
FROM: Community Nutritionist
DATE: September 24, 2011
SUBJECT: Obesity Prevention Project
Dear Supervisor,
One in three children of low-income families is either obese or overweight before their fifth
birthday. This is a national trend based on the 2009 Pediatric Nutritional Surveillance System (1).
Aside from income level, racial and ethnic disparities have been noted in this trend. MexicanAmerican boys represent the fastest growing rate of childhood obesity and overweight with nearly
doubling of their obesity rate between the period 1988-1994 and 2007-2008(2). Given that our
county has 100% low-income families and 75% of them are Mexican American, these national
trends would very closely reflect the health status of pre-school children in our county. In view of
this, I would like to start an Overweight Prevention Program for pre-school Mexican American
children in our county.
Approximately one-third of these obese children will develop hypertension (3). Obesity among
Mexican-American children is associated with metabolic changes- starting as early as their sixth
birthday- that include hypercholesterolemia, hyperinsulism and impaired fasting glucose (4). 44%
of Hispanic youth with Type 1 Diabetes were found to be overweight or obese (5). Such trends have
led to statistical projections of disease prevalence and the associated healthcare expenditure which
are significant. As a direct result of today’s overweight and obese children, by 2030, the projected
national prevalence of cardiovascular disease among adults is 40% of adult population with an
associated total cost of cardiovascular disease, including direct and indirect costs, projected to
exceed $1 trillion ($818.1 billion +$275.8 billion) [real 2008$] (6). By year 2034, when nearly 44.1
million adult Americans are projected to have either Type 2 Diabetes the associated projected
health care costs is $336 billion a year (7).
After careful review of current literature, I believe that we should explore the feasibility of
implementing an “Overweight Prevention Program” targeted towards pre-school aged Mexican
American children. As you are aware, Mexican-Americans comprise a significant segment of our
community.
In adults, overweight and obesity ranges are determined by using weight and height to calculate a
number called the "body mass index" (BMI). BMI is used because, for most people, it correlates with
their amount of body fat. An adult who has a BMI between 25 and 29.9 is considered overweight
whereas a BMI of 30 or higher is considered obese.
Early Childhood Obesity Prevention Policies established by the Institute of Medicine of the National
Academy of Science defines increased weight in children (ages 2 to 18) as: overweight when the
BMI is between 85th to 95th percentile in CDC growth charts and obese when the BMI is greater
than the 95th percentile in the chart.
Over the past two decades, the prevalence of children who are obese has doubled, while the
number of adolescents who are obese has tripled. According to the National Health and Nutrition
Examination Survey (NHANES) 31.9% of children and adolescents were overweight and 16.3%
were obese. Although overweight has increased for all children and adolescents over time, NHANES
data indicate disparities among racial/ethnic groups.
Non-Hispanic black girls and Mexican American girls are more likely to have high BMI for age than
non-Hispanic white girls. Among boys, Mexican Americans are more likely to have high BMI for age
than non-Hispanic white boys.
When considering the last decade, of all U.S. adolescence aged 2 to 5, the prevalence of obesity has
fluctuated from 10.6%, 13.9%, 11.0% and 10.4%. In the 6 to 11 year age range there was a gradual
increase from 16.3% to 19.6%. And in the 12 to 19 age group there has been a steady climb from
16.7% to 18 1%. However, when Mexican-American boys are considered over the time period, the
12-19 year age group show and increase from 21.9% to 26.8%. Mexican-American girls in the same
age group show an increase in obesity from 14.1% to 17.4%.
One study (Rosas et al, 2011) found that the prevalence of childhood obesity was higher among
children of Mexican descent in the US than those who reside in Mexico. One strong determinant
associated with childhood obesity in this population is the presence of maternal obesity.
Additionally, a recent study (Chaparro et al. 2011) on maternal perception of preschool children's
weight among Hispanic WIC participants in Los Angeles found that the majority of mothers
classified their overweight or obese child as being the right weight (93.6% and 77.5% of mothers,
respectively). Higher maternal BMI and higher infant birth weight were associated with less
accurate maternal perception of child weight.
As is evident, in the United States, there exists a serious trend towards obesity in adults and
children with a greater tendency in the Mexican-American pre-school population. Accordingly, a
program targeted at controlling the Mexican-American pre-school population, which comprises an
significant portion of our population, would serve to deter the development of obesity in
adolescence and adulthood with a concomitant decrease in the development of serious health
disorders such and heart disease, cancer and diabetes.
Prevention can go a long way in reducing such future burdens (disease and economic) both
nationally and locally in our county. Statistical simulation models have shown that the national
healthcare savings would be $58 billion annually if every American reduced their caloric intake by
100 kcal daily (8). A mere 5% reduction in the future prevalence of diabetes and hypertension
through preventive programs could save $24.7 billion in excess spending nationally (9).
In view of these findings, implementing a program to prevent overweight and obesity among the
pre-school Mexican-American children in our county would help decrease future disease burden
and associated economic burden for our county. I request you to arrange a meeting where I can
have a opportunity to propose a plan for such prevention program.
Thanking you,
Sincerely,
Community Nutritionist.
Reference:
1. Center for Disease Control and Prevention.
http://www.cdc.gov/obesity/downloads/PedNSSFactSheet.pdf (site visited 09/24/11)
2. Center for Disease Control and Prevention.
http://www.cdc.gov/nchs/data/hestat/obesity_child_07_08/obesity_child_07_08.htm (site visited
09/24/11)
3. Kavey RE et al. Management of high blood pressure in children and adolescents. Cardiology
Clinics 2010;28(4):597-607
4. Romero JB et al. Subclinical metabolic abnormalities associated with obesity in pre-pubertal
Mexican schoolchildren. Journal of Pediatric Endocrinology and Metabolism 2010;23(6):589-596
5. Lawrence JM et al. Diabetes in Hispanic American youth: prevalence, incidence, demographics,
and clinical characteristics: the SEARCH for Diabetes in Youth Study. Diabetes Care. 2009;32 Suppl
2: S123-32
6. Heidenriech PA et al. Forecasting the Future of Cardiovascular Disease in the United States: A
Policy Statement from the American Heart Association. Circulation.2011; 123:933-944
7. Huang ES et al. Projecting the Future Diabetes Population Size and Related Costs for the U.S.
Diabetes Care. 2009;32(12):2225-2229
8. Dall TM et al, Potential Health Benefits and Medical Cost Savings from Calorie, Sodium, and
Saturated Fat Reductions in the American Diet. American Journal of Health Promotion
2009;23(6):412-422
9. Barbara Ormond et al, Potential National and State Medical Care Savings From Primary Disease
Prevention. American Journal of Public Health. 2011;101(1): 157-164
10. http://www.cdc.gov/obesity/defining.html
Institute of Medicine. Early Childhood Obesity Prevention Policies. 2011 page 27 ( available at
http://books.nap.edu/openbook.php?record_id=13124&page=27 )
11. American Academy of Pediatrics. About Childhood Obesity.
http://www.aap.org/obesity/about.html. Accessed September 19, 2011.
12. Center for Disease Control and Prevention (2009). Clinical Growth Charts.
http://www.cdc.gov/growthcharts/clinical_charts.htm Accessed September 19, 2011.
13. (About Childhood Obesity. American Academy of Pediatrics. Retrieved September 18, 2011,
from http://www.aap.org/obesity/about.html)
14. Rosas LG, Guendelman S, Harley K, Fernald LC, Neufold L, Mejia F, Eskenazi B. (2011). Factors
Associated with Overweight and obesity among Children of Mexican Descent: Results of a
Binational Study. J Immigrant Minority Health, 13, 169-180.
15. Chaparro P, Langellier BA, Kim LP, Whaley SE. 2011. Predictors of Accurate Maternal Perception
of Their Preschool Child's Weight Status Among Hispanic WIC Participants. Obesity (Silver Spring)
(Epub ahead of print).
Step 3: Draw and Implement Conclusions
1. As part of the Nutrition Care Process, identify the most critical nutritional needs of your target
population as a general nutrition diagnosis; write two PES (Problem, Etiology, Signs and
Symptoms) statements, based on the data reviewed and information presented in the case.
PES #1: “Altered energy balance due to high intake of energy-dense, nutrient-poor foods and
additional barriers for physical activity as evidenced by presence of overweight in 30% of
Mexican-American pre-school children.”
PES #2: “Physical Inactivity (NB-2.1) r/t lack of safe environment for physical activity as
evidenced by increased hours spent performing sedentary activities (TV viewing, computer and
video games).”
References:
American Dietetic Association (2008). International Dietetics & Nutrition Terminology (IDNT)
Reference Manual: Standardized Language for the Nutrition Care Process First Edition.
Step 4: Engage in Continuous Improvement
1. 1. As part of the Nutrition Care Process
a. Outline your intervention plan: Set 3 major goals based on your desired outcomes for your
target population. Include intervention strategies that coincide with these goals. Consider
your nutrition diagnosis when setting up your intervention plan. What may be some
limitations in carrying out your intervention strategies?
Goals
1. Increase the number of preschool
age children participating in 60
minutes of physical activity per day.
Strategies
 Investigate State policy in licensing
requirements in childcare/preschool for
physical activity
 Advertising message on: Billboards, local
television or radio ads, and newspaper ads
would help get our message to the public
and begin to redefine present societal norms
 Plan and implement community exercise
programs to include both aerobic and
strength exercises to meet Healthy People
Goals
2. Goal 2: Increase homemade meals
eaten at home to at least 4 times per
week (reduce convenience foods),
with an emphasis on increasing
fruits and vegetables and whole
grains.
3. Contact community officials to
discuss developing safe areas for
children to play (e.g. parks, game
fields, etc.)
Strategies
2020 goals.
 Develop and implement both individual and
group games/activities for children to
complete that consist of moving, jumping,
running (increasing their heart rate).
 Provide exercise education classes targeted
at children and adults to increase knowledge
of the benefits of exercise
 Conduct cooking classes for parents and
children as an activity to be completed
together, encouraging baking and
grilling, instead of frying foods.
 increasing awareness of the
Supplemental Nutrition Assistance
Program (SNAP)
 the foods can be purchased with SNAP
EBT funds should be the feature
ingredients for the cooking classes.
 Contact community and government
officials to determine course of action
and feasibility.
Possible Limitations: Since we are targeting a Mexican-American population, we should also be
aware of cultural barriers in carrying out our program.
The program may need to be performed bilingually (Spanish/English). Also, since we will want to
be collecting data (and follow-up) data on the nutritional knowledge of our group, these
questionnaires (or interviews) need to be translated to Spanish.
Since we will focus on mothers (in addition to their children), some background understanding of
females in Mexican culture will be helpful. Hispanic women can feel uncomfortable asking the
health educator questions if something is unclear (Lobell et al. 1998). Educators should be trained
in cultural understanding, to be aware of certain behaviors.
References:
Lobell M, Bay RC, Rhoads K, Keske B. 1998. Barriers to Cancer Screening in Mexican-American
Women. Mayo Clinic Proceedings 73(4).
Physical activity: How much physical activity do children need? CDC. Retrieved from
http://www.cdc.gov/physicalactivity/everyone/guidelines/children.html on September 20, 2011.
USDA Food and Nutrition Service, Supplemental Nutrition Assistance Program. Eligible Food Items.
http://www.fns.usda.gov/snap/retailers/eligible.htm
U.S. Department of Health and Human Services. (2011). Healthy People 2020 Physical Activity
Objectives.
http://www.healthypeople.gov/2020/topicsobjectives2020/objectiveslist.aspx?topicId=33.
Accessed September 25, 2011.
b. What areas will you monitor and evaluate to note if you are meeting your desired outcomes?
-Weight trends
-Knowledge- quiz food identification, healthy cooking options, plate method
-fitness tests
-Collect data on buying trends in the community markets focusing on selection of healthful
foods versus non-healthful foods.
-Follow-up questionnaires to reassess the population's nutrition knowledge and
understanding of obesity.