IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read
Childhood obesity: Complications, prevention strategies, treatment; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to
www.aapa.org and searching for keyword
JAAPA post-tests. All others may complete and submit the post-test online at no charge at
www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.
KEY POINTS
■ BMI has high specificity and is moderately sensitive, so using BMI alone will underestimate obesity in some children. Waist circumference and triceps skinfold determinations have also been used to define obesity, but neither can be used alone to determine whether a child is overweight or obese.
■ Socioeconomic status is one of the most significant epidemiologic factors in childhood obesity. Compared with children of middle class or affluent households, children of households at or below the poverty level have an 83% increased risk of becoming obese.
■ One theory holds that spending more time in sedentary pursuits increases the risk of becoming obese. Physical activity can promote a healthy lifestyle and decrease the risk of obesity among children.
■ One way to open the discussion of overweight or obesity is to have a BMI chart on hand. When the BMI places a child in the overweight or obese category (BMI in the 85th percentile or higher), the clinician can show the child and/or parent the objective information about the specific BMI.
In February 2010, Michelle Obama announced the "Let's Move" initiative. The goal of this comprehensive program is to eliminate childhood obesity.1 Her goal may seem ambitious, but achieving it is necessary. Childhood obesity has become a growing problem among US children.2 Currently, an estimated 16.9% of them between 2 and 19 years old are obese or above the 95th percentile according to the body mass index (BMI)-for-age growth charts; 11.9% of US children in the 2- to 19-year-old age-group are at or above the 97th percentile.3 In addition, the number of overweight and obese children has increased in almost all countries worldwide.4
Genetic factors, lack of physical activity, and increased consumption of fast food are all possible explanations for childhood obesity.5 Research suggests that families are eating out much more today than they did in the late 1970s.5 One study reported that between 1970 and the mid- to late-1990s, the number of meals eaten away from home by children in the United States nearly doubled.5 Not only is there a convenience factor to less healthy food choices, but the cost of healthy foods seems to be increasing.5 The prices of fruits and vegetables increased by 118% between 1985 and 2000, while the prices of foods high in fats and oils increased by 35%.6 These statistics suggest that foods with added sugars and fats may be the only affordable dietary option for those with limited family incomes.6 Eating a diet that is rich in fat and sugar and limited in fruits and vegetables can lead to childhood obesity and subsequently to adverse consequences, such as issues of self-esteem, insulin resistance, and chronic health concerns, including cardiovascular problems.7
Because of this growing epidemic, physician assistants must maintain an awareness of childhood obesity and be able to recognize children who are obese, overweight, or at risk of becoming obese. This article, the first of two in the current issue of JAAPA, focuses on the etiology, pathophysiology, diagnosis, treatment, complications, and prevention of childhood obesity.
DEFINING CHILDHOOD OBESITY
Obesity is a disease in which a person is at increased risk of unfavorable health outcomes as a result of excess body fat.8 Many methods have been utilized to classify a person as overweight or obese. These methods include measuring waist circumference, calculating BMI, and assessing skinfold tests. Various organizations have advocated different methods of classifying childhood obesity. For example, according to the CDC, the best tool for monitoring weight in children is the BMI,9 which is first calculated based on the child's weight and height, then plotted according to age and gender.9,10Table 1 presents the equations used to calculate BMI and the corresponding weight category status by percentiles. The World Health Organization (WHO) does not state a preference for one method over another, noting that measuring obesity is challenging because there is no standard definition worldwide. Thus, WHO has developed several charts and tables for clinicians to use to assess a child's weight status.11 These include weight-for-age, weight-for-height, BMI-for-age, and triceps skinfold-for-age, among others.11 The American Academy of Pediatrics (AAP) uses the same guidelines for BMI-for-age as the CDC to define childhood obesity and states that for children older than 2 years, BMI is an acceptable measure to assess obesity.10
BMI has high specificity and is moderately sensitive, which means that using BMI alone will underestimate obesity in some children.8 Both waist circumference and triceps skinfold determinations have been used in addition to BMI to define obesity. However, neither waist circumference nor skinfold determinations have a set cutoff point, so they cannot be used alone to determine whether a child is overweight or obese.8 While BMI may not be perfect, it is the most acceptable gross screening measure for overweight children.9
PREVALENCE AND EPIDEMIOLOGY
From 1976 to 1980, the prevalence of US children between 2 and 19 years old with a BMI above the 99th percentile was 0.8%.2 In 1999 to 2004, the prevalence of BMI above the 99th percentile for the same age-group was 3.8%, an increase of more than 300%.2 From the 1970s through the 1990s, the number of children classified as either overweight or obese doubled or tripled in many countries.4 North America and Europe exhibit the highest prevalence of overweight children, while areas of Southeast Asia and sub-Saharan Africa have the lowest prevalence.4 As countries have become more industrialized, eg, Brazil, Chile, Mexico, and Egypt, they have seen an increase in overweight school-age children.4
Numerous factors influence the rising trend of obesity, as noted by the CDC and other researchers. Age, race, gender, and socioeconomic status are some of the most significant epidemiologic factors.
Age The highest rate of obesity lies between the ages of 10 and 11 years; 21.89% of children within this age range are classified as obese. In the 12- to 14-year-old age range, 14.43% of children are considered obese. Finally, between the ages of 15 and 17 years, 10.72% of adolescents were found to be obese.12
Ethnicity and socioeconomic status Increased prevalence of obesity is also linked to ethnicity and socioeconomic status.12 One study found a greater than threefold increase in risk of obesity in poor black children compared with wealthy white children.12 Native Americans/American Indians and Alaskan natives were found to have the highest rate of obesity in 2008 (21.2%), with Hispanics ranking second at 18.5%.9 The CDC also found that in 2008, Colorado and Hawaii were the only states where the number of low-income preschool-age children considered to be obese was 10% or less.9 Indian Tribal Organizations were the only groups with rates higher than 20% (Table 2).
Household income and risk of childhood obesity are inversely proportional. As household income increases, the risk of childhood obesity decreases.13 Household income is a major contributing factor to poverty status among households containing multiple children. Compared with children of middle class or affluent households, children of households at or below the poverty level have an increased risk (83%) of becoming obese.12 Neighborhood social capital, an index of parents' perceptions of social support (eg, cohesion, trust, reciprocity) where they live, is also associated with childhood obesity rates. Children residing in neighborhoods with high social capital have a decreased probability of obesity compared with the probability of obesity for children residing in neighborhoods with low social capital.12
Gender In children 12 years and younger, gender discrepancy in the prevalence of childhood obesity is minimal. However, in children 12 to 17 years, gender differences become more apparent. In one study, males 12 years and older were more likely than their female counterparts to become overweight.13 This is believed to be the result of increased concern with body self-image among females in comparison to their male counterparts. Another study found that African American female children and Mexican American male children between 5 and 18 years maintain the highest prevalence of obesity; the reasons for this are unknown.14
CAUSES OF CHILDHOOD OBESITY
Etiologic factors contributing to the prevalence and development of childhood obesity are numerous and varied. Many times, there is more than one contributing cause, compounding the problem.
Activity level Physical activity increases body metabolism, burns calories, improves cardiovascular health, and decreases the amount of body fat that is stored. One theory holds that children who engage in little to no physical activity are at increased risk of becoming obese.12 A sedentary lifestyle reflects greater amounts of time spent in such activities as television viewing, video game playing, and computer use. Having electronic equipment or a television in the bedroom increases sedentary lifestyle habits.15 For example, children who have a television or electronic equipment in the bedroom have higher BMIs than children who do not.15 Additionally, increased television viewing and video game use, specifically for 3 or more hours per day, is positively correlated with increased risk of obesity among children.12,16
Exercise and other physical activity, such as participation in sports, can promote healthy behaviors and decrease the risk of obesity among children. However, obese children are less likely to participate in sports or extracurricular activities at school, thus increasing the risk for remaining at their current body weight.15 Participating in physical activity—for example, sports, dance classes, or other recreational activities—promotes a healthy weight in children.15
Environment Factors in a child's environment that contribute to the rising trend in childhood obesity include but are not limited to parental education level, location of residence, and characteristics of residence. In their 2008 study, Singh and colleagues showed that parental educational level is inversely proportional to childhood obesity.12 Children with parents who have 12 or fewer years of education have a 50% higher risk of obesity than children with college-educated parents. Children residing in urban or metropolitan areas have an increased risk of obesity attributable to decreased space for outdoor activities, higher crime rates, fewer markets selling fresh produce, and increased presence of fast-food establishments.14
Nutrition Food consumption among children and adolescents is a multifaceted topic that includes the types of food consumed, the location of dining, the preparation of the food, and the eating habits of other members of the household. Nutritional status of children and adolescents is often dictated by their household guardian. Children who reside in a household in which the guardian displays unhealthy eating habits and consumes increased amount of fats and oil have a higher risk of becoming obese than children residing in a household surrounded by healthy eating habits.13 A diet consisting of low-fat dairy products, vegetables, fruits, and legumes decreases the probability of becoming obese, whereas a diet composed of increased amounts of fats, oils, soft drinks, and sodium increases the probability of becoming obese.13 Children who eat regular meals at home are less likely to be obese than children whose family frequently dines out at restaurants or fast-food chains.13 Likewise, children who reside in a household in which the guardian prepares meals using prepackaged or canned food items are more likely to become obese than children who reside in a household in which the guardian prepares meals using fresh produce and protein sources.13
Media and marketing Current technological breakthroughs support the increased use of media devices, such as televisions, iPods, video game devices, and interactive portable devices. Because of these electronic advancements, children are being exposed to a constant flow of advertisements—on average, one food advertisement every 5 minutes.17 Food advertisements target younger children because they are impressionable and cannot comprehend the persuasiveness of the message. Such advertisements use toys, cartoon characters, video games, and professional athletes to sell the food, beverage, or candy product.17 Most food advertisements targeted at children campaign for sugary sweet treats, fast food, and other unhealthy alternatives. Each year, $3 billion is spent by the fast-food industry for advertisement and marketing campaigns directed toward children.18 This increases the likelihood that children will engage in unhealthy eating habits.18
Childhood diseases Childhood obesity can be attributed to endocrine disorders, such as hypothyroidism, pseudohypoparathyroidism, growth hormone deficiency, and Cushing syndrome. Brain injury and CNS disorders resulting from trauma or surgery or following chemotherapy can also lead to obesity in children (Table 3).8
Genetics While genetic abnormalities are extremely rare and should be the last diagnoses considered when evaluating an obese child, they are worth mentioning. Genetic abnormalities that can lead to childhood obesity result from a mutation or polymorphism of numerous receptors, hormones, and enzymes. Signaling molecules, such as leptin, adiponectin, visfatin, and resistin that are present in adipose tissue, can be associated with the development of childhood obesity (Table 3).19
HISTORY AND PHYSICAL EXAMINATION
Begin the evaluation of a child by obtaining a family history. Current recommendations call for children with a family history of dyslipidemia, cardiovascular disease, hypertension, diabetes, and obesity to be screened with a fasting lipid profile when they are between 2 and 10 years of age.20
Information regarding the child's physical activity should be part of the history as well. Determine how much television viewing, computer-related activity, and exercise the child does daily. This information can be recorded and followed using an obesity worksheet provided by The American Academy of Pediatrics (also available in Spanish).
After a thorough history is completed, a physical examination should follow. Weight and height should be recorded for all children at every visit regardless of age and the BMI then calculated.21 The BMI scale can be used for both adults and children; however, children have different result parameters and classifications. Children with a moderately elevated BMI, such as those who fall into the "overweight" category, can be further assessed for obesity using skinfold thickness and waist circumference measurements.22 The age at which to start BMI assessment is a highly debatable subject. Both the CDC and the AAP agree that BMI calculations should begin at age 2 years and continue annually. BMI can then be plotted over time on a growth curve to track any changes over time.
A complete physical examination of the child found to
be overweight or obese includes an assessment of adiposity distribution, syndromic features, and vital signs. A funduscopic examination will detect blurring of the optic disk margins, which could indicate pseudotumor cerebri. Also, examination of the neck to detect thyromegaly as well as assessment of the cardiovascular system, pulmonary system, and abdomen should be completed. Clinicians should examine the skin for signs of acanthosis nigricans, hirsutism, and striae. Finally, the patient's sexual maturity should be assessed to document pubertal status and psychological health.
Children deemed to be at increased risk of metabolic syndrome should begin oral glucose tolerance testing at age 10 years.23 Any child whose BMI is in the 95th percentile or higher requires liver function testing, a fasting glucose determination, and insulin and lipid profiles.23 Comorbidities worthy of consideration in overweight and obese children include hypertension, sleep apnea, and orthopedic problems.23
HAVING THE DISCUSSION ABOUT OBESITY
Discussing obesity with a child, a teenager, or even the parent can be difficult. Children rarely present with an initial chief complaint relating to weight. Many times, the clinician will have to raise the issue of weight with the child or parent during a well-child visit, sports physical examination, or other health assessment. Whether or not the child or, in some cases, the parent should be in the room during the conversation is determined on a case-by-case basis, taking into consideration the relationship between the clinician, child, and the child's family, as well as the child's age and emotional maturity.
One way to open the discussion is to have a BMI chart on hand. Copies can be obtained from the CDC Web site. When the BMI places a child in the overweight or obese category (BMI in the 85th percentile or higher), the clinician can show the child and/or parent the objective information about the risks associated with that BMI. Following the BMI evaluation, a discussion of the child's as well as the family's eating habits should begin. Detailed questions regarding meal preparation, snacks, and fast foods are in order. Cultural awareness and ethnic meal preparations should also be taken into consideration when reviewing the eating habits of the child and other family members.
CONCLUSION
Obesity increases the risk of health problems resulting from excess body fat.8 Epidemiologic factors such as age, race, gender, and socioeconomic status are influential components affecting the increasing rates of childhood obesity. The potential causes of childhood obesity are many. Diseases, genetic abnormalities, activity level and nutritional status of the child, and mass media and marketing can all lead to obesity in children. Screening tests, such as BMI, as well as other diagnostic tests and a detailed history and physical examination can be used to evaluate the weight and health of a child. The second article on childhood obesity discusses the physical and psychological consequences of childhood obesity as well as management and preventive strategies for this growing epidemic. JAAPA
Katie Perpich and Rachel Russ recently graduated from the Seton Hall University PA program in South Orange, New Jersey. Denise Rizzolo is an associate professor in the Seton Hall PA program and works at the Care
Station in Springfield, New Jersey. Mona Sedrak is an associate professor and program director of the Seton Hall PA program. The authors have indicated no relationships to disclose relating to the content of this article.
IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read
Childhood obesity: Complications, prevention strategies, treatment; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to
www.aapa.org and searching for keyword
JAAPA post-tests. All others may complete and submit the post-test online at no charge at
www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.
REFERENCES
1. Hall M, Hellmich M. Michelle Obama aims to end child obesity in a generation. USA Today. http://www.usatoday.com/news/health/weightloss/2010-02-09-1Afirstlady09_CV_N.htm. February 9, 2010; Health & Behavior. Accessed November 7, 2011.
2. Skelton JA, Cook SR, Auinger P, et al. Prevalence and trends of severe obesity among US children and adolescents. Acad Pediatr. 2009;9(5):322-329.
3. Ogden CL, Carroll MD, Curtin LR, et al. Prevalence of high body mass index in US children and adolescents, 2007-2008. JAMA. 2010;303(3):242-249.
4. Wang Y, Lobstein T. Worldwide trends in childhood overweight and obesity. Int J Pediatr Obes. 2006;1(1):11-25.
5. Ebbeling CB, Pawlak DB, Ludwig DS. Childhood obesity: public-health crisis, common sense cure. Lancet. 2002;360(9331):473-482.
6. Drewnowski A. Obesity and the food environment: dietary energy density and diet costs. Am J Prev Med. 2004;27(3 suppl):154-162.
7. Ludwig DS. Childhood obesity—the shape of things to come. N Engl J Med. 2007;357(23):
2325-2327.
8. Reilly JJ. Descriptive epidemiology and health consequences of childhood obesity. Best Pract Res Clin Endocrinol Metab. 2005;19(3):327-341.
9. Centers for Disease Control and Prevention. Obesity prevalence among low-income, preschool-aged children—United States, 1998-2008. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5828a1.htm. Reviewed July 23, 2009. Accessed November 7, 2011.
10. American Academy of Pediatrics. About childhood obesity. http://www.aap.org/obesity/about.html. Accessed November 7, 2011.
11. World Health Organization. Obesity and overweight. http://www.who.int/mediacentre/
factsheets/fs311/en/. Updated March 2011. Accessed November 7, 2011.
12. Singh G, Kogan M, Dyck P, Siahpush M. Racial/ethnic, socioeconomic, and behavioral determinants of childhood and adolescent obesity in the United States: analyzing independent joint associations. Ann Epidemiol. 2008;18(9):682-695.
13. Boumtje PI, Huang CL, Lee J-Y, Lin B-H. Dietary habits, demographics, and the development of overweight and obesity among children in the United States. Food Policy. 2005;30(2):115-128.
14. Wieting J. Cause and effect in childhood obesity: solutions for a national epidemic. J Am Osteopath Assoc. 2008;108(10):545-552.
15. Rosenberg DE, Sallis JF, Kerr J, et al. Brief scales to assess physical activity and sedentary equipment in the home. Int J Behav Nutr Phys Act. 2010;7:10
16. Schwimmer JB, Burwinkle TM, Varni JW. Health-related quality of life of severely obese children and adolescents. JAMA. 2003;289(14):1813-1819.
17. Kunkel D. Children and television advertising. In: Singer DG, Singer JL, eds. The Handbook of Children and the Media. Thousand Oaks, CA: Sage Publications; 2001:375-394.
18. Schlosser E. Fast Food Nation: The Dark Side of the All-American Meal. Boston, MA: Houghton Mifflin Co; 2001.
19. Kiess W, Blüher S, Kapellen T, et al. Physiology of obesity in childhood and adolescence. Curr Paediatrics. 2006;16(2):123-131.
20. Daniels SR, Greer FR; Committee on Nutrition. Lipid screening and cardiovascular health in childhood. Pediatrics. 2008;122(1):198-208.
21. Nihiser AJ, Lee SM, Wechsler H, et al. Body mass index measurement in schools. J Sch Health. 2007;77(10):651-671.
22. Freedman DS, Sherry B. The validity of BMI as an indicator of body fatness and risk among children. Pediatrics. 2009;124(suppl 1):S23-S34.
23. Speiser PW, Rudolf MC, Anhalt H, et al. Consensus statement: childhood obesity. J Clin Endocrinol Metab. 2005;90(3):1871-1887.
24. Centers for Disease Control and Prevention. About BMI for Children and Teens. http://www.cdc.gov/healthyweight/assessing/bmi/childrens_bmi/about_childrens_bmi.html. Updated September 13, 2011. Accessed November 7, 2011.
IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read
Childhood obesity: Complications, prevention strategies, treatment; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to
www.aapa.org and searching for keyword
JAAPA post-tests. All others may complete and submit the post-test online at no charge at
www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.