Childhood Overweight

Childhood obesity has more than tripled in the past 30 years. The prevalence of obesity among children aged 6 to 11 years increased from 6.5% in 1980 to 19.6% in 2008. The prevalence of obesity among adolescents aged 12 to 19 years increased from 5.0% to 18.1%.

Obesity is the result of caloric imbalance (too few calories expended for the amount of calories consumed) and is mediated by genetic, behavioral, and environmental factors. Childhood obesity has both immediate and long-term health impacts:

• Obese youth are more likely to have risk factors for cardiovascular disease, such as high cholesterol or high blood pressure. In a population-based sample of 5- to 17-year-olds, 70% of obese youth had at least one risk factor for cardiovascular disease.
• Children and adolescents who are obese are at greater risk for bone and joint problems, sleep apnea, and social and psychological problems such as stigmatization and poor self-esteem.
• Obese youth are more likely than youth of normal weight to become overweight or obese adults, and therefore more at risk for associated adult health problems, including heart disease, type 2 diabetes, stroke, several types of cancer, and osteoarthritis.

Healthy lifestyle habits, including healthy eating and physical activity, can lower the risk of becoming obese and developing related diseases.

Prevalence
In the past 30 years, the occurrence of overweight in children has doubled and it is now estimated that one in five children in the US is overweight. Increases in the prevalence of overweight are also being seen in younger children, including preschoolers. Prevalence of overweight is especially higher among certain populations such as Hispanic, African American and Native Americans where some studies indicate prevalence of >85th percentile of 35-40%. Also, while more children are becoming overweight, the heaviest children are getting even heavier. As a result, childhood overweight is regarded as the most common prevalent nutritional disorder of US children and adolescents, and one of the most common problems seen by pediatricians.

Consequences of Childhood Overweight
Both the short term and long term effects of overweight on health are of concern because of the negative psychological and health consequences in childhood.

Potential Negative Psychological Outcomes:

• Depressive symptoms
• Poor Body Image
• Low Self-Concept
• Risk for Eating Disorders

Negative Health Consequences:

• Insulin Resistance
• Type 2 Diabetes
• Hypertension
• High Total and LDL Cholesterol and triglyceride levels in the blood
• Low HDL Cholesterol levels in the blood
• Sleep Apnea
• Early puberty
• Orthopedic problems such as Blount's disease and slipped capital femoral epiphysis
• Non-alcoholic steatohepatitis (fatty infiltration and inflammation of the liver)

Further, obese children are more likely to be obese as adults, hence they are at increased risk for a number of diseases including: stroke, cardiovascular disease, hypertension, diabetes, and some cancers.

Contributors to Childhood Overweight

• Food Choices - diets higher in calories (including fats and simple sugars) and lower in fruits and vegetables are linked with overweight
• Physical Activity vs. Sedentary Activity - less physical activity and more time spent participating in activities such as watching tv results in less energy expenditure
• Parental Obesity - children of obese parents are more likely to be overweight themselves. There is an inherited component to childhood overweight that makes it easier for some children to become overweight than others. There are a number of single gene mutations ("genetic alterations") that are capable of causing severe childhood overweight, though these are rare. Even children with genetic risk for overweight will still only become overweight if they consume more calories than they use. Parental obesity may also reflect a family environment that promotes excess eating and insufficient activity.
• Eating Patterns - skipping meals or failure to maintain a regular eating schedule can result in increased intakes when food is eaten.
• Parenting Style - some researchers believe that excess parental control over children's eating might lead to poor self regulation of kid's energy intake.
• Diabetes during pregnancy - overweight and type 2 diabetes occur with greater frequency in the offspring of diabetic mothers (who are also more likely to be obese)
• Low Birth Weight - Low birth weight (<2500 g) is a risk factor for overweight in several epidemiological studies.
• Excessive weight gain during pregnancy - Several studies have shown that excessive maternal weight gain during pregancy is associated with increased birth weight and overweight later in life.
• Formula Feeding - Breast feeding is generally recommended over formula feeding. Although the exact mechanism in unknown, several long-term studies suggest that breast feeding may prevent excess weight gain as children grow.
• Parental Eating and Physical Activity Habits - Parents with poor nutritional habits and who lead sedentary lifestyles role model these behaviors for their children, thereby creating an "obesigenic" home environment.
• Demographic Factors. Certain demographic factors are associated with an increased risk of being overweight in childhood. For example, there is evidence that African-American and Hispanic children 6 to 11 years years old are more likely to be overweight than are non-Hispanic white children of the same age. Asian and Pacific Islander children of the same age were slightly less likely to be overweight.

Measuring Childhood Overweight
Childhood overweight is identified through the measurement of Body Mass Index or BMI. BMI can also be calculated using kilograms (kg) and meters (m), as well as pounds (lbs) and inches (in):

Once BMI is calculated, it can then be used to determine if a child is overweight or not, by comparing the BMI with the CDC growth charts (http://www.cdc.gov/growthcharts/) for children of the same age and sex. Children who have a BMI at or above the 95%, percentile for age and sex are considered overweight. Children with a BMI that falls between the 85%-95% are classified as at risk for overweight. To plot body mass index-for-age percentiles for boys, click here. To plot body mass index-for-age percentiles for girls, click here.

Parents whose children fall in the "at risk for overweight" category should discuss this with their pediatrician or family physician and should carefully monitor their child's growth. Parents whose children fall in the "overweight" category should make an appointment with their pediatrician or family physician to discuss whether treatment is warranted. Screening for other health risk factors (such as blood pressure or lipid profile) may be recommended by your physician. The BMI is just an initial tool in a series of examinations required to determine if your child is overweight. At no time should a child be diagnosed and labeled overweight by a parent, teacher, or other lay (non-medical) individual. Discussions concerning the child's weight should occur only after reviewing his or her condition with a medical professional.

Tips for Parents & Caregivers to Help Establish Healthy Eating Patterns with Kids

• Parents should choose what children can eat, (what foods and drinks are in the home, what foods and drinks are served at meals and snacks, what restaurants they go to, etc) but among those foods, parents should allow kids to choose whether they eat at all and how much to eat.
• Fruits and vegetables, as compared to high calorie snack foods (often high fat and high sugar), should be readily available in the home.
• Serve and eat a variety of foods from each food group.
• Use small portions - child portions are usually very small, particularly compared to adult portions. More food can always be added.
• Bake, broil, roast or grill meats instead of frying them.
• Limit use of high calorie, high fat and high sugar sauces and spreads.
• Use low-fat or nonfat and lower calorie dairy products for milk, yogurt and ice cream.
• Support participation in play, sports and other physical activity at school, church or community leagues.
• Be active as a family - Go on a walk, bike ride, swim or hike together. Limit TV time.
• Avoid eating while watching TV. TV viewers may eat too much, too fast, and are influenced by the foods and drinks that are advertised.
• Replace high-sugared drinks, espically sodas, with water and/or low fat milk.
• Limit fruit juice intake to two servings or less per day (one serving = ¾ cup) - Many parents allow their children unlimited intake of fruit juice (100%) because of the accompanying vitamins and minerals. However, children who drink too much fruit juice may be consuming excess calories.
• Encourage free play in young children and provide environments that allow children to play indoors and outdoors.
• Role model through actions healthy dietary practices, nutritional snacks, and lifestyle activities. Avoid badgering children, restrictive feeding, labeling foods as "good" or "bad," and using food as a reward.

Tips for Pediatricians & Other Health Care Professionals to Facilitate the Prevention of Childhood Overweight (from the American Academy of Pediatrics Policy Statement, August 2003).

Health Supervision Recommendations:

• Identify and track patients at risk by virtue of family history, birth weight, or socioeconomic, ethnic, cultural, or environmental factors.
• Calculate and plot BMI once a year in all children and adolescents.
• Use change in BMI to identify rate of excessive weight gain relative to linear growth.
• Encourage, support, and protect breastfeeding.
• Encourage parents and caregivers to promote healthy eating patterns by offering nutritious snacks, such as vegetables and fruits, low-fat dairy foods, and whole grains; encouraging children's autonomy in self-regulation of food intake and setting appropriate limits on choices; and modeling healthy food choices.
• Routinely promote physical activity, including unstructured play at home, in school, in child care settings, and throughout the community.
• Recommend limitation of television and video time to a maximum of 2 hours per day.
• Recognize and monitor changes in obesity-associated risk factors for adult chronic disease, such as hypertension, dyslipidemia, hyperinsulinemia, impaired glucose tolerance, and symptoms of obstructive sleep apnea syndrome.

Advocacy Recommendations:

• Help parents, teachers, coaches, and others who influence youth to discuss health habits, not body habitus, as part of their efforts to control overweight.
• Enlist policy makers from local, state, and national organizations and schools to support a healthful lifestyle for all children, including proper diet and adequate opportunity for regular physical activity.
• Encourage organizations that are responsible for health care and health care financing to provide coverage for effective obesity prevention and treatment strategies.
• Encourage public and private sources to direct funding toward research into effective strategies to prevent overweight and to maximize limited family and community resources to achieve healthful outcomes for youth.
• Support and advocate for social marketing intended to promote healthful food choices and increased physical activity.

References:

American Academy of Pediatrics. Prevention of Pediatric Overweight and Obesity: American Academy of Pediatrics Policy Statement; Organizational Principles to Guide and Define the Child Health System and/or Improve the Health of All Children; Committee on Nutrition. Pediatrics. 2003;112:424-430

Banis HT, Varni JW, Wallander JL, Korsch BM, Jay SM, Adler R, Garcia-Temple E, & Negrete V. Psychological and social adjustment of obese children and their families. Child: Care, Health, and Development. 1998;14,157-173.

Barker M. Birthweight and body fat distribution in adolescent girls. Arch Dis Child 1997; 77(5): 381-383.

Barlow SE, & Dietz WH. Obesity evaluation and treatment: Expert Committee recommendations. Pediatrics, 1998; 102(3): URL:http://www.pediatrics.org/cgi/content/full/102/3/e29.

Bouchard C and Perusse L. Heredity and body fat. Annual Review of Nutrition, 1988;8:259-77.

Dietz WH. Childhood Weight affects adult morbidity and morality. J Nutr, 1998;128 (2):411S-414S.

Ebbeling CB, Pawlak DB, Ludwig DS. Childhood obesity: public health crisis, common sense cure. Lancet 2002, 360:473-82.

Gortmaker SL, Must A, Sobol AM, Peterson K, Colditz GA, Dietz WH. Television viewing as a cause of increasing obesity among children in the United States, 1986-1990. Arch Pediatr Adolesc Med. 1996;150(4):356-62.

Satter E. How to Get Your Kid to Eat...But Not Too Much. Bull Publishing Company, 1987.

Haas JS. Lee LB. Kaplan CP. Sonneborn D. Phillips KA. Liang SY. The association of race, socioeconomic status, and health insurance status with the prevalence of overweight among children and adolescents. American Journal of Public Health. 93(12):2105-10, 2003

Johnson SL, Birch LL. Parents' and children's adiposity and eating style. Pediatrics, 1994;94:653-661.

Kinnunen TI, Luoto R, Gissler M, Hemminki E. Pregancy weight gain from 1960s to 2000 n Finland. Int J Obes 2003; 27:1572-77.

Kuczmarski RJ, Ogden CL, Grummer-Strawn LM, et al. CDC growth charts: United States. Advance data from vital and health statistics; no 314. Hyattsville, Maryland: National Center for Health Statistics. 2000.

Malina RM, Katmarzyk PT, Beunen G. Birth weight and its relationship to size attained and relative fat distribution at 7 to 12 years of age. Obesity Research 1996; 4(4): 385-390.

Obarzanek E, Schreiber GB, Crawford PB, Goldman SR, Barrier PM, Frederick MM, & Lakatos E. Energy intake and physical activity in relation to indexes of body fat: The NHLBI Growth and Health Study. Am J Clin Nutr, 1994;60:15-22.

Sallis JF. Epidemiology of physical activity and fitness and adolescents. Critical Reviews in Food Science and Nutrition, 1993;33:403-408.

Shapiro C, Sutija VG, Bush J. Effect of maternal weight gain on infant birth weight. J Perinat Med 2000; 28:428-31.

Troiano RP and Flegal KM. Overweight children and adolescents: Descroption, epidemiology, and demographics. Pediatrics, 1998;101(3):497-504.

 

Childhood Overweight

by L. Bellows and J. Roach¹ (05/09)

Quick Facts...

• Overweight children have an increased risk of being overweight as adults.
• Genetics, behavior, and family environment play a role in childhood overweight.
• Childhood overweight increases the risk for certain medical and psychological conditions.
• Encourage overweight children to be active, decrease screen time, and develop healthful eating habits.

The prevalence of overweight children in the United States has increased dramatically in recent years. Recent reports have reached epidemic levels, with approximately 16 percent of children, 2 to 19 years old, classified as overweight.² Colorado fares slightly better with close to 14 percent of children considered overweight; however, the same increasing trend seen nationally is occurring in Colorado as well.³ Excess weight has both immediate and long-term consequences and the current issue demands serious attention.

Definitions

Body Mass Index (BMI) is a measure of weight adjusted for height used to determine weight categories. Due to children’s changing body compositions over time and the different growth rates of boys and girls, BMI for children is age and gender specific. BMI for age is determined using gender-specific growth charts that place a child in a percentile relative to weight and height. Weight categories are determined based on these percentiles and are defined as:

Underweight < 5th percentile
Normal 5th to < 85th percentile
At risk of overweight 85th to <95th percentile
Overweight 95th percentile and above

The terms obese and overweight are often used interchangeably, although the terms at risk of overweight and overweight are preferred to reference children whose excess body weight poses medical risks.

Consequences of Childhood Overweight

Overweight children and adolescents are at increased risk for several health complications. During their youth, for example, they are more likely to exhibit risk factors for cardiovascular disease (CVD) including high blood pressure, high cholesterol, dyslipidemia, and type 2 diabetes compared with normal weight individuals.⁴ Additional health complications associated with overweight children include sleep apnea, asthma, and liver damage.⁴⁴⁴ This study also concluded that if overweight begins before 8 years of age, obesity in adulthood is likely to be more severe. Finally, childhood overweight has psychological and emotional consequences. Overweight children are at an increased risk of teasing and bullying, low self-esteem, and poor body image. Further, overweight children and adolescents are more likely to become obese adults. For example, one study found that approximately 80 percent of children who were overweight at 10 to 15 years old were obese at 25. Another study found that 25 percent of obese adults were overweight as children.

Contributors of Childhood Overweight

There is not one single cause of childhood overweight, rather it is a complex interaction of many variables. Contributing factors include genetics, behavior, environment, and certain socio-demographics.

Genetics. Certain genetic characteristics may increase an individual’s susceptibility to excess body weight, however, there are likely to be many genes involved and a strong interaction between genetics and environment that influences the degree of excess body weight.⁵ It has been shown that overweight tends to run in families suggesting a genetic link. In some cases, parental obesity is a stronger predictor of childhood overweight than the child’s weight status alone.⁵

Behavior. Weight gain occurs as a result of energy imbalance, specifically when a child consumes more calories than the child uses. Several behaviors can contribute to weight gain including nutrition, physical activity, and sedentary behaviors.

• Nutrition - An increase in availability and consumption of high-calorie convenience foods and beverages, more meals eaten away from home, fewer family meals, and greater portion sizes all may contribute to childhood overweight. Further, many children’s diets do not meet nutrition guidelines. For example, only 8 percent of children in Colorado ate vegetables three or more times per day as recommended by the U.S. Department of Agriculture.^{3, 6}
• Physical Activity - Decreased opportunities and participation in physical activity is another behavior that contributes to overweight children. Being physically active not only has positive effects on body weight, but also on blood pressure and bone strength.⁷ It also has been shown that physically active children are more likely to remain physically active into adolescence and adulthood.⁷ Children may spend less time being physically active during school as well as at home. School physical education programs have decreased and children are walking to school and doing household chores less frequently.
• Screen Time - While physical activity levels have decreased, sedentary behaviors, such as watching television, playing on the computer and with video games have increased. One study found that time spent watching television, videos, DVDs, and movies averaged slightly over three hours per day among children 8 to 18 years old.⁶ Several studies have found a positive association between time spent watching television and prevalence of overweight in children. Sedentary behavior, and specifically television viewing, may replace time children spend in physical activities, contribute to increased calorie consumption through excessive snacking and eating meals in front of the television, influence children to choose high-calorie, low-nutrient foods through exposure to food advertisements, and decrease children’s metabolic rate.⁶

Environment. There are a variety of environmental factors that can potentially contribute to childhood overweight, including home, childcare settings, school, and the community. The school and community settings are other environments where children learn about eating and physical activity habits. It is becoming increasingly important for all children to have access to healthful food choices and safe physical activity opportunities. Advocating for innovative school nutrition and physical activity programs as well as ensuring that there are well-lit sidewalks, bike paths, and parks in the community can all help to shift towards a more healthful environment for our children.

Socio-Demographics. Certain ethnic minority and socioeconomic populations have increased rates of childhood overweight.⁸ Low-income families face numerous barriers including food insecurity, lack of safe places for physical activity, and lack of consistent access to healthful food choices, especially fruits and vegetables.⁵ Recent reports also indicate racial disparities, with the greatest prevalence among Mexican American boys and African American non-Hispanic girls.² With both sexes combined, roughly 21 percent of both Mexican Americans and African American non-Hispanics are overweight compared to close to 15 percent for white non-Hispanic.²

Promoting Healthy Habits and a Healthy Weight

Lifestyles and behaviors are established early in life; therefore, a focus on healthful behaviors is vital to promoting healthy weight. The primary goals of overcoming childhood overweight should be healthful eating and increased activity. It is important for children to consume enough calories to support normal growth and development without promoting excessive weight gain. The home, childcare setting, school, and community are all integral to a more healthful environment for our children.

Parents, caregivers, teachers, and community members can promote healthy nutrition and physical activity habits and a healthy weight among children by:

Encouraging Healthy Eating Habits

• Serve a wide variety of foods, including fruits, vegetables, whole grains, and low-fat dairy products. Provide children with a variety of foods to ensure they get all the nutrients they need for proper growth and development.
• Know how much food kids need. Keep portion sizes in check to help children maintain their sense of self-regulation –and to know when they are hungry and when they are full.
• Be a good role model for kids by eating together. Eating meals as a family has been shown to increase fruit and vegetable consumption and decrease the amount of junk foods and sugar-sweetened beverages.
• Visit USDA’s MyPyramid website (www.mypyramid.gov) for information and tips for eating healthfully.⁶

Promoting Physical Activity

• Aim for children to accumulate a minimum of 60 minutes of moderate-to-vigorous physical activity each day. Activity bouts can be all at once or in several bouts spread throughout the day.
• Increase opportunities for children to engage in physical activity throughout the day. Incorporating daily recess and physical education into the school day will help ensure that children are getting the recommended 60 minutes of physical activity each day.
• Be a good role model. Engage in activity with children.
• Limit screen and television time to less than two hours per day. Keep televisions and video games out of children’s bedrooms to help them limit the amount of screen time.
• Visit the National Institutes of Health’s WeCan™ (Ways to Enhance Children’s Activity and Nutrition) website (www.wecan.org) for ideas on increasing physical activity, decreasing screen time, and improving food choices among children.⁹

References

²Ogden, C. L., Carroll, M. D., & Flegal, K. M. (2008). High body mass index for age among US children and adolescents, 2003-2006. JAMA, 299(20), 2401-2405.

³Colorado Department of Public Health and Environment, Colorado Physical Activity and Nutrition program. (2006). Overweight, Physical Activity and Nutrition Among Colorado Children and Youth: A Data Resource. Retrieved February 27, 2009 from http://www.cdphe.state.co.us/pp/COPAN/olderadult/childfactsheet04.pdf

⁴Centers for Disease Control and Prevention. (2009). Overweight and Obesity. Consequences. Retrieved February 27, 2009 from http://www.cdc.gov/NCCDPHP/DNPA/obesity/childhood/consequences.htm

⁵American Academy of Pediatrics. (2003). Policy statement. Prevention of pediatric overweight and obesity. Pediatrics, 112(2), 424-430.

⁶United States Department of Agriculture. (2009). MyPyramid: Steps to a Healthier You. Retrieved February 27, 2009 from http://www.mypyramid.gov

⁷Centers for Disease Control and Prevention. (2009). Overweight and Obesity. Contributing Factors. Retrieved February 27, 2009 from http://www.cdc.gov/obesity/childhood/causes.html

⁸Institute of Medicine. (2004). Childhood Obesity in the United States: Facts and Figures. Retrieved February 27, 2009 from http://www.iom.edu/Object.File/Master/22/606/FINALfactsandfigures2.pdf

⁹National Heart, Lung, and Blood Institute. (2009). WeCan! Ways to Enhance Children’s Activity and Nutrition. Retrieved February 27, 2009 from http://www.wecan.org