Basics About Childhood Obesity

How is childhood overweight and obesity measured?

Body mass index (BMI) is a measure used to determine childhood overweight and obesity. It is calculated using a child's weight and height. BMI does not measure body fat directly, but it is a reasonable indicator of body fatness for most children and teens.

A child's weight status is determined using an age- and sex-specific percentile for BMI rather than the BMI categories used for adults because children's body composition varies as they age and varies between boys and girls.

CDC Growth Charts are used to determine the corresponding BMI-for-age and sex percentile. For children and adolescents (aged 2—19 years):

• Overweight is defined as a BMI at or above the 85th percentile and lower than the 95th percentile for children of the same age and sex.¹
• Obesity is defined as a BMI at or above the 95th percentile for children of the same age and sex.¹

What are the consequences of childhood obesity?

Health risks now

• Childhood obesity can have a harmful effect on the body in a variety of ways. Obese children are more likely to have–
• High blood pressure and high cholesterol, which are risk factors for cardiovascular disease (CVD). In one study, 70% of obese children had at least one CVD risk factor, and 39% had two or more.²
• Increased risk of impaired glucose tolerance, insulin resistance and type 2 diabetes.³
• Breathing problems, such as sleep apnea, and asthma.^4,5
• Joint problems and musculoskeletal discomfort.^4,6
• Fatty liver disease, gallstones, and gastro-esophageal reflux (i.e., heartburn).^3,4
• Obese children and adolescents have a greater risk of social and psychological problems, such as discrimination and poor self-esteem, which can continue into adulthood.^3,7,8

Health risks later

• Obese children are more likely to become obese adults.^{9, 10, 11}   Adult obesity is associated with a number of serious health conditions including heart disease, diabetes, and some cancers.¹²
• If children are overweight, obesity in adulthood is likely to be more severe.¹³

References

1. Barlow SE and the Expert Committee. Expert committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics 2007;120 Supplement December 2007:S164—S192.
2. Freedman DS, Mei Z, Srinivasan SR, Berenson GS, Dietz WH. Cardiovascular risk factors and excess adiposity among overweight children and adolescents: the Bogalusa Heart Study. J Pediatr. 2007;150(1):12—17.e2.
3. Whitlock EP, Williams SB, Gold R, Smith PR, Shipman SA. Screening and interventions for childhood overweight: a summary of evidence for the US Preventive Services Task Force. Pediatrics. 2005;116(1):e125—144.
4. Han JC, Lawlor DA, Kimm SY. Childhood obesity. Lancet. May 15 2010;375(9727):1737—1748.
5. Sutherland ER. Obesity and asthma. Immunol Allergy Clin North Am. 2008;28(3):589—602, ix.
6. Taylor ED, Theim KR, Mirch MC, et al. Orthopedic complications of overweight in children and adolescents. Pediatrics. Jun 2006;117(6):2167—2174.
7. Dietz W. Health consequences of obesity in youth: Childhood predictors of adult disease. Pediatrics 1998;101:518—525.
8. Swartz MB and Puhl R. Childhood obesity: a societal problem to solve. Obesity Reviews 2003; 4(1):57—71.
9. Biro FM, Wien M. Childhood obesity and adult morbidities. Am J Clin Nutr. May 2010;91(5):1499S—1505S.
10. Whitaker RC, Wright JA, Pepe MS, Seidel KD, Dietz WH. Predicting obesity in young adulthood from childhood and parental obesity. N Engl J Med 1997;37(13):869—873.
11. Serdula MK, Ivery D, Coates RJ, Freedman DS. Williamson DF. Byers T. Do obese children become obese adults? A review of the literature. Prev Med 1993;22:167—177.
12. National Institutes of Health. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: the Evidence Report. Bethesda, MD: National Institutes of Health, U.S. Department of Health and Human Services; 1998.
13. Freedman DS, Khan LK, Dietz WH, Srinivasan SR, Berenson GS. Relationship of childhood overweight to coronary heart disease risk factors in adulthood: The Bogalusa Heart Study. Pediatrics 2001;108:712—718.

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