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childhood obesity The development of
unhealthy body weight due to excessive body fat
before adulthood (age 18). Childhood OBESITYhas
numerous health consequences that affect METAB-
OLISM, physical growth and development, and
PUBERTY. Childhood obesity jumped significantly
between 1970 and 2000. Currently 15 percent of
US children have obesity. Another 20 percent are
overweight, which places them at risk for obesity.
Health experts attribute the rise in childhood
obesity primarily to EATING HABITS and physical
inactivity. Ongoing health assessment monitoring,
such as the periodic National Health and Nutrition
Examination Survey (NHANES) and the Behav-
ioral Risk Factor Surveillance System (BRFSS),
reveals a steady decline in the level of physical
activity among young people, including through
physical education programs in the schools.
Increasing the physical activity of children as a
mechanism for improving long-term health is
among the objectives of HEALTHYPEOPLE 2010 , the
US government’s agenda for community health.
Researchers also continue to explore other factors
that may contribute to obesity. Much attention
focuses on the role of genetics and regulation of
metabolic processes within the body such as the
release and activity of hormones.

Diagnosing Childhood Obesity

Conventional methods of assessing BODY FAT PER-

CENTAGEand BODY MASS INDEX(BMI), the standard

measures of obesity, are somewhat different for

children from those used for adults. A child’s body

fat varies with developmental stages and growth

cycles. Correspondingly, a child’s BMI varies

according to age and developmental stage. As

well, boys and girls have different body fat compo-

sition through the end of ADOLESCENCE.

In 2001 the US Centers for Disease Control and

Prevention (CDC) developed gender-specific BMI-

for-age charts to provide guidelines for assessing

underweight, healthy weight, and overweight in

children between the ages of 2 and 20. The charts

correlate BMI to percentile, a measure of relative

comparison that allows monitoring of BMI

through the entire course of childhood. The

boundary for overweight is the 85th percentile (85

percent of children who are the same age and

gender have a lower BMI) and for obesity the

95th percentile (95 percent of children who are

the same age and gender have a lower BMI).

Health Implications of Obesity in Childhood

Doctors are seeing INSULIN RESISTANCE, type 2 DIA-

BETES, HYPERTENSION(high BLOOD PRESSURE), HYPER-

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BMI FOR AGE FOR CHILDREN AND TEENS: KEY PERCENTILE MARKERS

BMI for Age: Boys/Girls BMI for Age Percentile Health Status for Body Weight
2 years 7 years 15 years 20 years

14.8/14.4 13.7/13.4 16.6/16.3 19.1/17.8 5th underweight

18.2/18.0 17.4/19.2 23.4/24.0 27.1/26.5 85th overweight or at risk for overweight

19.3/19.1 19.1/19.6 26.8/28.1 30.6/31.8 95th obesity