DescriptionChildhood obesity is of increasing concern as a
public health problem in the United States. Over-
weight and obesity are defined by most healthcare
professionals using the Body Mass Index (BMI).
BMI is a calculation that compares a person’s weight
and height to arrive at a specific number. For details of
how to calculate BMI see the body mass index entry.
Children between the ages of 2 and 19 are assigned
a percentile based on their BMI number. The percen-
tile tells them how their weight compares to that of
other children who are their same age and gender. For
example, if a boy is in the 65th percentile for his age
group, 65 of every 100 children who are his age weigh
less than he does and 35 of every 100 weigh more than
he does. Adult BMI is interpreted differently.
The BMI weight categories for children are:
Below the 5th percentile: Underweight
5th percentile to less than the 85th percentile:
Healthy weight
85th percentile to less than the 95th percentile: At
risk of overweight
95th percentile and above: Overweight
There is some debate about what to call children
who are in the at risk for overweight and overweight
categories. Some healthcare organizations such as the
American Obesity Association use the term over-
weight for those at or above the 85th percentile and
obese for those at or above the 95th percentile. The
National Institutes of Health prefers to avoid apply-
ing the term obese to children, in part because of the
social stigma the word carries. Whatever term is used
to describe children in the top 15th percentile, thesechildren are at risk of developing health problems
because of their weight.Demographics
There is no doubt that American children are
getting heavier, and although the problem of over-
weight is growing fastest in the United States, the
trend toward heavier children is occurring in most in
most developed countries. In the United States, the
National Center for Health Statistics has tracked
children’s weight for several decades and recorded
the following changes in the percent of children who
are overweight (above the 85th percentile):
Children ages 2–5: 1971–74 5% 1988–94 7.2% 2003–
04 13.9%
Children ages 6–11: 1971–74 4% 1988–94 11.3%
2003–04 18.8%
Children ages 12–19: 1971–74 6.1% 1988–94 10.5%
2003–04 17.4%
In terms of numbers, this means that 12.5 million
children were overweight in 2003–04. During the
same time, 32.2% of adults, or 66 million people,
were obese. Other surveys have found the total obe-
sity rate among children and adolescents to be
between 21% and 24%.
Significant differences exist in the number of chil-
dren who are overweight in different races and ethnic
groups, and these mirror the differences in the adult
population. Significantly more Mexican American boys
are overweight than non-Hispanic black or white boys.
Significantly more Mexican American girls and non-
Hispanic black girls are overweight than white girls.
Native Americans and Hawaiians also have higher
rates of overweight than whites.Causes and symptoms
At its simplest, overweight is caused by taking in
more calories than the body uses. This difference isRisks associated with childhood obesityCardiovascular disease
Degenerative joint disease
Depression
Early puberty and early start of menstruation in girls
Eating disorders
Exposure to social prejudice and discrimination
Fat accumulation in the liver (fatty liver/liver disease)
Gallbladder disease
High cholesterol
Hypertension
Increased anxiety and stress
Joint pain
Low self-esteem
Sleep apnea
Type 2 diabetes mellitus(Illustration by GGS Information Services/Thomson Gale.)KEY TERMS
Hypothyroidism—disorder in which the thyroid
gland in the neck produces too little thyroid hor-
mone. One of the functions of thyroid hormone is
to regulate metabolic rate.
Type 2 diabetes—sometime called adult-onset dia-
betes, this disease prevents the body from properly
using glucose (sugar).Childhood obesity