OBESITY
Obesity
is defined as the presence of excess adipose (fatty) tissue
in the body. The term "overweight" may connote a milder degree of
excess fat than "obesity," but there are no clearly defined
criteria to distinguish between the two terms. Thus, the two
terms are
used interchangeably.1
Although
its underlying causes are not fully understood, obesity is
a complex chronic disease involving genetics, metabolism,
and physiology, as well as environmental and psychosocial
factors. Unhealthy eating behaviors and low levels of physical
activity are contributing to the continuing increase in the
prevalence of obesity among children and adolescents.2
Significance
Obesity
is a major public health problem. Studies have shown a dramatic
increase in the prevalence of obesity among children (including
those younger than 5 years of age) and adolescents.3,4 Data
from the National Center for Health Statistics (NCHS) indicate
that more than 1 in 5 children and adolescents in the United
States are overweight.3
Few
studies have examined the long-term effect of childhood
or adolescent obesity on adult morbidity and mortality.
Longitudinal studies of children followed into young adulthood
suggest that overweight children may become overweight
adults, particularly if obesity is present during adolescence.5–7 Overweight
during adolescence affects blood pressure and blood lipid,
lipoprotein, and insulin levels in adolescents.8 Perhaps
the most widespread consequences of childhood and adolescent
obesity are psychosocial, including discrimination.8,9
Health professionals
need to be aware of the demographic and personal risk factors
for childhood and adolescent obesity and be diligent in
their prevention efforts and screening.2 Children
and adolescents are considered at high risk for overweight
if
In addition, members
of certain racial/ethnic groups such as African-American
female children and adolescents and Hispanic and American
Indian/Alaska Native children and adolescents are considered
at high risk for overweight.2–4
Prevention
Enough
is known to guide efforts to reverse the trend of increasing
obesity.2 Because obesity
is difficult to treat, efforts need to focus on prevention.
Although genetic influences largely determine whether a child
or adolescent will become overweight, environmental influences
may determine the manifestation and extent of obesity.
The
primary strategies for preventing obesity are healthy eating
behaviors (see the Nutrition
chapter), regular physical activity, and reduced sedentary
behaviors (e.g., watching television and videotapes, playing
computer games). These strategies are part of a healthy lifestyle
that should be developed during early childhood. The goal
is to promote and model positive attitudes toward eating
and physical activity without emphasizing body weight. Behavioral
techniques are needed to encourage healthy eating and physical
activity behaviors.
