Obesity is an abnormal accumulation of body fat, usually 20 percent or
more over an individual's ideal body weight. Obesity is associated
with increased risk of illness, disability, and death.
The branch of medicine that deals with the study and treatment of obesity
is known as bariatrics. As obesity has become a major health problem in
the United States, bariatrics has become a separate medical and surgical
Childhood obesity is in the early 2000s a significant health problem in
the United States. Obese children and adolescents are at increased risk
for developing diabetes,
, coronary artery disease,
apnea, orthopedic problems, and psychosocial disorders.
Obesity involves excessive weight gain and fat accumulation. For children
and adolescents, obesity is defined in terms of body mass index (BMI)
percentile. BMI is a formula that considers an individual's height
and weight to determine body fat and health risk, and it is used
differently for children and adolescents than it is for adults. In adults,
BMI often misrepresents obesity because it does not consider healthy
weight from muscle tissue; therefore, body fat percentage is considered a
more accurate method for determining obesity in adults. In children and
adolescents, because body fat changes as they mature, BMI is gender- and
age-specific and plotted on gender-specific growth charts to determine
BMI-forage. Curved lines on the chart (percentiles) are used by healthcare
professionals to identify children and adolescents at risk for overweight
and obesity. Children and adolescents with a BMI-for-age in the 85th to
95th percentile are considered overweight and at risk for obesity, and
those with a BMI-for-age greater than the 95th percentile are considered
According to the American Obesity Association and the Centers for Disease
Control and Prevention, 30.3 percent of children aged six to 11 years are
overweight and 15.3 percent are obese, and 30.4 percent of adolescents
aged 12 to 19 years are overweight and 15.5 percent are obese. From 1980
to 2004, the prevalence of obesity among children quadrupled, and the
prevalence of obesity in adolescents more than doubled. Overweight and
obesity is more prevalent in boys (32.7%) than girls (27.8%). Obesity is
more common in African American, Hispanic American, and Native American
children and adolescents, than among Caucasians of the same ages.
Causes and symptoms
Although obesity can be a side effect of certain hormonal disorders or use
of certain medications, the primary cause of obesity in children and
adolescents is excess calorie consumption coupled with a sedentary
lifestyle. Children and adolescents living in the twenty-first century are
the most inactive generation ever. The majority of schools no longer offer
daily physical education classes; and active leisure activities, such as
bicycle riding, have been replaced by sedentary activities, such as
television watching and playing computer games. Studies have documented
dramatic changes in childhood food consumption from the 1970s to 2004.
Fast foods and foods eaten at other restaurants have increased by 300
percent since 1977, and soft drink consumption has also increased
significantly. In addition, standard meal portion sizes and snacking have
Obesity is the result of a complex interaction of genetics and
environmental factors. Genetics influence how the body regulates appetite
and metabolism, while certain environmental factors encourage excess
consumption. The body requires a certain amount of energy for basic
metabolism and to support additional physical activity. When calories
consumed from food and beverages equal calories expended during physical
activity, body weight is maintained. When calories consumed exceed
calories expended, weight gain results. To gain one pound, 3,500
additional calories must be consumed. In American society, excess calories
are easily consumed just by drinking soft drinks and eating
"supersized" fast food meals. A sedentary lifestyle results
in far fewer calories being burned daily.
The major symptoms of obesity are excessive weight gain and the presence
of large amounts of fatty tissue. Obesity can cause a number of other
conditions, including type 2 diabetes, hypertension,
, and gallstones. Type 2 diabetes, previously referred to as adult-onset
diabetes, has increased dramatically in children, and this increase has
been directly linked to obesity.
Overweight and obese children should be evaluated by a physician for
diabetes, hypertension, high cholesterol, and other medical conditions
that are influenced by excessive weight gain. Primary care physicians can
be consulted for weight management counseling to help children lose
Obesity in children and adolescents is diagnosed using the BMI-for-age
formula described above, which is used to define obesity. Comorbid
conditions, such as diabetes and high cholesterol, are diagnosed using
medical laboratory tests.
As of 2004, no weight loss drugs were approved for use in children,
although some drugs used to treat obesity are approved for use in
adolescents age 16 years and older. A few drugs are under investigation
for use in children. Although no drugs are specifically approved for
pediatric weight loss, some physicians may prescribe them
"off-label." Because the side effects of these medications
in children are unknown, children should not use adult weight loss drugs.
For extremely obese adolescents, surgical procedures—called
bariatric surgery—may be performed, but only rarely. These
procedures involve significant surgical alteration of the digestive tract
and require substantial modification of diet after the surgery to much
less than 1,000 calories per day. The long-term effects on growth and
development from severe postoperative calorie restriction are not unknown,
and weight loss surgery should only be performed on adolescents as a last
The most effective treatment for obese children and adolescents is
behavior and lifestyle modification under the guidance of a physician or
weight management specialist experienced in dealing with children and
adolescents. Behavior and lifestyle modification involves the following:
Alternatives for weight loss involve the use of ephedra-containing drugs
or herbal preparation or the use of diuretics and
. Both of these practices are unsafe, especially for children and
adolescents. Because ephedra can cause severe cardiac side effects, the
Food and Drug Administration has issued warnings against its use.
Diuretics and laxatives can result in severe
and improper absorption of nutrients.
Acupressure and acupuncture can suppress food cravings. Visualization and
meditation can create and reinforce a positive self-image that enhances
the patient's determination to lose weight. By improving physical
strength, mental concentration, and emotional serenity,
can provide the same benefits.
Given the drastic increase in childhood obesity, special summer programs
and therapeutic schools have been formed to help children lose weight.
Summer camp programs that focus on healthy eating and exercise habits are
available for overweight and obese children. In addition, in early 2004,
for overweight and obese children, which operates like other private and
charter schools, but with a focus on healthy weight loss and maintenance,
This graph shows the increasing numbers of overweight children in
the United States.
(Illustration by GGS Information Services.)
Obese and overweight children and adolescents are more likely to be obese
or overweight as adults. According to the American Obesity Association,
obese children aged 10 to 13 have a 70 percent chance of remaining obese
for the rest of their lives. Obese individuals are at increased risk for
many other diseases and early death. Behavior and lifestyle modification
programs involving positive goal-setting, increased exercise, and group
support can help children and adolescents successfully and safely lose
Obesity can be prevented by instilling healthy eating and regular exercise
habits in children at an early age. Minimizing and structuring daily time
for sedentary activities like television viewing and encouraging outdoor
activities such as bicycle riding, walking, running, and active
, and active indoor activities such as dancing can help increase physical
activity. Dietary modifications to help prevent obesity include limiting
soft drink and fast food consumption, monitoring food portion sizes, and
providing a well-balanced diet.
—The branch of medicine that deals with the prevention and
treatment of obesity and related disorders.
—A peptide hormone secreted by cells in the lining of the
stomach. Ghrelin is important in appetite regulation and maintaining the
body's energy balance.
—A condition characterized by abnormally high levels of lipids in
—Excessive weight gain in childhood, characterized by an increase
in the number of new fat cells.
—Abnormally high arterial blood pressure, which if left untreated
can lead to heart disease and stroke.
—Excessive weight gain in adulthood, characterized by expansion
of already existing fat cells.
—Weight corresponding to the lowest death rate for individuals of
a specific height, gender, and age.
—A protein hormone that affects feeding behavior and hunger in
humans. As of 2004 it is thought that obesity in humans may result in
part from insensitivity to leptin.
The following nutritional guidelines can help in the management of
Parents of obese children and adolescents should be concerned for their
current and future health, since obesity can result in diabetes,
hypertension, and coronary artery disease. Losing weight can be very
difficult for obese children, and parental support is essential for
success. Because children model behavior after their parents, obesity
often affects both parents and children. Parents should strive to have
healthy eating habits and exercise regularly to be effective role models
for their children. Making healthy eating and exercise a family priority
is better for everyone and helps reinforce positive changes in behavior
for the obese child.
Obese children and adolescents are more susceptible to eating disorders,
and body image, and depression due to peer influences. Counseling, peer
group therapy, and
may be required to support lifestyle modifications for obese children and
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Web site: http://www.eatright.org.
American Obesity Association (AOA).
1250 24th Street NW, Suite 300, Washington, DC 20037. Web site:
American Society of Bariatric Physicians.
5453 East Evans Place, Denver, CO 80222–5234. Web site:
American Society for Bariatric Surgery.
7328 West University Avenue, Suite F, Gainesville, FL 32607. Web site:
National Institute of Diabetes and Digestive and Kidney
31 Center Drive, USC2560, Building 31, Room 9A-04, Bethesda, MD
20892–2560. Web site: http://www.niddk.nih/gov.
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