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Children's Health
Obesity
 Between 5-25 percent of children and teenagers in the United States are
obese (Dietz, 1983). As with adults, the prevalence of obesity in the
young varies by ethnic group. It is estimated that 5-7 percent of White
and Black children are obese, while 12 percent of Hispanic boys and 19
percent of Hispanic girls are obese (Office of Maternal and Child Health,
1989).
Some data indicate that obesity among children is on the increase. The
second National Children and Youth Fitness Study found 6-9 year olds to
have thicker skinfolds than their counterparts in the 1960s (Ross &
Pate, 1987). During the same period, others documented a 54 percent
increase in the prevalence of obesity among 6-11 year olds (Gortmaker,
Dietz, Sobol, & Wehler, 1987).
Defining Obesity in Children and Adolescents
Obesity is defined as an excessive accumulation of body fat. Obesity is
present when total body weight is more than 25 percent fat in boys and
more than 32 percent fat in girls (Lohman, 1987). Although childhood
obesity is often defined as a weight-for-height in excess of 120 percent
of the ideal, skinfold measures are more accurate determinants of fatness
(Dietz, 1983; Lohman, 1987).
A trained technician may obtain skinfold measures relatively easily in
either a school or clinical setting. The triceps alone, triceps and
subscapular, triceps and calf, and calf alone have been used with children
and adolescents. When the triceps and calf are used, a sum of skinfolds of
10-25mm is considered optimal for boys, and 16-30mm is optimal for girls
(Lohman, 1987).
Not all obese infants become obese children, and not all obese children
become obese adults. However, the prevalence of obesity increases with age
among both males and females (Lohman, 1987), and there is a greater
likelihood that obesity beginning even in early childhood will persist
through the life span (Epstein, Wing, Koeske, & Valoski, 1987).
Obesity presents numerous problems for the child. In addition to
increasing the risk of obesity in adulthood, childhood obesity is the
leading cause of pediatric hypertension, is associated with Type II
diabetes mellitus, increases the risk of coronary heart disease, increases
stress on the weight-bearing joints, lowers self-esteem, and affects
relationships with peers. Some authorities feel that social and
psychological problems are the most significant consequences of obesity in
children.
Causes of Childhood Obesity
As with adult-onset obesity, childhood obesity has multiple causes
centering around an imbalance between energy in (calories obtained from
food) and energy out (calories expended in the basal metabolic rate and
physical activity). Childhood obesity most likely results from an
interaction of nutritional, psychological, familial, and physiological
factors.
- The Family
The risk of becoming obese is greatest among children who have two
obese parents (Dietz, 1983). This may be due to powerful genetic factors
or to parental modeling of both eating and exercise behaviors,
indirectly affecting the child's energy balance. One half of parents of
elementary school children never exercise vigorously (Ross & Pate,
1987).
- Low-energy Expenditure
The average American child spends several hours each day watching
television; time which in previous years might have been devoted to
physical pursuits. Obesity is greater among children and adolescents who
frequently watch television (Dietz & Gortmaker, 1985), not only
because little energy is expended while viewing but also because of
concurrent consumption of high-calorie snacks. Only about one-third of
elementary children have daily physical education, and fewer than
one-fifth have extracurricular physical activity programs at their
schools (Ross & Pate, 1987).
- Heredity
Since not all children who eat non-nutritious foods, watch several
hours of television daily, and are relatively inactive develop obesity,
the search continues for alternative causes. Heredity has recently been
shown to influence fatness, regional fat distribution, and response to
overfeeding (Bouchard et al., 1990). In addition, infants born to
overweight mothers have been found to be less active and to gain more
weight by age three months when compared with infants of normal weight
mothers, suggesting a possible inborn drive to conserve energy (Roberts,
Savage, Coward, Chew, & Lucas, 1988).
Treatment of Childhood Obesity
Obesity treatment programs for children and adolescents rarely have
weight loss as a goal. Rather, the aim is to slow or halt weight gain so
the child will grow into his or her body weight over a period of months to
years. Dietz (1983) estimates that for every 20 percent excess of ideal
body weight, the child will need one and one-half years of weight
maintenance to attain ideal body weight.
Early and appropriate intervention is particularly valuable. There is
considerable evidence that childhood eating and exercise habits are more
easily modified than adult habits (Wolf, Cohen, Rosenfeld, 1985). Three
forms of intervention include:
- Physical Activity
Adopting a formal exercise program, or simply becoming more active,
is valuable to burn fat, increase energy expenditure, and maintain lost
weight. Most studies of children have not shown exercise to be a
successful strategy for weight loss unless coupled with another
intervention, such as nutrition education or behavior modification (Wolf
et al., 1985). However, exercise has additional health benefits. Even
when children's body weight and fatness did not change following 50
minutes of aerobic exercise three times per week, blood lipid profiles
and blood pressure did improve (Becque, Katch, Rocchini, Marks, &
Moorehead, 1988).
- Diet Management
Fasting or extreme caloric restriction is not advisable for children.
Not only is this approach psychologically stressful, but it may
adversely affect growth and the child's perception of "normal" eating.
Balanced diets with moderate caloric restriction, especially reduced
dietary fat, have been used successfully in treating obesity (Dietz,
1983). Nutrition education may be necessary. Diet management coupled
with exercise is an effective treatment for childhood obesity (Wolf et
al., 1985).
- Behavior Modification
Many behavioral strategies used with adults have been successfully
applied to children and adolescents: self-monitoring and recording food
intake and physical activity, slowing the rate of eating, limiting the
time and place of eating, and using rewards and incentives for desirable
behaviors. Particularly effective are behaviorally based treatments that
include parents (Epstein et al., 1987). Graves, Meyers, and Clark (1988)
used problem-solving exercises in a parent-child behavioral program and
found children in the problem-solving group, but not those in the
behavioral treatment-only group, significantly reduced percent
overweight and maintained reduced weight for six months. Problem-solving
training involved identifying possible weight-control problems and, as a
group, discussing solutions.
Prevention of Childhood Obesity
Obesity is easier to prevent than to treat, and prevention focuses in
large measure on parent education. In infancy, parent education should
center on promotion of breastfeeding, recognition of signals of satiety,
and delayed introduction of solid foods. In early childhood, education
should include proper nutrition, selection of low-fat snacks, good
exercise/activity habits, and monitoring of television viewing. In cases
where preventive measures cannot totally overcome the influence of
hereditary factors, parent education should focus on building self-esteem
and address psychological issues.
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