Child Development

genetic contributions to the development of excessive
fatness are better understood, treatment will remain
a process of managing the balance between calorie in-
take and expenditure. This behavioral treatment pro-
cess must support reduction in calorie intake,
modification of food selection, reduction in sedentary
time, and increase in caloric expenditure. Important
components of change include the use of diet diaries,
to help recognize needed diet change, and the careful
replacement of unhealthy food choices with lower cal-
orie items that supply adequate amounts of protein,
carbohydrates, minerals, and vitamins. Similarly, in-
creasing energy expenditure can be the result of re-
ducing reliance on cars, public transportation,
elevators, and other conveniences, while increasing
the time spent walking, bicycling, or other ways of ex-
pending energy, such as using stairs.

Modification of diet and activity and change in
the degree of obesity among children over the age of
eight years can occur in weekly group treatment pro-
grams that also involve parents in separate group ses-
sions. Three treatment program characteristics
contribute most to positive results: comprehensive
treatment (including a combination of behavioral
modification procedures, a special diet, and an exer-
cise program); explicit inclusion of behavior modifi-
cation techniques; and focus on children with more
severe obesity. The diet should emphasize calorie and
fat reduction (tailored to the child’s age and metabol-
ic needs), include a simple categorization of foods un-
derstood easily by children, and be supervised by a
health professional.

More aggressive approaches to weight loss being
used in the treatment of adults are under investiga-
tion in the treatment of adolescents, including the use
of medications, very low calorie diets, and surgery.
Until recently, the use of medications in the treat-
ment of obesity has been of relatively little benefit. In
the late 1990s, success with medications such as
phentermine and fenfluramine, found to decrease
appetite or increase satiety, was tempered by the dis-
covery of unexpected and potentially fatal side ef-
fects. Two newer medications, sibutramine, an
appetite suppressant, and orlistat, a blocker of fat ab-
sorption in the intestine, show promising results in
adult treatment and are undergoing clinical trials for
use in adolescents.

In more extreme situations, caloric intake can be
reduced dramatically with the use of very low calorie
diets and obesity surgery, but should be considered
for adolescents only after completion of puberty.
These diets include anywhere from 300 to 800 calo-
ries per day, primarily as protein and carbohydrate,
and should be instituted only with adequate medical
supervision, since severe nutrient deficiencies and

medical complications, such as fatal rhythm distur-

bances of the heart, can accompany them. Surgical

treatments either reduce the capacity of the stomach,

thereby inducing earlier satiety, or they decrease the

length of the bowel, thereby reducing the bowel’s ca-

pacity to absorb fat from the meal. Significant side ef-

fects in terms of abdominal discomfort, diarrhea, and

potential nutrient deficiency are common.

With the difficulty in treating obesity at any stage

of life, attention is turning toward understanding the

possible role of prevention. Efforts are underway to

develop behavioral and biochemical approaches to

prevention, particularly in children identified as high

risk, based on their early growth patterns and family

history.

See also: EXERCISE; NUTRITION; PHYSICAL GROWTH

Bibliography

Epstein, Leonard H. ‘‘New Developments in Child Obesity.’’ In Al-

bert J. Stunkard and Thomas A. Wadden eds., Obesity. New

York: Raven Press, 1993.

Hammer, Lawrence D. ‘‘The Development of Eating Behavior in

Childhood.’’ Pediatric Clinics of North America 39 (1992):379–

394.

Hammer, Lawrence D., and Thomas N. Robinson. ‘‘Child and Ad-

olescent Obesity.’’ In Melvin D. Levine ed., Developmental-

Behavioral Pediatrics. Philadelphia: Saunders, 1999.

Robinson, Thomas N., and William H. Dietz. ‘‘Weight Gain: Over-

eating to Obesity.’’ In Abraham M. Rudolph ed., Pediatrics.

Stamford, CT: Appleton and Lange, 1996.

World Health Organization. Obesity: Preventing and Managing the

Global Epidemic. Geneva: World Health Organization, 1997.

Lawrence D. Hammer

OBJECT PERMANENCE

Object permanence refers to a set of commonsense

beliefs about the nature, properties, and behavior of

animate and inanimate objects. The first belief is that

objects are permanent entities that exist continuously

and independently of one’s immediate actions on or

perceptions of them. The second and third beliefs

stipulate that objects are stable entities whose proper-

ties and behavior remain subject to physical laws re-

gardless of one’s immediate perception of them.

According to Jean Piaget, a Swiss psychologist who

formulated a major theory of cognitive development,

the understanding that objects exist continuously

emerges during stage four of the sensorimotor period

(around eight months of age), when infants spontane-

ously search for and retrieve an object that they see

being hidden. For Piaget, however, object perma-

nence is not fully developed until the end of the sen-

sorimotor period (around two years of age), when

infants demonstrate through their manual search be-

havior that they can imagine the behavior and motion

of hidden objects.

OBJECT PERMANENCE 289