BUFFALO, N.Y. -- Entrenched sedentary behavior such as watching
television and playing computer video games has been the bane for
years of parents of overweight children and physicians trying to
help those children lose pounds.
There has been little scientifically based research on the
effect of limiting those activities, however.
University at Buffalo researchers now have shown in a randomized
trial that by using a device that automatically restricted
video-viewing time, parents reduced their children's video time by
an average of 17.5 hours a week and lowered their body-mass index
(BMI) significantly by the end of the 2-year study.
In contrast, children in the control group, whose video time was
monitored, but not restricted, reduced their viewing time by only 5
hours per week.
Results of the study appear in the current issue (March 2008) of
the Archives of Pediatric & Adolescent Medicine.
"Our controlled experiment provided a test of whether reducing
access to television and computer time led to a reduction in BMI,"
said Leonard Epstein, UB Distinguished Professor in the departments
of Pediatrics, Health Behavior and Social and Preventive Medicine
and first author on the study.
"Results showed that watching television and playing computer
games can lead to obesity by reducing the amount of time that
children are physically active, or by increasing the amount of food
they consume as they as engaged in these sedentary behaviors."
The study involved 70 boys and girls between the ages of 4 and 7
whose BMI -- the ratio of weight to height -- was at or above the
75 percentile for age and sex. Eighty percent of the children were
above the 85th percentile and nearly half were above the 95th
The children were assigned randomly to a control group or an
intervention group. Each family received a device called TV
Allowance for all video outlets in the home. All participants
regularly watched television or played computer video games for at
least 14 hours per week, as determined during a 3-week pre-study
Each family member had a private individual code to activate the
electronic devices. Devices in "intervention" homes, but not
"control" homes, had a set weekly time limit, which was reduced by
10 percent per week until viewing time was reduced by 50 percent.
Children had to decide how to "spend" their allotted viewing
Body mass index, caloric intake and physical activity were
monitored every six months. Data were collected on socioeconomic
status and characteristics of the neighborhood, including distance
to parks, neighborhood activities and perceived neighborhood
Changes in BMI between groups were statistically significant at
6 months and 12 months, but became more modest over time, results
showed. The intervention group showed a steady decline in BMI over
the two years, while the control group showed an increase followed
by a steady decline.
"Although the changes overall were modest," commented Epstein,
"a small effect of using this simple and inexpensive intervention
[the device costs approximately $100], magnified across the
population, may produce important reductions in obesity and
obesity-related health problems."
Also contributing to the study from UB were James N. Roemmich,
Ph.D., associate professor of pediatrics and exercise and nutrition
sciences; Jodie L. Robinson, MBA, senior counselor in the
Behavioral Medicine Laboratory; Rocco A. Paluch, statistician in
the UB Department of Pediatrics; Dana D. Winiewicz, senior research
support specialist in pediatrics; and Janene H. Fuerch, student
assistant. Thomas N. Robinson, M.D., M.P.H., from Stanford
University School of Medicine in Stanford, Calif., also contributed
to the study.
The research was supported by a grant from the National
Institute of Diabetes and Digestive Diseases to Epstein and by the
UB Behavioral Medicine Laboratory in the UB School of Medicine.
The University at Buffalo is a premier research-intensive
public university, a flagship institution in the State University
of New York system that is its largest and most comprehensive
campus. UB's more than 28,000 students pursue their academic
interests through more than 300 undergraduate, graduate and
professional degree programs. Founded in 1846, the University at
Buffalo is a member of the Association of American