BUFFALO, N.Y. -- A new study of childhood obesity in the United
States has found that some social factors, such as the presence of
friends, may put overweight youths at greater risk of
The research, published in the August issue of the American
Journal of Clinical Nutrition, demonstrates that friends may
act as "permission givers" on children's food intake.
"These results are important, considering the role of friends as
agents of change in childhood and adolescence," said Sarah Salvy,
Ph.D., assistant professor in the Division of Behavioral Medicine,
Department of Pediatrics, University at Buffalo School of Medicine
and Biomedical Sciences.
"Overweight children are more likely to find food more
reinforcing than non-overweight youth," she continued. "Being in
the company of overweight peers may give them the permission to eat
more or may decrease their inhibitions, increasing what are seen as
the norms of appropriate eating, or how much one should eat."
The study involved 23 overweight and 42 normal weight children
between the ages of 9 and 15, who were randomized to participate
with either a friend or an unfamiliar person of a similar age.
After randomization, there were 33 friend pairs and 39 "unfamiliar"
Before taking part in the study experiment, participants listed
what they had eaten in the past 24 hours to make sure they hadn't
eaten anything during the previous two hours, and rated their
Each participant pair spent 45 minutes in a room equipped with
games, puzzles and individual bowls of low-calorie, "nutrient
dense" baby carrots and grapes, and high-calorie "energy-dense"
potato chips and cookies. The children were told they could eat as
much or as little as they wanted, but were asked to eat from their
own bowls only.
Researchers observed the children via closed-circuit television
and recorded their activities. At the end of the session, they
weighed the snacks that weren't eaten to determine how much each
participant had consumed and to calculate calories.
Results showed that friends who ate together consumed more food
than participants who were paired with someone they didn't know,
and that friends were more likely to eat similar amounts than
participants paired with a stranger.
However, overweight children who were paired with an overweight
peer, whether friend or stranger, ate more than the overweight
participants who were paired with a normal weight youth.
"These findings indicate that both overweight and normal weight
participants eating with a friend ate significantly more than did
participants eating in the presence of an unfamiliar peer," Salvy
said. "These results are consistent with research in adults, which
showed that eating among friends and family is distinctly different
than eating among strangers.
"Given the impact of friends on eating behavior, it appears that
if we hope to change the growing obesity epidemic among children,
friends and family need to be involved," said Salvy. "If the
environment in which children live doesn't change -- if family
meals remain high calorie and overeating is the norm -- any
progress children may make in their eating behavior won't
Salvy currently is investigating the influence of a parent
versus a friend on children's and adolescents' eating behavior.
Marlana Howard and Erica Mele, UB bachelor's degree candidates
who worked with Salvy, and Margaret Read, UB senior research
specialist, also contributed to the study.
The research was supported by a grant to Salvy from the National
Institute of Child Health and Human Development.
The University at Buffalo is a premier research-intensive
public university, a flagship institution in the State University
of New York system and 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 Universities.