NEW YORK (Reuters), April
08, 2003
Limiting TV time to no more than 10 hours a week and moderate
exercise, such as 30 minutes a day of brisk walking, can
help adults and children reduce the risk they will become
obese and develop diabetes, one serious disease associated
with obesity.
"The findings are not a surprise to us, but it's
nice to have the scientific data showing the relationship," said
Dr. Frank Hu of the Harvard School of Public Health, whose
study was published in the Journal of the American Medical
Association's special April theme issue on obesity.
"It is very important for individuals to realize
that they are subjected to this hazard without really knowing
it," Hu
said at a news conference in New York.
The study of 50,277 women between 1992 and 1998 found that
adjusted for age, smoking, exercise levels and diet, each
two-hour-per-day increment of TV was associated with a 23
percent increase in obesity and a 14 percent increase in
the risk for type 2 diabetes. This type of diabetes accounts
for 90 percent of all U.S. cases and is related to insulin
resistance, obesity, high cholesterol, and high blood pressure.
An article published in the journal said standing or walking
around at home for two hours a day was associated with a
9 percent reduction in obesity and a 12 percent reduction
in diabetes. Each hour of brisk walking a day saw a 24 percent
reduction in obesity and 34 percent reduction in diabetes.
"We are not talking here about running a marathon
or smashing the television," Hu said.
Men spend about 29 hours per week watching TV and women spend
about 34 hours per week, according to a 1997 U.S. survey.
Compared with other sedentary activities, like computer work,
board games or driving a car, TV watching results in a lower
metabolic rate.
A person with a body mass index, called BMI, (a person's
weight in kilograms divided by height in meters squared)
of more than 30 is considered obese. "The more time
spent in front of the TV, the higher the BMI," Hu said.
CHILD OBESITY
The researchers said that long hours of watching TV was also
associated with obesity in children.
I
n a separate commentary, obesity expert Dr. Susan Yanovski
of the National Institutes of Health told reporters that
the proportion of children and adolescents who are overweight
has tripled since the 1960s and was a worldwide problem.
Obesity had been found to predispose children and adolescents
to medical complications found in adults, including hypertension,
type 2 diabetes, liver disorders and sleep apnea, she said.
Harvard's Hu said corporations that sell fast foods, the
food industry as a whole and government policy had a role
to play in preventing obesity.
"The McDonalds, the Burger Kings have tremendous
impact on kids. There should be some balance between promoting
fast
foods and promoting healthy activity and healthy food messages."
The journal also reported that new analysis of low-carbohydrate
diets -- such as the popular one promoted by Dr. Robert Atkins
-- found there was "insufficient evidence to make recommendations
for or against the use of these diets."
In an editorial, George Bray of Louisiana State University
in Baton Rouge said: "Obesity is a worldwide epidemic
that will be followed by a worldwide epidemic of diabetes.
... The issue of whether a unique diet exists that will produce
long-term weight loss has yet to be evaluated."
© Copyright
Reuters 2002
