Soft Drink Sweetener May Add Extra Fat
Fructose May Alter Metabolism to Add Body Fat
July 29, 2005 -- A sweetener commonly used in soft drinks and other foods
may lead to more body fat than drinks sweetened with plain sugar.
A new study suggests that fructose may alter the body's metabolism in a way
that prompts it to store body fat.
Researchers say the findings may help explain the recently established link
between rising soft drink popularity and obesity rates in the U.S. and other
parts of the world.
"Our study shows how fat mass increases as a direct consequence of soft
drink consumption," says researcher Matthias Tschöp, MD, associate
professor of psychiatry at the University of Cincinnati, in a news release.
Fructose is a sweetener found naturally in fruits and honey and is widely
used as a sweetener in soft drinks, fruit juices, and cereal. In soft drinks,
fructose is usually found in the form of high-fructose corn syrup, which
contains 55% fructose.
Fructose: Stealth Fat Builder?
In the study, researchers compared the effects of feeding mice
fructose-sweetened water, a soft drink sweetened with sucrose (table sugar), a
diet soft drink, or water. The mice were allowed to drink as much as they
wanted of their designated beverage.
The mice that drank the fructose-sweetened water gained significantly more
body fat than the others, even though they decreased the amount of calories
they ate from solid food.
"We were surprised to see that mice actually ate less when exposed to
fructose-sweetened beverages, and therefore didn't consume more overall
calories," says Tschöp. "Nevertheless, they gained significantly more
body fat within a few weeks."
More Weight, More Body Fat
All of the mice weighed about 39 grams at the start of the study. Those that
drank the fructose-sweetened water gained an average of 8 grams during the
course of the study compared with average weight gains of less than 5 grams
among the others.
The fructose-drinking mice also gained more body fat. Body fat increased by
nearly 11% in the fructose group of mice -- significantly more than the 5%
increase in the water group. Body fat increased by 7% to 8% in the soft drink
and diet soft drink groups.
Researchers say the results suggest that the body metabolizes fructose
differently than other sweeteners or carbohydrates and in a way that favors fat
Their findings appear in the current issue of Obesity Research.
A 2004 report showed that
and that the figure is
closer to 300 calories for the top 20% of Americans.
WebMD spoke to study researcher George A. Bray when that study was released.
Bray said between 1970 and 1990, high-fructose corn syrup consumption increased
by more than 1,000%, largely because the nation's soft drink manufacturers
switched from sucrose to high-fructose corn syrup.