Diet Foods May Promote Child Obesity
Rat Research Links Low-Calorie Foods to Overeating
WebMD News Archive
Aug. 8, 2007 -- Diet sodas and other noncalorie and low-calorie foods may be
contributing to the childhood obesity epidemic, new research suggests.
The studies involved young rats, not children, but researchers say the
findings indicate that eating diet foods early in life may inadvertently lead
to overeating and obesity later on.
Juvenile rats in the study fed sweet or salty low-calorie foods over time
later overate when fed similar tasting calorie-dense foods, suggesting that the
low-calorie foods disrupted the body's ability to recognize calories and
regulate energy intake.
This was especially true among young rats genetically predisposed to become
Researcher W. David Pierce, PhD, acknowledges that extrapolating the
findings to human children is a big leap.
But the University of Alberta sociology professor says the rat studies may
provide important clues about how early taste conditioning leads to overeating
"Our findings suggest that in young children, diet foods may be a poor
substitute for healthy foods with sufficient calories to meet energy
needs," he tells WebMD.
Diet Foods and Obesity
The experiments involved 4-week-old juvenile and 8-week-old adolescent rats
conditioned to associate particular tastes with caloric content.
This was done by feeding the animals either sweet or salty high-calorie or
low-calorie gelatin cubes over the course of 16 days.
When the juvenile rats were later given energy-dense, pre-meal snacks with
the same flavor as the low-calorie cubes, they ended up eating more regular
food at meal time.
This was not the case with the older rats.
The study is published in the August issue of the journal
The findings may help explain previous studies suggesting a link between
diet soda consumption and obesity in children, Pierce and colleagues
"Data from our study indicate that the subversion of the relationship
between taste and caloric content disrupts the normal physiological and
behavioral energy balance of juvenile rats, resulting in overeating that is
independent of genetic disposition for obesity," they wrote.
The American Beverage Association has said on multiple occasions that soft
drinks and diet soft drinks do not cause weight gain. "All of our
industry's beverages -- including regular or diet soft drinks -- can be part of
a healthy way of life when consumed in moderation and as a part of a balanced
lifestyle," they note in news statements.
Diet Expert Weighs In
Childhood obesity expert Goutham Rao, MD, says the rat studies may or may
not give insights into how hunger cues relate to energy intake in young
Rao, the author of the book, Child Obesity: A Parent’s Guide to a Fit,
Trim and Happy Child, does agree that eating a healthy, well-balanced diet
is better for young children than eating processed diet foods.
Rao directs the Center for Weight Management and Wellness at Children’s
Hospital of Pittsburgh.
"Parents often ask me if their children should drink diet sodas," he
tells WebMD. “I tell them that diet soda is better than regular soda, but my
preference would be water or low-fat milk."
He says soft drinks sweetened with sugar and other sugary beverages are
among the biggest contributors to childhood obesity in the U.S.
"The solution to the obesity epidemic is simple to understand but hard
to implement," he says. "Avoid sweetened beverages, avoid fast food,
limit media time, fit physical activity into the everyday routine, and eat
together as a family. If every family did these things there would be very few
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