*Overindulgence may alter brain responses
By JoAnne Allen
WASHINGTON, March 28 Bingeing on high-calorie
foods may be as addictive as cocaine or nicotine, and could
cause compulsive eating and obesity, according to a study
published on Sunday.
The findings in a study of animals cannot be directly
applied to human obesity, but may help in understanding the
condition and in developing therapies to treat it, researchers
wrote in the journal "Nature Neuroscience."
The study, involving rats, found that overconsumption of
high-calorie food can trigger addiction-like responses in the
brain and that high-calorie food can turn rats into compulsive
eaters in a laboratory setting, the article said.
The scientists also found decreased levels of a specific
dopamine receptor -- a brain chemical that allows a feeling of
reward -- in overweight rats, as has been reported in humans
addicted to drugs, the article said.
"Obesity may be a form of compulsive eating. Other
treatments in development for other forms of compulsion, for
example drug addiction, may be very useful for the treatment of
obesity," researcher Paul Kenny of The Scripps Research
Institute in Florida said in a telephone interview.
Obesity-related diseases cost the United States an
estimated $150 billion each year, according to U.S. federal
agencies. An estimated two-thirds of American adults and
one-third of children are obese or overweight.
For the study, Kenny and colleagues headed to the grocery
"We basically bought all of the stuff that people really
like -- Ding-Dongs, cheesecake, bacon, sausage, the stuff that
you enjoy, but you really shouldn't eat too often," he said.
They also bought healthy foods and devised a diet plan for
three groups of rats.
One group ate a balanced healthy diet. Another group
received healthy food, but had access to high-calorie food for
one hour a day. Rats in the third group were fed healthy meals
and given unlimited access to high-calorie foods.
The rats in the third group developed a preference for the
high-calorie food, munched on it all day and quickly became
obese, Kenny said.
The rats in the experiment had also been trained to expect
a minor shock when exposed to a light. But when the rats that
had unlimited access to high-calorie food were shown the light,
they did not respond to the potential danger, Kenny said.
Instead, they continued to eat their snacks.
"What we're seeing in our animals is very similar to what
you'd see in humans who overindulge," he said. "It seemed that
it was okay, from what we could tell, to enjoy snack foods, but
if you repeatedly overindulge, that's where the problem comes