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A study suggested that eating habits might not be as complicated
as once thought.
In March, the Centers for Disease Control made the announcement
that the second leading cause of death in the United States was
obesity. On average, 64 percent of U.S. adults who were aged 20
years and over were considered either obese or overweight, with
a body mass index (BMI) that exceeded 25.
In the movie, "Super Size Me," filmmaker Morgan Spurlock
gorged on solely fast food for one month and endangered his liver
in the process. While the intentions behind the film were supposed
to provide insight and entertainment, the American Council on Science
and Health, a consumer institution that focuses on nutrition and
health issues, stated the movie downplayed the seriousness of the
obesity epidemic.
They also claimed the film placed all the blame on the fast food
industry, rather than on individual responsibility.
Experts said that untreated obesity led to higher risks of heart
disease, diabetes and stroke. Through the discovery of leptin, a
hormone found in fat tissue, scientists have gained a better understanding
of obesity at the molecular level.
A research team discovered that leptin changed the physical structure
and functions of the brain, particularly the hypothalamus.
In a study, the feeding activity and the brain functions were observed
of normal weight mice and obese mice that were void of the leptin
hormone. When the larger mice were given leptin, two specific neurons
were affected. One of the neurons called the neuropeptide Y (NPY)
awakened the food intake reactor and caused body weight to increase.
The other neuron, proopiomelanocortin (POMC), produced the opposite
effect.
Researchers believed that these changes would alter the eating
habits of the animals due to the response of POMC when leptin was
present and overeating that occurred when leptin was absent. Researchers
also stated that leptin acted as a signal to the animal that it
was full.
Results from the study on mice have raised the possibilities of
testing the effects of leptin in obese people. The results also
raised questions regarding the differences of brain wiring in obese
and lean people and whether or not it could provide an explanation
as to why people were obese or lean.
Until testing is performed on humans, researchers have recommended
that issues such as diet, food availability, exercise and nutrition
should be addressed as a way to find out about the impact of foods
on the hormone levels and risk of disease.
Science
Central May 18, 2004
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