Binge eating boosts gastric capacity, initiating cycle. (A Circular Process).
"It looks like the stomach has a mind of its own," said Dr. Geliebter of the Obesity Research Center at St. Lukes-Roosevelt Hospital Center, New York.
Dr. Geliebter described a series of studies designed to assess the gastric capacity of normal-weight and obese individuals and those with eating disorders. In one, a balloon was lowered into the stomach and inflated until the point of maximum discomfort or a pressure rise of 5 cm/[H.sub.2]O. Obese individuals could tolerate a much larger volume than those of normal weight, suggesting increased gastric capacity.
A comparable increase in gastric capacity was observed in normal-weight bulimic subjects, he said.
Findings were similar when subjects were instructed to consume a liquid or a normal meal until they felt "extremely" full.
Bulimic individuals consumed significantly more than controls, and there was a strong correlation between the size of the test meal consumed and gastric capacity as determined by balloon inflation.
The size of a typical binge (based on food records and recall) also closely correlated with gastric size, he said.
The findings were similar in individuals with binge-eating disorder (BED): Gastric capacity was greater than in normal controls (by both subjective and objective criteria) and was associated with the lifetime number of binges.
The more frequently subjects hinged and the longer they had been doing it, the larger their gastric capacity, Dr. Geliebter observed.
"It's a circular process," Dr. Geliebter said. "Bingeing leads to larger gastric capacity, which means less satiety at a given food intake, and this leads to further binges."
Measures of cholecystokinin, a peptide associated with satiety, reflected the same process. After a fixed meal, levels were lower in bulimic subjects than in controls, he said.
Individuals with BED also appear to differ in stress response. Stress is a known trigger of binge eating, and those with BED report higher levels of global stress than do controls.
When subjected to the cold pressor test, an experimental stressor, individuals with and without BED reported comparable subjective stress, Dr. Geliebter said at the conference.
But diastolic blood pressure rose significantly more in those with BED than in those without BED, as did cortisol. The rise in cortisol was associated with the desire to binge, Dr. Geliebter said.
These findings suggest that individuals with BED should be encouraged to consume small, frequent meals, and to avoid concentrating their food consumption at night.
Relaxation and stress reduction techniques might reduce the incidence of triggers for binge eating, he said.
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|Publication:||Clinical Psychiatry News|
|Date:||Nov 1, 2002|
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