Reduction of anxiety after restricted feeding in the rat: implication for eating disorders.
BACKGROUND
Eating-disorder patients exhibit not only abnormal eating attitudes but also pathologic anxiety-like behaviors. The specific nature of the relationship between dieting and anxiety-like behavior is unknown.


METHODS
To investigate the adaptational changes that resulted from chronic restricted scheduled feeding (2-hour access per day for 2 weeks) and subsequent free refeeding, longitudinal changes in the microstructure of feeding behavior were studied in male rats. To study the relationship between restricted feeding and anxiety-like behavior, separate rats were tested in the elevated plus-maze under the following conditions: 1) free feeding; 2) acute food restriction (2-hour access for 1 day); 3) chronic food restriction (for 10 days); or 4) postrecovery (after 10 days of free feeding subsequent to chronic food restriction).


RESULTS
The effects of chronic food restriction on meal structure diminished within a few days after refeeding. Decreased anxiety-like behavior was seen during acute and chronic food restriction and did not reflect nonspecific behavioral activation. Anxiolytic-like effects persisted after 10 days of refeeding.


CONCLUSIONS
Chronic food restriction produced reductions in anxiety-like behavior that persisted beyond the normalization of food intake patterns. The findings might have etiologic and pathophysiologic relevance for the restrained eating pattern in eating-disorder patients with comorbid anxious symptoms.
Inoue
Koki
K
Department of Neuropharmacology, The Scripps Research Institute, La Jolla, California, USA.
Zorrilla
Eric P
EP
Tabarin
Antoine
A
Valdez
Glenn R
GR
Iwasaki
Sinichi
S
Kiriike
Nobuo
N
Koob
George F
GF
D000223:Adaptation, Psychological / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000209:etiology / Q000628:therapy*; D001835:Body Weight; D004195:Disease Models, Animal; D004326:Drinking; D004327:Drinking Behavior; D004435:Eating; D005247:Feeding Behavior / Q000502:physiology*; D001068:Feeding and Eating Disorders / Q000150:complications*; D005502:Food; D005508:Food Deprivation; D008297:Male; D018782:Maze Learning / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar