Cognitive effects of a long-term weight reducing diet.
OBJECTIVE
To investigate if long-term caloric restriction under controlled conditions adversely affects cognitive function in obese women.


METHODS
Healthy, premenopausal women between 23-42 y. Dieting group: n = 14.


METHODS
n = 11.


METHODS
Longitudinal weight loss study (repeated measures within-subject design) with 3 weeks of baseline, 15 weeks of 50% caloric restriction, and 3 weeks of weight stabilization.


METHODS
Computerized cognitive function tests (sustained attention, short-term memory, simple reaction time, motor performance and attentional focus), height, body weight, body composition (TOBEC) and behavioral questionnaires (Dutch Eating Behaviour Questionnaire, Eating Attitudes Test, and State-Trait Anxiety Inventory).


RESULTS
Dieting women lost 12.3 +/- 5.5 kg (mean +/- s.d.) of body weight. Controlled long-term caloric restriction significantly slowed simple reaction time but did not diminish sustained attention, motor performance or immediate memory. Word recall performance significantly improved by 24% at the end of caloric restriction.


CONCLUSIONS
The slowing of simple reaction time is a short-term and long-term consequence of caloric restriction. In contrast to previous short-term dieting studies, sustained attention and immediate memory were not impaired with long-term caloric restriction.
Kretsch
M J
MJ
U.S. Department of Agricultural, Agriculture Research Service, Western Human Nutrition Research Center, Presidio of San Francisco, California 94129, USA.
Green
M W
MW
Fong
A K
AK
Elliman
N A
NA
Johnson
H L
HL
D000328:Adult; D001824:Body Constitution / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D004038:Diet, Reducing / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D009765:Obesity / Q000178:diet therapy* / Q000503:physiopathology; D018579:Patient Selection; D011930:Reaction Time / Q000502:physiology; D011795:Surveys and Questionnaires; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology*