Lack of effect of short-term fasting on cognitive function

Green, Michael W.; Elliman, Nicola A.; Rogers, Peter J.

doi:10.1016/0022-3956(95)00009-t

Cited by 72 publications

(67 citation statements)

References 14 publications

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“…Cognitive function was measured using a computerized task battery that measures multiple modalities of cognitive performance (Green et al, 1995b). These included sustained attention (Bakan vigilance task), short-term memory (word recall task), simple reaction time, motor performance (two ®nger tapping task), and focused attention (Ericksen effect).…”

Section: Methodsmentioning

confidence: 99%

Cognitive function, iron status, and hemoglobin concentration in obese dieting women

et al. 1998

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Objective: To determine the relationships between cognitive function and iron status in dieting obese women. Design: 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. Dietary iron was fed at twice the US Recommended Dietary Allowance with half of the iron from food sources and half from an oral supplement. Setting: This was a free-living study with the exception that subjects came to the research center for one meal per day and were provided all other meals and snacks to take home. Subjects: Healthy, premenopausal, obese women (mean BMI 31.5) were recruited through local newspaper, poster and radio advertising. Twenty-four women volunteers were recruited and 14 completed the study. Measurements: Cognitive function, iron and hematological status, height, body weights and body composition were measured at baseline; at weeks 5, 10, and 15 of the energy restriction period; and at the end of weight stabilization. Computerized cognitive tests included: Bakan vigilance task, two ®nger tapping, simple reaction time, immediate word recall, and a focused attention task. Iron status and hematological measures included: serum iron, total iron binding capacity (TIBC), transferrin saturation, serum ferritin, hemoglobin (Hb), hematocrit, red cell count, MCV, MCH, MCHC, and RDW. Results: A signi®cant reduction in Hb, hematocrit, and red blood cell count occurred across the study. Hb at the end of the study was positively correlated (r = 0.72, P < 0.01) with mean performance on a measure of sustained attention. Transferrin saturation also correlated positively to sustained attention task performance for those subjects whose Hb declined across the study (r = 0.86, P < 0.01). Conclusions: These ®ndings suggest that dieting diminishes iron status in obese women, even when suf®cient dietary iron is available, and that the inability to sustain attention may be an early sign of developing iron de®ciency in dieting women.

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Section: Methodsmentioning

confidence: 99%

Cognitive function, iron status, and hemoglobin concentration in obese dieting women

et al. 1998

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“…24 Cognitive function was measured using a computerized task battery that measures multiple modalities of cognitive performance. 4 These included sustained attention (Bakan vigilance task), short-term memory (word recall task), simple reaction time, motor performance (two ®nger tapping task), and focused attention (Ericksen effect); always administered in this order. Subjects were scheduled for the same time each session, between 8:30 am and 11:30 am, and testing lasted about 45 minutes.…”

Section: Measurementsmentioning

confidence: 99%

“…10 For instance, mild degrees of food restriction per se have been reported to exert either small detrimental effects, 11,12 small bene®cial effects, 11 or no effects at all on cognitive processing. 4 Such work reveals a complex interaction between the meal missed (lunch or breakfast), circadian variation, practice and/or fatigue effects and the domain of cognitive function.…”

Section: Introductionmentioning

confidence: 99%

Cognitive effects of a long-term weight reducing diet

et al. 1997

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OBJECTIVE: To investigate if long-term caloric restriction under controlled conditions adversely affects cognitive function in obese women. SUBJECTS: Healthy, premenopausal women between 23±42 y. Dieting group: n 14. Control group: n 11. DESIGN: 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. MEASUREMENTS: 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 AE 5.5 kg (mean AE s.d.) of body weight. Controlled long-term caloric restriction signi®cantly slowed simple reaction time but did not diminish sustained attention, motor performance or immediate memory. Word recall performance signi®cantly 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.

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“…There was a significant threeway interaction between test session, participant group and trial block (F (16,72) ¼ 2·041, P ¼ 0·022). Post hoc analysis revealed that, while reaction times generally increased over the course of each test session (consistent with a fatigue effect), this effect was significantly larger for the unsupported dieters in the second test session (P , 0·05).…”

Section: Cognitive Functionmentioning

confidence: 99%

Are dieting-related cognitive impairments a function of iron status?

Green

Elliman

2012

Br J Nutr

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The aim of the present study was to investigate whether the impairments in cognitive function observed in unsupported dieting are related to compromised Fe status. During a non-clinical intervention, overweight participants (age: 18 -45 years, BMI: 25-30 kg/m 2 ) either participated in a commercially available weight-loss regimen (n 14), dieted without support (n 17) or acted as a non-dieting control group (n 14) for a period of 8 weeks. Measurements of cognitive function and blood chemistry were taken at a pre-diet baseline, after 1 week and 8 weeks of dieting. After 1 week, unsupported dieters displayed impaired verbal memory, executive function and slower reaction speeds than the other two groups, this difference disappearing by the end of the study. There were no significant group-related changes in blood chemistry over the course of the study, although there were group-related changes in a number of self-reported food-related cognitions. In conclusion, impaired cognition among unsupported dieters is not due to compromised Fe status and is most likely to result from psychological variables. Key words: Dieting: Dietary support: Cognition: Iron metabolismDeliberate restriction of food intake to control weight is one of the most common food choice-related behaviour in the developed world. Indeed, over one-third of the general US population is classed as obese (1) , with an associated impact on health treatment resources (2) . Within the context of these rising obesity rates (3) , an understanding of the psychological impact of undernutrition and weight loss assumes an increasing importance.While there are undoubted health benefits of controlling obesity, the attempt to lose weight by dieting has been associated with a number of negative psychological consequences such as increased depression and low self-esteem (4) . Although the evidence concerning the psychological effects of experimentally induced weight loss is equivocal (5) , evidence suggests that dieting is reliably associated with a range of impairments in cognitive function. For instance, dieting has been associated with slower reaction speed, impaired verbal memory and an impaired ability to sustain attention (6,7) . A number of studies have indicated that this pattern of impaired task performance is primarily due to a reduction in available working memory capacity (8 -11) , which is primarily due to preoccupying cognitions relating to hunger (8) and body shape-related self-esteem (12,13) . This is important, since working memory is the primary cognitive domain, controlling moment-to-moment rules of action, planning ability and the short-term retention of information. The most commonly accepted model of working memory (14) proposes a tripartite system comprising a phonological loop (controlling verbal short-term memory), a visuospatial sketchpad (controlling visual memory) and an overarching supervisory system known as the 'central executive'.It has also been found that the way in which weight loss is attempted influences cognitive function, ...

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Lack of effect of short-term fasting on cognitive function

Cited by 72 publications

References 14 publications

Cognitive function, iron status, and hemoglobin concentration in obese dieting women

Cognitive function, iron status, and hemoglobin concentration in obese dieting women

Cognitive effects of a long-term weight reducing diet

Are dieting-related cognitive impairments a function of iron status?

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