title: Intentional weight loss in overweight and obese individuals and cognitive function: a systematic review and meta-analysis.
abstract: High adiposity in middle age is associated with higher dementia risk. The association between weight loss and cognitive function in older adults is still controversial. A meta-analysis was undertaken to estimate the effectiveness of intentional weight loss on cognitive function in overweight and obese adults. A structured strategy was used to search randomized and non-randomized studies reporting the effect of intentional and significant weight loss on cognitive function in overweight and obese subjects. Information on study design, age, nutritional status, weight-loss strategy, weight lost and cognitive testing was extracted. A random-effect meta-analysis was conducted to obtain summary effect estimates for memory and attention-executive domains. Twelve studies met inclusion criteria. Seven were randomized trials and the remaining five included a control group. A low-order significant effect was found for an improvement in cognitive performance with weight loss in memory (effect size 0.13, 95% CI 0.00-0.26, P=0.04) and attention/executive functioning (effect size 0.14, 95% CI 0.01-0.27, P<0.001). Studies were heterogeneous in study design, sample selection, weight-loss intervention and assessment of cognitive function. Weight loss appears to be associated with low-order improvements in executive/attention functioning and memory in obese but not in overweight individuals.
authors.affiliation: Human Nutrition and Physiology, Department of Neuroscience, University of Naples, Naples, Italy. masiervo@yahoo.com
authors.forename: M
authors.initials: M
authors.lastname: Siervo
authors.forename: R
authors.initials: R
authors.lastname: Arnold
authors.forename: J C K
authors.initials: JC
authors.lastname: Wells
authors.forename: A
authors.initials: A
authors.lastname: Tagliabue
authors.forename: A
authors.initials: A
authors.lastname: Colantuoni
authors.forename: E
authors.initials: E
authors.lastname: Albanese
authors.forename: C
authors.initials: C
authors.lastname: Brayne
authors.forename: B C M
authors.initials: BC
authors.lastname: Stephan
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000523:psychology* / Q000628:therapy; D050177:Overweight / Q000523:psychology* / Q000628:therapy; D012307:Risk Factors; D015431:Weight Loss