Effects of dietary fat manipulation on cognition in mice and rats:protocol for a systematic review and meta-analysis

INTRODUCTION AND OBJECTIVE: The Western diet that comprises high levels of long-chain saturated fats and sugar is associated not only with metabolic disorders such as obesity and type 2 diabetes but also has been recently linked to brain changes and cognitive dysfunction. However, in animal studies, reported effects are variable, and the mechanisms underlying these effects are unclear. In the proposed review, we aim to summarise the diverse evidence of the effects of so-called ‘high-fat’ and ketogenic diets on behavioural measures of cognition in postweaning mice and rats, relative to animals on standard diets and to determine potential underlying mechanisms of high-fat diet-induced effects. SEARCH STRATEGY: A comprehensive search strategy was designed to retrieve studies reporting use of a high-fat or ketogenic diet in postweaning mice and rats that included cognitive assessments. Three databases (Medline, SCOPUS and Web of Science) were searched and 4487 unique references were retrieved. SCREENING AND ANNOTATION: Studies were screened for inclusion by two independent reviewers, with 330 studies retained for analysis. Characteristics of disease model choice, experimental design, intervention use and outcome assessment are to be extracted using the Systematic Review Facility (http://syrf.org.uk/) tool. Studies will be assessed for study quality and risk of bias and confidence of mechanistic involvement. DATA MANAGEMENT AND REPORTING: For cognitive outcomes, effect sizes will be calculated using normalised mean difference and summarised using a random effects model. The contribution of potential sources of heterogeneity to the observed effects of diet on cognition will be assessed using multivariable meta-regression, with partitioning of heterogeneity as a sensitivity analysis. A preliminary version of this protocol was published on 9 April 2019 on the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies website (http://www.dcn.ed.ac.uk/camarades/research.html%23protocols). ETHICS AND DISSEMINATION: No ethical approval is required as there are no subjects in the proposed study

A high-fat diet induces rapid changes in the mouse hypothalamic proteome

Funding LMW, FMC, CG, ACM and C-DM were funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS). FHM was supported by an EASTBIO DTP BBSRC studentship. DS was supported by a SULSA studentship. CR was supported by the HOTSTART Scholarship Programme from the School of Medicine, Medical Sciences and Nutrition, University of Aberdeen. Availability of data and materials All data generated or analysed during this study are included in this published article [and its Supplementary information files].Peer reviewedPublisher PD

Rapid and reversible impairment of episodic memory by a high-fat diet in mice.

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. This work was supported by an EASTBIO BBSRC PhD studentship to F.H.M., L.M.W., C.G., A.C.M., G.W.H. and F.M.C. are supported by Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS).Peer reviewedPublisher PD

Early and reversible changes to the hippocampal proteome in mice on a high-fat diet

Funding LMW, FMC, CG, ACM and C-DM were funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS). FHM was supported by an EASTBIO DTP BBSRC studentship. DS was supported by a SULSA studentship.Peer reviewedPublisher PD