Studies on the effects of HFDs on cognition in non-APOE mice showed spatial memory deficits and deficits in other cognitive task including novel object recognition and fear condoning in wild type mouse models (Hwang et al., 2010; Kesby et al., 2015) and AD mouse models (Barron et al., 2013; Knight et al., 2014; Kesby et al., 2015; Lin et al., 2016; Johnson et al., 2017). Here, APOE is linked to Alzheimer disease.