Some experimental studies support the notion that HFD‐induced obesity exacerbates cerebral pathological alterations and the accompanying cognitive deficit in APP transgenic mice (Ho et al., 2004) while other claim for no effect (Kesby et al., 2015) or even improvement of memory in mice (Coscina, Yehuda, Dixon, Kish, & Leprohon‐Greenwood, 1986). The gene discussed is APP; the disease is obesity due to melanocortin 4 receptor deficiency.