The results obtained suggest a protective effect induced by HFD on learning of AD‐like mice, through a mechanism that involved better barrier properties and brain morphology (normal ventricle volume), higher insulin receptor RNA expression in the hippocampus, and higher HDL cholesterol, but not through reduction in amyloid beta 1–42 (Aβ1‐42) levels. The gene discussed is INSR; the disease is Alzheimer disease.