Given that 3xTg‐AD mice exhibit both tau and Aβ accumulation in the brain, we explored the mechanisms underlying the exacerbation of the AD phenotype due to HFD by quantifying total tau, phosphorylated tau at Thr181 (AT270), T212/S214, full‐length APP (Fl‐APP), and C‐terminal fragments (CTF‐α/β). This evidence concerns the gene APP and Alzheimer disease.