MAPT and obesity due to melanocortin 4 receptor deficiency: Obesity has been shown to double the risk of Alzheimer’s disease (Anstey et al., 2011; Pedditzi et al., 2016), with postmortem studies of obese elderly individuals showing increased concentrations of amyloid-beta and hyperphosphorylated tau, which were associated with hippocampal atrophy (Mrak, 2009).