MTOR and Alzheimer disease: As obesity is a well-known factor for AD pathogenesis [139] and overeating results in insulin resistance and mTOR activation [140], caloric restriction is a well-documented remedy to mitigate the aging process by reducing the concentration of glucose, lipids, and amino acids and increasing some metabolites such as NAD+ and AMP which modulate SIRT1, AMPK, mTOR, and IGF1 activities.