To limit its overactivation, mTOR blocks insulin signaling, causing IR.34, 35, 36, 37, 38, 39 Rapamycin and calorie restriction (CR) can reverse IR.32, 34, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 For example, in healthy men, infusion of amino acids activates mTOR causing IR.44, 46 Administration of 6 mg rapamycin before amino acids prevents IR.46 Noteworthy, IR and metabolic syndrome are multifactorial.50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61. Here, MTOR is linked to metabolic syndrome.