Activation of AMPK turns on ATP-generating processes, while switching off ATP-consuming processes. In skeletal muscle, acute activation of AMPK increases glucose uptake and lipid oxidation, while chronic activation of AMPK is associated with mitochondrial biogenesis. Activation of AMPK inhibits glucose and lipid synthesis in the liver but increases lipid oxidation. Lipolysis and lipogenesis in adipose tissue are also reduced by AMPK activation. Collectively, activation of AMPK in skeletal muscle, liver, and adipose tissue results in a favorable metabolic milieu for the prevention or treatment of T2D, i.e., decreased circulating glucose, reduced plasma lipid, and ectopic fat accumulation, as well as enhanced insulin sensitivity. Activation of pancreatic AMPK is associated with decreased insulin secretion, likely a protective measure to prevent hypoglycemia during food deprivation, although this effect needs to be considered in pharmaceutical targeting of AMPK for the treatment of T2D.