REN and Obesity: Thus, in brain, hyperinsulinemia increases Aβ‐plaque precursors and Alzheimer risk; in kidney, hyperinsulinemia activates the renin–angiotensin–adrenal axis, thus increasing vasoconstriction, sodium retention, and cardiovascular risk; and in liver, hyperinsulinemia increases lipogenesis, obesity, hepatosteatosis, hyperlipidemia, and cardiovascular risk.