LEP and hydrops fetalis: We measured the ability of exogenous leptin to activate the long-form of the leptin receptor in 23 distinct brain regions in 4 different groups of mice: mice fed a control diet (10% calories from fat) ad libitum (LF); mice fed HFD (60% calories from fat) ad libitum (HF); mice fed HFD ad libitum followed by a period of caloric restriction (CR); and mice fed HFD and then switched back to control diet (LF-HF).