Obesity is a heritable trait that contributes to substantial global morbidity and mortality. Here, we summarize findings from the last decade of genetic and epigenetic research focused on unravelling the underpinnings of adiposity. More than 140 genetic regions are now known to influence adiposity traits. The genetics of general adiposity, as measured by body mass index, and that of abdominal obesity, as measured by waist to hip ratio, have distinct biological backgrounds. Expression of genes associated with general adiposity are enriched in the nervous system.