Obesity and its complications, including nonalcoholic fatty liver disease (NAFLD), have reached epidemic proportions, affecting over a quarter of the world’s population. Even in our current obesogenic environment however, some people do not develop obesity and not all individuals with obesity develop complications related to their obesity, such as NAFLD. The propensity to become obese or develop NAFLD is partially heritable or genetic and our group has already helped identify many genetic variants that predispose individuals to developing obesity and NAFLD. Some of these variants predispose to multiple metabolic diseases whereas others do not helping to partially explain why some people will develop some but not other complications of obesity. Our group aims to further define the genetic and environmental influences that predispose individuals to obesity and NAFLD and translate that information into better ways to diagnose, manage, and treat these conditions in the future.