Obesity and genetics.

Genetics is now known to play a substantial role in the predisposition to obesity and may contribute up to 70% risk for the disease. Over a hundred genes and gene variants related to excess weight have been discovered. Yet, genetic obesity risk does not always translate into actual obesity development, suggesting complex interactions between genetic, behavioral, and environmental influences and resulting epigenetic changes. Rare but serious forms of monogenic obesity typically appear in early childhood. Polygenic obesity is most common and demonstrates strong interplay between genes and the obesogenic environment. This review provides an overview of genetic causes of obesity, potential mechanisms of epigenetic changes, and environmental influences that should diminish obesity bias and offer hope for more effective obesity prevention and intervention strategies.