How obesity develops: insights from the new biology.

Molecular and genetic studies of animal models have identified numerous genes that may cause or contribute to the development of obesity. They have also provided significant insight into the peripheral and central pathways that control energy intake and expenditure. Genetic studies of families and populations have generated useful information on genes and mutations associated with or linked to obesity, body fat distribution, and other relevant phenotypes. This information, combined with knowledge of the chromosomal location of genes identified from animal studies, has made it possible to identify specific mutations that contribute to the development of obesity in humans.