Book excerpt: This book provides a comprehensive compilation of the evidence available regarding the role of genetic differences in the etiology of human obesities and their health and metabolic implications. It also identifies the most promising research areas, methods, and strategies for use in future efforts to understand the genetic basis of obesities and their consequences on human health. Leading researchers in their respective fields present contributed chapters on such topics as etiology and the prevalence of obesities, nongenetic determinants of obesity and fat topography, and animal models and molecular biological technology used to delineate the genetic basis of human obesities. A major portion of the book is devoted to human genetic research and clinical observations encompassing adoption studies, twin studies, family studies, single gene effects, temporal trends and etiology heterogeneity, energy intake and food preference, energy expenditure, and susceptibility to metabolic derangements in the obese state. Future directions of research in the field are covered in the book as well.