HBO spotlights one of the most serious threats to the health of Americans in this four-part documentary series on obesity. Three years in the making, "The Weight of the Nation" addresses both the facts and myths of obesity, showing how it affects the health of individuals and strains the health care system. The four documentaries include case studies and interviews with experts from the nation's leading research institutions and with individuals and families struggling with obesity. According to the Centers for Disease Control and Prevention, obesity contributes to six of the 10 leading causes of death in the U.S., including type 2 diabetes, heart disease and high blood pressure.