An incre asing prevalence of obesity has led to an increase in the incidence of sleep disordered breathing in the general population. Obesity is associated with anatomic alterations that predispose to upper airway obstruction during sleep, leading to complete or partial cessation of respiration called obstructive sleep apnea. The awareness of this global issue is rising, and health care systems are providing preventive measures, diagnostic, and treatment options for both conditions. To decrease obesity, lifestyle modification (eating behaviors, smoking, drinking alcohol, etc.) and understanding the importance of exercise are needed. If these lifestyle modifications are widely applied, then not only obesity and sleep apnea will be reduced but also the incidence of serious consequences such as cardiovascular disease and health care costs will decrease greatly.