Background: Obstructive sleep apnea (OSA) is a condition characterized by repeated episodes of partial or complete obstruction of the respiratory passages during sleep. The body's response to obstructed breathing leads to arousal of the brain, sympathetic activation, and disturbances in gas exchange leading to oxygen desaturation, hypercapnia, and sleep fragmentation. Abnormal upper airway anatomy, resulting in smaller cross sectional area, is an important factor contributing to OSA (Chen et al., 2016). In addition to decreased cross-sectional area, differences in the shape and length of the upper airway are evident. An increased antero-posterior dimension decreases the efficiency of upper airway dilator muscles. Increased upper airway length contributes to its collapsibility. Increased fat deposit around the pharynx is regarded as a key mechanism through which obesity results in OSA. Peri-pharyngeal fat deposition can produce an extra-mechanical load that can prevent dilator muscles from keeping the airway patency. Through weight loss, nasopharyngeal collapsibility can be reduced, thereby increasing the capability of the upper airway. The pharyngeal fat pad area may play a crucial role in the early stage in overweight patients with OSA. Weight reduction through behavior intervention brings an improvement in obese OSA patients. Treatment for OSA in patients with overweight or obesity includes reduction of fat mass via healthful nutrition, physical activity, antiobesity medications, bariatric surgery, as well as behavior therapy to improve sleep patterns and positional therapy