MRCP2-4246

A 60-year-old man visits his doctor after his spouse complains about his loud snoring and occasional cessation of breathing during sleep. He also experiences daytime sleepiness while watching TV or reading. The patient had tonsillectomies and adenoidectomy in childhood. During examination, his height is 1.80m and weight is 100kg. Despite losing 15kg in the past six months, his symptoms persist. The doctor refers him for a sleep study which indicates moderate sleep apnoea. What is the initial management option that should be recommended?