A lot of people are suffering from low energy level and sleepiness during daytime requiring afternoon nap.The reason for that might be sleep apnea syndrome which is highly likely if the person is obese and snores.During nighttime such people might have intermittent airway closure resulting in frequent awakening and inefficient sleep.
Therefore when such person wakes up, he doesn’t have enough energy because of sleep deprivation. Instead he needs more sleep — afternoon nap. The solution of this problem is weight loss.