The Obesity Code

by Jason Fung

Insulin is a key regulator of energy metabolism, and it is one of the fundamental hormones that promote fat accumulation and storage.

Sleeping five to six hours was associated with a more than 50 per cent increased risk of weight gain.26 The more sleep deprivation, the more weight gained.

A single night of sleep deprivation increases cortisol levels by more than 100 per cent.27 By the next evening, cortisol is still 37 per cent to 45 per cent higher.28