Abstract
Sleep is a multifaceted biological process linked with biochemical pathways of growth, maturation, and energy homeostasis. Due to the growing complaints of poor sleep in the general population, there has been a significant increase in sleep research aiming to identify the determinants of poor sleep. This review aims to explore the current state of the knowledge on obesity-sleep association and evaluate the role of weight loss in sleep improvement and vice versa. Current evidence suggests three directions of association between obesity and sleep: obesity leading to poor sleep, poor sleep leading to obesity and co-occurrence of obesity and poor sleep. People with obesity often report poor sleep, and obstructive sleep apnoea (OSA), and poor sleepers are often overweight or obese. Weight gain is not only associated with poor sleep and OSA prevalence but also affects the severity of OSA. Poor sleep, specifically OSA, affects metabolic hormones and influence behavioural pathways favouring unhealthy lifestyle leading to further worsening of obesity. Weight loss has shown potential in improving the quality of sleep, reducing OSA severity and decreasing metabolic abnormalities related to obesity. However, weight management is yet to be established as a clinical intervention with a long-lasting effect in improving sleep. Evidence also suggests that improvement in sleep quality lowers the odds of future obesity. Despite, the growing evidence base, the current literature has methodological limitations and fails to establish a causal link between obesity and poor sleep. Nonetheless, it is prudent to advise that weight management should be an important component of the clinical management plans for improving sleep.
