Lack of sleep has long been linked to obesity, but a new study suggests late night snacking may not be the primary culprit. The latest findings provide the most compelling evidence to date that disrupted sleep alters the metabolism and boosts the body's ability to store fat. The findings add to mounting scientific evidence on how disrupted sleep influences the usual rhythms of the body clock, raising the risk of a wide range of health problems from heart disease to diabetes.
Jonathan Cedernaes, a circadian researcher at Uppsala University in Sweden and the paper's first author, said the findings pointed to "the irreplaceable function that sleep has". "Sleep is not just to conserve energy, it has so many functions," he said.
Time and again research has linked shift work and lack of sleep to the risk of obesity and diabetes, but the reasons behind this association are complex and have been difficult to elucidate. Insufficient sleep appears to disrupt hormones that control appetite and feelings of fullness. Those who sleep less have more time to eat, may be too tired to exercise and have less self-control when it comes to resisting the temptation of unhealthy snacks. A previous study by Cedernaes and colleagues showed that even a short period of sleep deprivation led people to eat more and opt for higher calorie food.
To complicate matters further, obesity increases the risk of sleep apnoea, a breathing problem that itself disturbs sleep quality.
