New research has examined how sleep loss affects the waistline… and it’s not good news for those who aren’t getting their fair share of nap time
New research presented at the European Congress of Endocrinology in Lisbon, Portugal has focused on the way disrupted sleep patterns can predispose to weight gain, by affecting people’s appetite and responses to food and exercise.
The researchers say that an increasing number of people report routine reduced quality of sleep, often as a result of factors associated with technology and modern living.
Several previous studies have correlated sleep deprivation with weight gain.
The underlying cause of increased obesity risk from sleep disruption is unclear, the researchers say, but may relate to changes in appetite, metabolism, motivation, physical activity or a combination of factors.
Dr Christian Benedict from Uppsala University, Sweden and colleagues conducted a number of human studies to investigate how sleep loss may affect energy metabolism.
These human studies measured and imaged behavioural, physiological and biochemical responses to food following acute sleep deprivation.
The behavioural data revealed that metabolically healthy, sleep-deprived human subjects prefer larger food portions, seek more calories, exhibit signs of increased food-related impulsivity, experience more pleasure from food, and expend less energy.
The group’s physiological studies indicated that sleep loss shifts the hormonal balance from hormones that promote satiety, such as GLP-1, to those that promote hunger, such as ghrelin. Sleep restriction also increased levels of endocannabinoids, which is known to have appetite-promoting effects.
Further work from Dr Benedict’s team shows that acute sleep loss alters the balance of gut bacteria, which has been widely implicated as key for maintaining a healthy metabolism. The same study also found reduced sensitivity to insulin after sleep loss.
“Since perturbed sleep is such a common feature of modern life, these studies show it is no surprise that metabolic disorders, such as obesity are also on the rise,” Dr Christian Benedict says.
Although Dr Benedict’s work has shed light on how short periods of sleep loss can affect energy metabolism, longer-term studies are needed to validate these findings, he says. The group are now investigating longer-term effects and also whether extending sleep in habitual short sleepers can restore these alterations in appetite and energy metabolism.
“My studies suggest that sleep loss favours weight gain in humans,” Dr Benedict says. “It may also be concluded that improving sleep could be a promising lifestyle intervention to reduce the risk of future weight gain.”