London: A sign of alarm for sleep-deprived individuals. Scientists have indicated that just one night of sleep deficiency can lead to weight gain.
It slows down the body's metabolism the next morning, meaning less energy, in the form of calories, is burnt off.
Previous studies have linked sleep deficiency with an increase in hunger-related hormones during waking hours.  
"Our findings show that one night of sleep deprivation acutely reduces energy expenditure in healthy men, which suggests sleep contributes to the acute regulation of daytime energy expenditure in humans," the Daily quoted Christian Benedict, who led the research at Uppsala University in Sweden, as saying.
He and his colleagues put 14 male students through a series of sleep 'conditions' - shortened sleep, no sleep, and normal sleep - over several days, then measured changes in how much they ate, their blood sugar, hormone levels and metabolic rate.
Even a single night of missed sleep slowed metabolism the next morning, reducing energy expenditure for tasks such as breathing and digestion by between 5 and 20 per cent.
Sanford Auerbach, head of the Sleep Disorders Center at Boston Medical Centre, pointed out that sleep deficiency is a complex issue, with medication and other issues influencing sleep as well, and urged that the new findings be kept in context. 
"They showed that we adapt to sleep deficiency and that some of these adaptations could theoretically contribute to obesity," he added, adding that it's not clear how chronic sleep loss influences hormone levels.