Tiredness makes us eat more New York - Arabstoday As if being tired from lack of sleep wasn’t punishment enough, now scientists say that not getting a good night’s rest could lead to obesity. Researchers from the Mayo Clinic in Rochester, Minnesota, found that sleep deprived volunteers ate more calories. The researchers studied 17 normal, healthy young men and women for eight nights, with half of the participants sleeping normally and half sleeping only two-thirds their normal time. Participants ate as much as they wanted during the study. ‘We tested whether lack of sleep altered the levels of the hormones leptin and ghrelin [which are associated with appetite], increased the amount of food people ate and affected energy burned through activity,’ said Virend Somers, study author and professor of medicine and cardiovascular disease at the Mayo Clinic. The sleep deprived group, who slept one hour and 20 minutes less than the control group each day consumed an average 549 additional calories each day. Meanwhile, the amount of energy used for activity didn't significantly change between groups, suggesting that those who slept less didn't burn additional calories. ‘Sleep deprivation is a growing problem, with 28 per cent of adults now reporting that they get six or fewer hours of sleep per night,’ said Andrew D. Calvin, co-investigator, cardiology fellow and assistant professor of medicine at the Mayo Clinic. The researchers stressed, though, that that while the study suggests sleep deprivation may be an important part and one preventable cause of weight gain and obesity, it was a small study conducted in a hospital's clinical research unit. ‘Larger studies of people in their home environments would help confirm our findings,’ Calvin said.