Sleeping less may mean you'll eat more: Study
Updated 03:00 PM Mar 16, 2012
LONDON - People who get an hour's less sleep a day develop hunger pangs which make them eat the equivalent of an extra meal, according to new research.
On average volunteers consumed 549 more calories when they were deprived of an hour and 20 minutes' sleep a night - the equivalent of having a hamburger and chips.
Heart disease doctors at the Mayo Clinic, an American healthcare firm, carried out their research after becoming concerned that widespread sleep deprivation could be leading to epidemic levels of obesity.
Population studies have suggested a link but they wanted to find evidence that one actually caused the other by looking at the relationship under laboratory conditions.
To do so, they asked 17 healthy volunteers to live in closed 'Big Brother house' conditions, measuring exactly how much sleep they got, food they ate and physical activity they took.
For the first three nights they were allowed to sleep as much as they liked, averaging 6.5 hours.
Then they were split into two groups, with nine allowed to continue their normal sleeping patterns for eight nights and the remainder reduced to an average of five hours 10 minutes. Food was freely available throughout.
The eating habits of those allowed to sleep freely did not change, while the sleep-deprived ate considerably more.
Professor Virend Somers, a heart disease consultant and the senior study author, said: "The increase was much more than we had expected."
Sleep deprivation is thought to affect food consumption by reducing production of an appetite-suppressing hormone called leptin, and increasing production of an appetite stimulant called ghrelin.
However, The Daily Telegraph reported that this study found leptin levels increased and ghrelin levels fell in the sleep deprived. Prof Somers said that might be because these volunteers got a little fatter over the eight days, "and the more fat you have the more leptin you produce".
He emphasised this was a pilot study, but said it did provide some hard evidence that cutting back on sleep actively increased appetite and made people fatter.
He concluded: "Many young people spend hours at night using technology, on websites like Facebook, which is stopping them from sleeping enough. Is that having an impact on obesity? It may be the case."
The study was presented this week to a meeting of the American Heart Association in San Diego. AGENCIES
On average volunteers consumed 549 more calories when they were deprived of an hour and 20 minutes' sleep a night - the equivalent of having a hamburger and chips.
Heart disease doctors at the Mayo Clinic, an American healthcare firm, carried out their research after becoming concerned that widespread sleep deprivation could be leading to epidemic levels of obesity.
Population studies have suggested a link but they wanted to find evidence that one actually caused the other by looking at the relationship under laboratory conditions.
To do so, they asked 17 healthy volunteers to live in closed 'Big Brother house' conditions, measuring exactly how much sleep they got, food they ate and physical activity they took.
For the first three nights they were allowed to sleep as much as they liked, averaging 6.5 hours.
Then they were split into two groups, with nine allowed to continue their normal sleeping patterns for eight nights and the remainder reduced to an average of five hours 10 minutes. Food was freely available throughout.
The eating habits of those allowed to sleep freely did not change, while the sleep-deprived ate considerably more.
Professor Virend Somers, a heart disease consultant and the senior study author, said: "The increase was much more than we had expected."
Sleep deprivation is thought to affect food consumption by reducing production of an appetite-suppressing hormone called leptin, and increasing production of an appetite stimulant called ghrelin.
However, The Daily Telegraph reported that this study found leptin levels increased and ghrelin levels fell in the sleep deprived. Prof Somers said that might be because these volunteers got a little fatter over the eight days, "and the more fat you have the more leptin you produce".
He emphasised this was a pilot study, but said it did provide some hard evidence that cutting back on sleep actively increased appetite and made people fatter.
He concluded: "Many young people spend hours at night using technology, on websites like Facebook, which is stopping them from sleeping enough. Is that having an impact on obesity? It may be the case."
The study was presented this week to a meeting of the American Heart Association in San Diego. AGENCIES