A new study, led by the University of Washington, has found that sleeping for more than nine hours daily may help a person shed weight -- this is because it counteracts a genetic predisposition to obesity.
In the study of twins, the researchers have found that sleeping for less than seven hours a night was linked to higher bodyweights and a greater susceptibility to genetic factors that influence weight.
However the opposite was true in people who slept for nine hours or more, 'The Daily Telegraph' reported.
Several genes have been found to be associated with obesity and this is thought to be the first study to examine how sleep interacts with them. The genes affect how the body uses energy, how fat is stored, the feeling of being full after a meal and how quickly sugar is used up.
In fact, the researchers analysed 1,088 pairs of twins and found that the genetic influence on their body mass index was twice as great in those who slept for less than seven hours compared to those who slept for nine hours a night.
Lead author Nathaniel Watson said: "The results suggest that shorter sleep provides a more permissive environment for the expression of obesity related genes. Or it may be that extended sleep is protective by suppressing expression of obesity genes."
Dr Watson said the results were preliminary but may suggest that weight loss measures would be most effective when the genetic influences on obesity were mitigated through sleep extension.
The findings were published in the Sleep journal. PTI MOT MOT
