Late sleepers at risk of becoming overweight
Washington: Staying up late can make you pile on the pounds and is fraught with other negative health consequences.
Late sleepers consumed 248 more calories a day, twice as much fast food and half as many fruits and vegetables as those with earlier sleep times, according to a study by the Northwestern University Feinberg School of Medicine.
They also drank more full-calorie sodas. Late sleepers consumed the extra calories during dinner and later in the evening when everyone else was asleep. They also had a higher body mass index, a measure of body weight, than normal sleepers.
The study is among the first in the US to explore the relationship between the circadian timing of sleeping and waking, dietary behaviour and body mass index, the journal Obesity reports.
"The extra daily calories can mean a significant amount of weight gain - two pounds per month - if they are not balanced by more physical activity," said study co-author Kelly Glazer Baron, health psychologist and neurology instructor at the Feinberg School, according to a Feinberg statement.
"We don`t know if late sleepers consume the extra calories because they prefer more high-calorie foods or because there are less healthful options at night," said Kathryn Reid, research assistant professor in neurology and Glazer`s colleague at Feinberg.
The study shows that the number of calories you eat are important, but so is when you eat them -- and that`s linked to when you sleep and when you wake up, added Phyllis Zee, professor of neurology at Feinberg.
"Human circadian rhythms in sleep and metabolism are synchronised to the daily rotation of the earth, so that when the sun goes down you are supposed to be sleeping, not eating," Zee said.
"When sleep and eating are not aligned with the body`s internal clock, it can lead to changes in appetite and metabolism, which could lead to weight gain," said Zee.