WASHINGTON: Young children who miss daytime nap and also stay up late at night are likely to consume more calories than usual, increasing their risk of obesity, a new study has warned.
In the study, preschoolers, all regular afternoon nappers, were deprived of roughly three hours of sleep on one day – they had no afternoon nap and were kept up for about two hours past their normal bedtime – before being awakened at their regularly scheduled times the next morning.
During the day of lost sleep, the 3- and 4-year-olds consumed about 20 per cent more calories than usual, 25 percent more sugar and 26 per cent more carbohydrates, said study lead author Monique LeBourgeois from University of Colorado at Boulder in the US.
The following day, the kids were allowed to sleep as much as they needed. On this “recovery day,” they returned to normal baseline levels of sugar and carbohydrate consumption, but still consumed 14 per cent more calories and 23 per cent more fat than normal.
“With this study design, children missed a daytime nap and stayed up late, which mimics one way that children lose sleep in the real world,” said Ms LeBourgeois.
“We found that sleep loss increased the dietary intake of preschoolers on both the day of and the day after restricted sleep,” she said.
These results may shed light on how sleep loss can increase weight gain and why a number of large studies show that preschoolers who do not get enough sleep are more likely to be obese as a child and later in life.
Overweight youth are about four times more likely to be obese as adults. “The parents were given no instructions regarding the kind or amount of food or beverages to provide their children,” said Ms LeBourgeois. They fed their children just like they would on any normal day.
Researchers also studied each child across all study conditions – meaning when their sleep was optimised, restricted and recovered – which gave them control over how kids could differ individually in their eating preferences and sleep.
The children in the study – five girls and five boys – each wore small activity sensors on their wrists to measure time in bed, sleep duration and sleep quality.
Parents logged all food and beverages consumed by the preschoolers, including portion sizes, brand names and quantities, using household measures like grams, teaspoons and cups.