Sleep deprivation made the preschoolers in the research group hungrier, according to the American study.
Increased calorie intake is possibly a reaction to the higher number burned keeping them awake, experts have hypothesised.
Assistant Professor Monique LeBourgeois, lead author of the research at Colorado University Boulder, said, ‘We found that sleep loss increased the dietary intake of preschoolers on both the day of and the day after restricted sleep.’
Researchers studied ten three- and four- year-olds who were all regular afternoon nappers.
Mimicking real-life patterns of lost sleep, they were deprived of roughly three hours on one day.
They had no afternoon nap and were kept up for about two hours past their normal bedtime, before being woken on time the next morning.
During the day of lost sleep, they packed in about 20 per cent more calories than usual, 25 per cent more sugar and 26 percent more carbohydrates.
The following day, the children were allowed to sleep as much as they needed, according to a paper published in the Journal of Sleep Research.
On the recovery day, they still consumed 14 percent more calories and 23 percent more fat than normal.
The results echo other studies linking calorie intake and sleep, but this is believed to be the first looking at young children.
‘To our knowledge, this is the first published study to experimentally measure the effects of sleep loss on food consumption in preschool children,’ said Elsa Mullins, first author of the study.
‘Our results are consistent with those from other studies of adults and adolescents, showing increased caloric intake on days that subjects were sleep deprived.’
The National Sleep Foundation in the US has claimed about 30 percent of preschoolers do not get enough sleep and childhood obesity remains an epidemic, increasing the risk for later life chronic illnesses like diabetes and heart disease.
In 2014/15, 12 per cent of British children were obese by the age of three and 15 per cent were considered to be overweight.
By age five, 9 per cent were obese and 22 per cent overweight. By Year 6, these figures had risen to 19 per cent and 33 per cent respectively.
Parents of the cohort were given no instructions regarding the kind or amount of food or beverages to provide their children.
The children in the study – five girls and five boys – 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.
For homemade dishes, parents recorded ingredients, quantities and cooking methods.
The researchers say the study opens the door for a further studies using larger samples and measuring energy expenditure.
Another previous study found that the developing brain regions of school-age children are the hardest hit by sleep restriction.
Asst Prof LeBourgeois is embarking on further investigations into the impact of insufficient sleep on five-year-olds.