It’s spring break season for kids around the county and if they get into the habit of staying up late, their parents may notice a change in their eating habits during the week. That’s because researchers at the University of Otago in New Zealand have found as little as 40 minutes less of sleep during the night can trigger big changes in eating the next day.

Instead of focusing on dietary changes, the researchers who published their findings in The American Journal of Clinical Nutrition wanted to see if sleep patterns affect a child’s food intake and diet quality.

They worked with a group of 100 students between the ages of 8-12. They worked with parents to move the bedtime of the students up an hour one week and back one hour another week after giving them a week to adjust back to their normal routine in between. The children had their sleep and dietary intake measured, as well as their desire to eat different foods.

It was determined that children who were sleep deprived consumed more calories, mostly after 5 p.m. The majority of their extra consumption came in the form of highly processed foods like cake, cookies and chips. And the parents reported their children appeared to eat in large part as a response to their emotions. And the parents admitted they may have parented differently regarding food when their children had less sleep and exhibited such.

"It may be that during sleep restriction, children showed emotional undereating when offered less desirable, healthier foods—which are often lower in energy—yet exhibited emotional overeating when around highly palatable energy-dense foods, often consumed by people who are considered emotional overeaters," researcher Rosie Jackson said.

Jackson said the extra calorie intake was clinically significant. It was roughly equivalent to three cookies per day and she said if it was not accompanied by extra energy output in the form of exercise or some other activity it could result in excess weight gain over time.

"Although this seems small at the individual level, if a child ate this in excess every day, it would be enough to explain several kilos of extra weight per year—and therefore enough to explain the link between not getting enough sleep and higher body weight," Jackson said. "You only need a small difference in energy intake and expenditure each day to lead to weight gain over time."

Jackson was interested in the subject because of the fact eating behaviors are generally developed early in life and remain pretty constant during childhood.

"However, our study suggests that sleep may be one factor that can influence eating behaviors in children," she says. "It could be as simple as just having more time in the day to eat, but our data also show that food and emotions are tied together when thinking about sleep in children. Getting a good night's sleep is important for so many aspects of our lives, including what and how we eat."

Click here to read more in The American Journal of Clinical Nutrition.