A new study out of the University of Colorado Boulder and the University of Michigan reported that preschoolers who missed their naps and stayed up later at night were more likely to gain weight due to increased sugar and carbohydrate intake. A paper on the study was published in the Journal of Sleep Research.
In this study, researchers deprived preschoolers their regular afternoon nap and kept them awake two hours after their normal bedtime, accounting for a total of three hours’ sleep loss. The children were awakened at their regular time the next morning.
Monique LeBourgeois, lead author of the study, noted that on the day of the sleep loss, the children took in about 20% more calories than they normally would, including 26% more carbohydrates and 25% more sugars. On the next day, “recovery day,” the children could sleep as much as they wanted. They all returned to their normal sugar and carbohydrate consumption levels; however, they still had 23% more fat and 14% more calories than usual.
This study included a loss of nap and staying up late, which accurately mimics the type of sleep loss that would happen in the real world. The National Sleep Foundation notes that approximately 30% of preschool aged children are sleep deprived.
It was notable that dietary intake was increased both the day of sleep loss and the day after. This may give insight into how sleep deprivation can lead to weight gain and childhood obesity.
Even with prevention measures for obesity over the last decade, the problem of childhood obesity continues to rise to epidemic levels. About 23% of children in the U.S. under the age of 5 are overweight or obese, according to a 2014 study. Obese and overweight children are at higher risk of chronic illnesses later in life such as depression, low self-esteem, diabetes, and heart disease. Overweight children are four times more likely to suffer from obesity as an adult.
Dr. LeBourgeois notes that this study was beneficial because there was no control of the dietary intake. Parents did not restrict or enforce any of their child’s food and drink intake. The parents fed the children the same foods they would eat on any given day.
Additionally, researchers reviewed each child individually based on study conditions like when sleep was restricted, when it was recovered, and when it was optimized. This gave scientists control over how the children differed in their eating habits, preferences, and sleep routines.
Five girls and five boys participated in the study. Each of the children were given small sensors on their wrists to monitor activity, time in bed, sleep quality, and sleep duration. Parents were asked to keep track of all food and drinks their child took, including brands, quantities, and portions using measures in grams, teaspoons, and cups. All ingredients, including spices, were logged for all homemade dishes, including cooking methods and quantities.
This study is the first of its kind to measure the effect sleep has on food consumption in preschool aged kids. Results of this study are consistent with other studies that have been done on teens and adults.
Follow-up studies using larger samples to confirm these findings are in line to start. These studies will be experimental and control food and beverage intake, as well as objectively measure energy levels in children.
Rachael Herman is a professional writer with an extensive background in medical writing, research, and language development. Her hobbies include hiking in the Rockies, cooking, and reading.