Infants and small children who consistently get less than the recommended amount of sleep have a higher risk of being overweight or obese by the age of seven.
"Our study found convincing evidence that getting less than recommended amounts of sleep across early childhood is an independent and strong risk factor for obesity and adiposity," Elsie Taveras, MD, MPH, chief of General Pediatrics at MGHfC and lead author of the Pediatrics paper, said in a Massachusetts General Hospital news release. "Contrary to some published studies, we did not find a particular 'critical period' for the influence of sleep duration on weight gain. Instead, insufficient sleep at any time in early childhood had adverse effects."
Past studies have found links between sleep and obesity in young children, but few have looked at this phenomenon past Body Mass Index (BMI), which is determined on height and weight only.
In this study information was gathered from mothers when their children were six-months, three years, and seven years old. The participants also took surveys when their children were one, two, four, five, and six.
During the exams the researchers recorded the "total body fat, abdominal fat, lean body mass, and waist and hip circumferences" of the children.
"Curtailed sleep" was characterized as" less than 12 hours for children between six months and two years; less than 10 hours for those ages three and four; and less than nine hours for five to seven-year-olds.
Children with the lowers sleep scores tended to have the highest levels of obesity and adiposity; this included harmful abdominal fat.
More research is required to figure out why the link exists, but the researchers suggest a lack of sleep could affect hormones that control appetite as well as interfere with circadian rhythms.
"While we need more trials to determine if improving sleep leads to reduced obesity," Taveras said. "Right now we can recommend that clinicians teach young patients and their parents ways to get a better night's sleep - including setting a consistent bedtime, limiting caffeinated beverages late in the day and cutting out high-tech distractions in the bedroom. All of these help promote good sleep habits, which also may boost alertness for school or work, improve mood and enhance the overall quality of life."
