It’s not news that sleep is critical for good health and proper child development. But what is becoming clearer is the fallout of not getting the right kind of rest. A new study has linked poor sleep quality to higher body mass index (BMI) in children, even when kids are getting ‘enough’ rest.

A rising obesity rate is a looming health problem for India in general; among its children, the figures vary, but roughly 1 in every 13 Indian children is overweight or obese.

“Childhood obesity very often leads to adult obesity,” said the study’s lead author, Bernard Fuemmeler, PhD, MPH, professor and associate director for cancer prevention and control at Virginia Commonwealth University’s Massey Cancer Center. “This puts them at greater risk of developing obesity-related cancers in adulthood.”

Earlier research, Fuemmeler explained, has shown sleep patterns play a role in obesity in adults, but most research exploring the connection between sleep and obesity in children has focused on the duration of sleep, rather than the way quality of sleep or circadian patterns affect eating behaviors and weight.

In this study, Fuemmeler’s team enrolled 120 kids whose average age was 8. Researchers controlled for age, sex, race, and maternal education as an indicator of socioeconomic status. To track the sleep-wake cycle, the kids wore accelerometers continuously for 24 hours per day, for a period of at least five days. To gauge eating habits, kids completed the “eating in the absence of hunger test”: Kids ate a meal and reported when they were full; then researchers tracked how much food the kids ate afterward.

Some interesting findings emerged. Less sleep was associated with a higher BMI (adjusted for age and sex). Conversely, every additional hour of sleep was associated with a decrease in BMI and a 1.29-centimeter decrease in waist circumference.

More fragmented sleep, measured by the frequency and duration of transitions between sleep and wakefulness, was also associated with greater waist circumferences. And the earlier the child woke naturally, the higher intake of calories he or she tended to consume after reaching satiety.

“Today, many children are not getting enough sleep,” Fuemmeler said. “There are a number of distractions, such as screens in the bedroom, that contribute to interrupted, fragmented sleep. This, perpetuated over time, can be a risk factor for obesity. Because of the strong links between obesity and many types of cancer, childhood obesity prevention is cancer prevention, in my view.”

While the study did not encompass data that could have helped researchers assess whether sleep quality influences weight gain, or weight influences sleep quality, Fuemmeler seems to be banking on the former, suggesting families would benefit from following pediatric sleep guidelines.