Several measures of poor sleep quality were associated with higher body mass index (BMI) in children, according to data presented at the American Association for Cancer Research Special Conference Obesity and Cancer: Mechanisms Underlying Etiology and Outcomes.
Around one in five children aged six to 19 is obese, according to recent statistics from the US Centers for Disease Control and Prevention which is more than triple the rate seen in the 1970s. Obesity is linked with substantial effects with are both immediate and long-term. Childhood obesity is often linked with adult obesity and this is lined with a risk of developing obesity-related cancers later in adult life.
Sleep patterns affect obesity in adults but the majority of reserach in children has focused on length of sleep rather than sleep quality.
The researchers studied 120 children aged around eight years whose mothers had participated in the Newborn Epigenetic Study which examines how environmental factors and nutrition pre-birth and during early childhood, affect gene function. The population was controlled for maternal age, sex, race and education as an indicator of socioeconomic status.
Children wore accelerometers 24 hours per day for at least five days to track the sleep-wake cycle. Children completed the eating in the absence of hunger test i.e. they ate a meal and reported when they were full after. The amount of food they ate once they had reached satiety was tracked.
Results shows that shorter sleep duration was associated with a higher BMI z-score (body mass index adjusted for age and sex). Each additional hour of sleep was associated with a .13 decrease in BMI z-score, and with a 1.29 centimetre decrease in waist circumference.
The researchers conclude that although sleep duration is important, examining markers of sleep quality may also be useful in designing childhood obesity prevention strategies. An excess of screen time and distractions from sleep in the bedroom may be contributing to fragmented sleep claim the researchers. And, in order to reduce the incidence of cancer in adulthood, tackling obesity via greater sleep quality and quantity in childhood may be an important preventive measure.
- American Association for Cancer Research (AACR). Quality of children's sleep may affect eating habits and weight: Poor sleep is associated with obesity, which can increase cancer risk. AACT 2018 [online]. [Source]