Adolescent sleep characteristics and body-mass index in the Family Life, Activity, Sun, Health, and Eating (FLASHE) Study

Abstract

Sleep may play a role in overweight and obesity in adolescents. the objective of this study is to investigate the relationships between sleep duration and timing and overweight and obesity status in adolescents, with a special emphasis on weekday-weekend difference in sleep characteristics as well as sex-specific relationships. We examined 1,254 U.S. adolescents (12-17 years) self-reported sleep duration, timing, weekday-weekend differences in duration and timing in relation to overweight and obesity. We found an inverse association between sleep duration and overweight and obesity. Compared to 8-9 h of sleep, short sleep (< 7 h) on weekdays was associated with higher odds of overweight and obesity [Odds ratio (95% confidence interval), 1.73 (1.00, 2.97)] in the overall population, while long sleep (10+ h) on weekends was associated with lower odds, but only in males [0.56 (0.34, 0.92)]. We also found that a larger weekday-weekend difference in sleep duration was associated with overweight and obesity in females, but not in males. Specifically, the odds of overweight and obesity were significantly higher among females reporting longer sleep on weekends than weekdays by ≥ 2 h [2.31 (1.15, 4.63)] when compared to those reporting little weekday-weekend differences. Sleep timing, or weekday-weekend differences in sleep timing, were not associated with overweight and obesity in the overall population, although we found suggestive evidence linking later weekend sleep with overweight and obesity in females. Our findings support a role of sleep in adolescent obesity and suggest sex-differences in this relationship that warrant future studies. Adolescents who are overweight and obese are at a greater risk of developing a wide range of health conditions in adulthood, including high blood pressure, heart disease and strokes, certain types of cancer, kidney disease, and type II diabetes 1. Emerging evidence suggests that sleep deficiency may be an important risk factor for overweight and obesity in childhood and adolescence. However, findings from previous studies are mixed, with some reporting negative associations between sleep duration and body-mass index (BMI) 2-5 , others reporting U-shaped associations similar to findings in adults 6 , and some reporting no associations at all 7. Recent studies suggested that later sleep timing and propensity of eveningness may also be associated with higher BMI 8-12. This may be due to more severe misalignment between the internal circadian cycles and the behavioral sleep-wake cycles that are partially influenced by social and environmental factors such as school schedules and social obligations 13,14. It has been well documented that chronotype shifts later during adolescent years 14. Many middle and high schools have a relatively early start time, and this mismatch between school schedules and chronotype-determined sleep window may lead to sleep deficiency on weekdays among adolescents. Moreover, sex-differences in chronotype and sleep patterns have been reported among adolescents, ...

Sleep Quality and Duration in European Adolescents (The AdolesHealth Study): A Cross-Sectional, Quantitative Study

“…This data is similar to that previously found for sex and the region or country of origin [91]. Physiological [57], psychological [92] and social [93] differences between sex, as well as cultural differences [66,94] between different regions or countries could explain this. It is important to conduct further research to clarify the causes and (importantly) consequences, of these two factors, that is, the relationship between them and the quality/quantity of sleep (i.e., sedentary lifestyle, physical inactivity, screen exposure, poor diet or inadequate eating behaviors, stress, etc.).…”

“…This is despite the fact that we found a non-statistically significant decrease in the duration of sleep, as the age of the subjects of the populations of Seville and Reykjavik increases. Prior findings show that as adolescents get older, their use of electronic devices and their time spent on screens increases, consequently reducing the duration of their sleep [65][66][67].…”

Associations Between Sleep Duration, Wake-Up Time, Bedtime, and Abdominal Obesity: Results From 9559 Chinese Children Aged 7–18 Years

“…In recent years, sleep timing, including wake-up time and bedtime, is another important modifiable behavior, which is closely related to childhood obesity. Although there were many studies regarding the associations between wake-up time, bedtime, and childhood obesity, the results were inconsistent ( 11 , 23 , 24 ). Additionally, few studies on the associations of wake-up time, bedtime with abdominal obesity among Chinese children were available.…”

“…Therefore, this study aimed to investigate the associations between sleep duration, wake-up time, bedtime, separately on weekdays and weekends, and childhood abdominal obesity. Moreover, since age-specific and sex-specific associations have been reported in the literature between sleep duration and childhood obesity ( 13 , 23 ), these associations regarding sex and age differences were also explored.…”

Impact of Childhood Obesity and Psychological Factors on Sleep

“…In children and adolescents, higher BMI zscore and waist circumference have been associated with poorer sleep quality and behaviors (4,15,16), and higher body fat percentage has been associated with later average bed times (16). The relationship between average sleep duration over the week and childhood obesity has slightly mixed findings (6,14,17,18); however, shorter sleep duration on school days specifically has been associated with higher BMI z-scores (19) and increased prevalence of eating in the absence of hunger (14). It is further evident in comparisons between children and adolescents receiving weight-loss treatment and their normal-weight peers, with studies finding that 88% of children participating in a weight-loss program sleep less than recommended (20) and that inpatient weight-loss program participants have shorter and more disturbed sleep than controls (4).…”