Background and purpose: Prevalence of adolescent obesity has increased worldwide. Although diet and exercise patterns are major determinants of weight, recent studies with adults and children have shown that total amount of sleep is inversely associated with body mass index (BMI). The purpose of this study was to examine associations among total sleep time (TST), hunger, satiety, food cravings, and caloric intake in a sample of healthy adolescents. DESIGN-METHODS: Participants were recruited from the community and a local high school. Demographic data such as sleeping habits, pubertal status, food cravings, caloric intake, physical activity, height, and weight were collected between October 2006 and April 2007. Participants also completed a 7-day sleep-hunger-satiety diary. Descriptive and parametric procedures were used for data analyses (alpha=.05).
Findings: The sample (N=85) included 56% females (n=48), 76% African American (n=65) adolescents. Mean age was 15.6+/-1.4 years and mean BMI was 24.3+/-5.4 kg/m(2). Mean reported 7-day cumulative nocturnal sleep was 52.9 (+/-6.0) hours; mean reported cumulative daytime sleep (or napping) was 3.7 (+/-3.4) hours. Multiple regression analyses showed age, gender, and race were associated with feelings of hunger, satiety, total food cravings and caloric intake. A greater total food-cravings score was associated with increased daytime sleep.
Conclusions: These findings indicate an unexpected association between increased daytime sleep and eating behaviors that potentially lead to obesity. Longitudinal studies using objective measures of sleep, appetite regulation, and caloric intake are needed to better understand relationships between appetite and sleep in adolescents from varying racial and gender groups.
Clinical relevance: By carefully considering adolescent sleep (especially daytime sleep), race, and gender, clinicians and school health nurses in the US and other countries are in a unique position to develop novel approaches to prevent and reduce obesity.