Sex differences in the association between sleep and body mass index in adolescents

J Pediatr. 2005 Dec;147(6):830-4. doi: 10.1016/j.jpeds.2005.07.019.


Objective: To determine whether an association between short sleep duration and increased body mass index (BMI) exists in a sample of U.S. adolescents.

Study design: Public-use dataset of the National Longitudinal Study of Adolescent Health. Final sample included 4486 adolescents (51% female). Main outcome was BMI transformed into z-scores for age and sex using reference values from the Centers for Disease Control/National Center for Health Statistics. Overweight was defined as > or =95th percentile. Linear and logistic regression models were calculated. Sleep duration was self-reported in hours. A quadratic term for sleep was added to test curvilinear association. Covariates included age, race, parental education, activity and inactivity scores.

Results: Among males, linear regression indicated that sleep duration significantly predicted BMI z-score (Beta = -0.08, 95% CI: -0.12, -0.03). Logistic regression indicated that sleep duration predicted risk of overweight among males (OR = 0.90, 95% CI: 0.82, 1.00). Sleep duration was not a significant predictor among females in either regression model. Quadratic term for sleep was not significant for either sex.

Conclusions: Longer sleep duration was weakly associated with lower BMI and risk of overweight among male adolescents only. This sex-related difference may be due to differences in the physiology of puberty or in sleep characteristics.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Body Mass Index*
  • Female
  • Humans
  • Linear Models
  • Logistic Models
  • Longitudinal Studies
  • Male
  • Obesity / epidemiology
  • Overweight*
  • Risk Factors
  • Sex Factors
  • Sleep Deprivation / epidemiology
  • Sleep*
  • United States / epidemiology