Association of sleep duration with weight and weight gain: a prospective follow-up study
The objective of this study was to examine the associations of sleep duration with subsequent weight and major weight gain in women and men during a follow-up period of 5–7 years. The data were derived from the Helsinki Health Study cohort mail questionnaire surveys among 40–60-year-old employees of the City of Helsinki, Finland. At baseline in 2000–2002, 8960 people responded to the survey (80% women, response rate 67%). The follow-up survey was conducted in 2007 among all respondents to the baseline survey (n = 7332, response rate 83%). Sleep duration (5 h or less up to 10 h or more) and weight and weight gain of at least 5 kg were based on self-reports. Analyses of variance and logistic regression analyses were used to examine the associations between sleep duration and weight, as well as major weight gain. Short sleep duration was associated with major weight gain [odds ratio (OR) 1.52; 95% confidence interval (CI) 1.08, 2.14] during the follow-up. Adjusting for several covariates had only minor effects on that association. Long sleep duration was associated with major weight gain after adjusting for age (OR 1.35; 95% CI 1.00–1.81). No associations were found among men. Sleep duration was associated with major weight gain among middle-aged employed women. Short sleep may be a risk factor for subsequent weight gain.