Short sleep duration is associated with obesity and weight gain among children and young adults. However, there are few studies on the elderly, with conflicting results. We examined the association of habitual sleep duration with obesity and weight change among the population aged > or =60 y in Spain. This prospective study was conducted from 2001 to 2003 on 3576 persons whose habitual sleep duration was self-reported in 2001. The outcomes were obesity [body mass index (BMI; in kg/m(2)) > or =30], severe obesity (BMI > or =35), and abdominal obesity (waist circumference >102 cm in men and >88 cm in women) in 2001 and weight gain > or =5 kg in the period 2001-2003. Compared with subjects who slept 7 h, subjects who slept < or =5 h had a greater frequency of obesity [odds ratio (OR): 1.33; 95% CI: 1.00, 1.77] and severe obesity (OR: 2.08; 95% CI: 1.31, 3.32). In addition, sleeping 8 h was associated with obesity (OR: 1.39; 95% CI: 1.11, 1.75) and severe obesity (OR: 1.82; 95% CI: 1.21, 2.73). Similarly, subjects sleeping 9 h were more likely to have severe obesity (OR: 1.57; 95% CI: 1.00, 2.47). Among women, weight gain > or =5 kg was more frequent among subjects sleeping < or =5 h (OR: 3.41; 95% CI: 1.34, 8.69), 8 h (OR: 3.03; 95% CI: 1.29, 7.12), and 9 h (OR: 3.77; 95% CI: 1.55, 9.17). No association was observed between sleep duration and abdominal obesity. Among older adults, sleeping < or =5 h and sleeping 8 or 9 h was associated with obesity and with short-term weight gain in women.
