Characteristics of short sleeping time and eating behaviors related to obesity

To clarify the relation between short sleeping time, obesity and eating behaviors in male workers.

A self-completed questionnaire survey of 680 male daytime workers (age 19-60 years, mean age 42.9 ± 12.5 years) at a manufacturing plant was conducted in 2005. Subjects were divided into two groups by body mass index (BMI): 480 non-obese men with BMI of <25.0 kg/m(2) (mean age 42.8 ± 12.8 years) and 200 obese men with BMI of ≥25.0 kg/m(2) (mean age 43.3 ± 11.7 years). Basic attributes and living habits were then investigated, and the relation of eating behavior to each BMI level was analyzed. BMI and eating behaviors were also investigated in relation to sleeping time.

Sleeping time was significantly shorter in obese men than in non-obese men. Multiple regression analysis showed that sleep time as well as living with family were independent factors for greater BMI. BMI increased as sleeping hours became shorter in the order of ≥9 h, 8 h, 7 h, and ≤6 h. With shorter sleeping time, the mean eating behaviors scores also increased for cognition of constitution, substitution eating and drinking, feeling of satiety, meal contents, eating rhythm abnormalities, and eating style. The mean scores for these eating behaviors all increased with level of obesity, and these behaviors were characteristic of the obese men.

This study showed that people with short sleeping times tended to have eating behaviors of eating more, which can lead to obesity. Short sleeping time may contribute to eating much and then obesity.