Obesity in young Dutch adults: II, daily life-style and body mass index.

The relationships between aspects of daily life-style and age, level of education, and body mass index (BMI; weight/height) were studied in young adult males (n = 1765) and females (n = 2092) in three age groups (19-21, 24-26 and 29-31 yr) in a Dutch population. By means of principal-components analysis five conceptually meaningful factors could be distinguished within the aspects of daily life-style which were considered. These factors were interpreted as constructs of: (1) slimming behaviour; (2) behaviour characterized by the consumption of coffee and alcohol, smoking habits and the number of hours sleep per night (CASS behaviour); (3) eating sweet and savoury snacks between meals; (4) health-conscious behaviour; and (5) physical activity. After adjustments were made for age and level of education, multiple regression analysis showed that slimming behaviour was positively related to BMI in both sexes, CASS behaviour was positively related to BMI in males, and health-conscious behaviour was inversely related to BMI in both sexes. An observed positive relationship between BMI and occupational physical activity in males could be explained by a confounding effect of socio-economic status. The observed weak positive relationship between number of hours active sport per month and BMI in males is possibly due to a difference in lean body mass. The consumption of sweet and savoury snacks was not related to BMI in either sex. These findings suggest that the daily life-style variables should be interpreted as indicators of more general types of behaviour, some of which may be important determinants of obesity.