Objective: To investigate time trends in overweight and Leisure Time Physical Activities (LTPA) in The Netherlands since 1980. Intra-national differences were examined stratified for sex, age and urbanisation degree.
Subjects and methods: We used a random sample of about 140,000 respondents aged 20-69 years from the Health Interview Survey (Nethhis) and subsequent Permanent Survey on Living Conditions (POLS). Self-reported data on weight and height and demographic characteristics were gathered through interviews (every year) and data on LTPA were collected by self-administered questionnaires (1990-1997, 2001-2004). Linear regression analysis was performed for trend analyses.
Results: During 1981-2004, mean body mass index (BMI) increased significantly by 1.0 kg/m(2) (average per year=0.05 kg/m(2)). Trends were similar across sex and different degrees of urbanisation, but varied across age groups. In 20-to 39-year-old women, mean BMI increased by 1.7 kg/m(2), which was more than in older age groups (P<or=0.05). With respect to LTPA, no clear trend was observed during 1990-1997 and 2001-2004. The (absence of) trends were similar across sex and urbanisation degrees, but varied across age groups. During 2001-2004, 20-to 39-year-old women spent approximately 150 min/week less on LTPA compared to older women, while this difference was smaller during 1990-1997.
Conclusions: Mean BMI increased more in younger women, which is consistent with the observation that this group spent less time on LTPA during recent years. Although the overall increase in overweight could not be explained by trends in LTPA, the younger women should be considered as a target group for future physical activity interventions. The influence of the 'obesogenic environment' seems to be similar across different degrees of urbanisation.