Objective: The aim was to study the associations of physical activity and socioeconomic status with overweight from 1978 to 2002 and to explore whether the trend in overweight was different across educational groups or leisure time and commuting physical activity groups.
Method: The study population comprised 37,084 women and 34,191 men who participated in cross-sectional postal surveys carried out annually from 1978 to 2002. The surveys included independent nationally representative random samples of Finns aged 25 to 64 years. Information on weight, height, leisure time and commuting physical activity was self-reported. The level of education was obtained from national register data. Overweight was defined as a body mass index (kg/m2) of 25 or higher.
Results: Overweight was more prevalent among the physically inactive and lower educated. The prevalence of overweight increased over time. Across the study years, those men and women who participated in leisure time or commuting physical activity had a lower prevalence of overweight in all educational groups. The increase in the prevalence of overweight followed a similar pattern in all physical activity and education groups.
Conclusion: Engagement in physical activity has not prevented an increase in the prevalence of overweight in any socioeconomic group among Finnish men and women from 1978 to 2002.