The long-term effects of sociodemographic and health characteristics on television viewing (TV) time changes have not been identified in adulthood. We aimed to examine the modifiable and non-modifiable determinants of changes in TV-time in young adults over 10 years.

Participants (N = 2929) aged 24-39 years were recruited between 2001 and 2011 from the Cardiovascular Risk in Young Finns Study. Data were collected using questionnaires and a medical examination. The determinants of changes in TV-time were estimated using latent growth modeling for men and women separately.

For men, inverse associations with initial levels of TV-time were observed for students becoming employed and already has children, and direct associations were observed for both those who stayed a smoker and those who stayed overweight/obese. Increasing attention to health habits was inversely associated with a slope of TV-time, whereas age and becoming unemployed were positively associated with the slope of TV-time. For women, inverse associations with the levels of TV-time were found for age, staying in non-manual work, and paying consistently high and increasing attention to health habits, and direct associations were found for staying unemployed, smoking and overweight/obese, and becoming employed, single and non-smoking. Increasing physical activity, becoming employed, motherhood, and normal weight were inversely associated with the slope of TV-time, whereas age and staying in non-manual work were positively associated with the slope of TV-time.

This suggests several gender-specific determinants of changes in TV-time that can help identify potential targets for interventions to prevent excessive TV-time in adulthood.