Aging is influenced by genetic, environmental, and lifestyle factors, with biological age often assessed via DNA methylation-based epigenetic clocks. This study explores the relationship between lifestyle and biological age using cross-sectional data from the Lifelines cohort. Lifestyle, including self-reported physical activity and diet habits, and biological age based on DNA methylation data will be analyzed through multivariate regression and stratified analyses to examine associations and variations by age, sex, and health status. Understanding how lifestyle impacts biological aging could inform public health strategies, personalized interventions, and disease prevention. It is hypothesized that healthier lifestyle habits correlate with younger biological ages.