We examined the prevalence of metabolic syndrome and its related factors to support the health of Mine City residents. We enrolled 1,871 subjects, consisting of 1,186 men and 685 women, aged 20 to 92 years. Inclusion criteria were those who underwent health checkups at Mine City Hospital and answered a lifestyle questionnaire. The overall prevalence of metabolic syndrome among the subjects was 14.7%. Significantly more men than women were classified as having metabolic syndrome or being at risk for metabolic syndrome across all age groups （youth, middle age, and elderly）. Moreover, particularly high rates were observed among middle-aged and elderly men. Blood pressure was significantly higher in men than women during youth and middle age, showing an upward trend with increasing age. Fasting blood glucose was significantly higher in men than women across all age groups and showed an upward trend with increasing age. LDL cholesterol was significantly higher in men than women in the youth age group. LDL cholesterol increased with age in women, whereas no significant differences were observed among age groups in men. HDL cholesterol was significantly lower in men than women across all age groups, showing an increasing trend with advancing age. The proportion of individuals not meeting national physical activity guidelines was high among men in middle age and among women in youth and middle age. No sex difference was observed in sedentary time; however, it was shorter in the elderly compared with the youth and middle-aged age groups in both men and women. Scores for dietary behaviors associated with obesity risk decreased with increasing age in both men and women, with a sex difference observed only in the elderly age group. These findings provide useful guidance for health support aimed at preventing and managing metabolic syndrome in the general population.