A life-course approach in explaining social inequity in obesity among young adult men and women.

OBJECTIVE: To examine the cumulative influence of adverse behavioural, social, and psychosocial circumstances from adolescence to young adulthood in explaining social differences in overweight and obesity at age 30 years and if explanations differ by gender.

DESIGN: A 14-year longitudinal study with 96.4% response rate.

SUBJECT: Data from 547 men and 497 women from a town in north Sweden who were baseline examined at age 16 years and prospectively followed up to age 30 years.

MEASUREMENTS: Overweight and obesity were ascertained at ages 16 and 30 years. Occupation and education were used to measure socioeconomic status. The explanatory measurements were: age at menarche, smoking, physical activity, alcohol consumption, TV viewing, home and school environment, social support, social network, and work environment.

RESULTS: No gender or social difference in overweight was observed at age 16 years. At age 30 years, significantly more men than women (odds ratio (OR) = 2.81, 95% confidence interval (CI) 2.14-3.68) were overweight or obese. Educational level was associated with overweight at age 30 years, but not occupational class. Both men (OR = 1.55, 95% CI 1.10-2.19) and women (OR = 1.78, 95% CI 1.16-2.73) with low education (< or =11 years) were at risk of overweight. The factors that explained the educational gradient in overweight among men were low parental support in education during adolescence, and physical inactivity, alcohol consumption, and nonparticipation in any association during young adulthood. The educational gradient in overweight in women was explained mostly by adolescence factors, which include early age at menarche, physical inactivity, parental divorce, not being popular in school, and low school control. Restricted financial resource during young adulthood was an additional explanatory factor for women. All these factors were significantly more common among men and women with low education than with high education.

CONCLUSION: Social inequities in overweight reflect the cumulative influence of multiple adverse circumstances experienced from adolescence to young adulthood. Underlying pathways to social inequity in overweight differ between men and women. Policy implications to reduce social inequity in overweight include reduction of social differences in health behaviours and social circumstances that take place at different life stages, particularly psychosocial circumstances during adolescence.