The association between father's social class and adult obesity is not explained by educational attainment and an unhealthy lifestyle in adulthood

Objectives: To investigate the effect of father's social class on central and general obesity in adulthood. To test the role of educational attainment and adult health behaviours as mediators in this association. Methods: BMI, Waist-hip-ratio, smoking status, alcohol consumption, leisure-time physical activity and dietary intake (semi-quantitative food-frequency questionnaire) were assessed at phase 5 (1997-1998) of the Whitehall II cohort study. We used retrospective data on educational attainment and father's social class. Our study sample was 4598 participants (3364 men, 1234 women) aged 44-69, with a valid obesity measure and information on father's social class and educational attainment. Results: Father's social class was inversely associated with adult life central (Waist-hip-ratio) and general (BMI) obesity in women but not in men. For example, mean BMI difference between the highest and lowest childhood social class was 2.04 kg/m(2) (95% confidence intervals: 0.90; 3.18). These associations remained robust to adjustment for adult life socioeconomic position. Adjusting for educational attainment resulted in a reduction of 10-15% in the difference in mean obesity measures between lowest and highest father's social class. In our fully adjusted model, adult life health behaviours did not provide further attenuation of the effect of father's social class on adult obesity. Conclusion: We provide evidence for an independent effect of father's social class on adult central and general obesity in women, which is not explained by educational attainment and an unhealthy lifestyle in adulthood. Policies aiming at reducing inequalities in obesity should tackle the problem of social inequality early in life.