Associations between parental and offspring adiposity up to midlife: the contribution of adult lifestyle factors in the 1958 British Birth Cohort Study.

BACKGROUND Parent-offspring associations in adiposity are well known, but the extent to which they are explained by modifiable environmental and lifestyle factors remains to be elucidated. OBJECTIVES The objectives were to assess whether 1) parent-offspring associations in body mass index (BMI; in kg/m(2)) persist from childhood to midadulthood, 2) parental BMI is associated with the offspring's adult lifestyle, and 3) parent-offspring BMI associations in midadulthood are explained by lifestyle factors. DESIGN Participants in the 1958 British Birth Cohort Study and their parents (n = 9346) were examined. Parental BMI was assessed in 1969; offspring (ie, cohort members) BMI was ascertained prospectively at 11 and 44-45 y. Lifestyle factors of the offspring, including diet, physical activity, alcohol consumption, and smoking, were assessed prospectively in adulthood. RESULTS Maternal and paternal BMI were positively associated with offspring BMI in both childhood and midadulthood, and the strength of the association did not diminish with offspring age. Maternal BMI was associated with several offspring lifestyle factors across adulthood; fewer associations were observed for paternal BMI. Parent-offspring BMI associations in adulthood were largely maintained after adjustment for multiple lifestyle and socioeconomic factors at different life stages: if parental BMI was 1 unit higher, offspring BMI at 44-45 y was higher by between 0.21 and 0.29 units in adjusted models. CONCLUSIONS Strong parent-offspring BMI associations are maintained into midlife. These associations are largely unaffected by adjustment for a wide range of lifestyle factors. Offspring of obese parents are an important target for interventions aimed at reducing population levels of overweight and obesity.