Additive influences of maternal and paternal body mass index on weight status trajectories from childhood to mid-adulthood in the 1970 British Cohort Study

Abstract

This study aimed to (i) describe the weight status trajectories from childhood to mid-adulthood and (ii) investigate the influence of maternal and paternal body mass index (BMI) on offspring’s trajectories in a nationally representative study in Great Britain.  The sample comprised 4174 (43%male) participants from the 1970 British Cohort Study with complete BMI data at ages 10, 26, 30, 34, and 42 years. Individuals’ weight status was categorised as overweight/obese or non-overweight/obese at each age, and trajectories of weight status from 10 to 42 years of age were assessed. Sex-stratified multinomial logistic regression models were used to assess associations of maternal and paternal BMI with trajectory group membership, adjusting for potential confounders (e.g., socioeconomic position and puberty). 30% of individuals were never overweight/obese (reference trajectory), 6%, 44% and 8% had childhood, early- and mid-adulthood onset of overweight/obesity (respectively), and 12% other trajectories. In fully adjusted models, higher maternal and paternal BMI significantly increased the risk of childhood (relative risk ratio: 1.2-1.3) and early adulthood onset (1.2) of overweight/obesity in both sexes. Relative risk ratios were generally higher for maternal than paternal BMI in females but similar in males. Early puberty also increased the risk of childhood (1.8-9.2) and early adulthood onset (3.7-4.7) of overweight/obesity. Results highlight the importance of primary prevention, as most individuals remained overweight/obese after onset. Maternal and paternal BMI had additive effects on offspring weight status trajectories across 32 years of the life course, suggesting that prevention/intervention programmes should focus on the whole family.