Parental exposure to famine in early life and child overweight in offspring in Chinese populations

Little is known about the transgenerational effect of nutrition deficiency in early life. This study aimed to evaluate the associations of fetal and childhood exposure to famine of parents with their offspring's risk of overweight during childhood.This analysis included a total of 3734 participants of the China Health and Nutrition Survey aged 1-17 years whose fathers and/or mothers were born in 1955-1966. These children were classified into subgroups according to parental famine exposure status (unexposed and exposed) and timing (fetal-exposed and childhood-exposed). Random effects models were applied to evaluate the associations of parental famine exposure with body mass index (BMI) and overweight of offspring. Fractional polynomial functions were adopted to describe trajectories of BMI against age.Compared with children of unexposed parents, there was a lower risk of overweight among offspring of childhood-exposed fathers [OR (95%CI): 0.80 (0.61, 1.04)] or exposed parents [0.84 (0.68, 1.04)], particularly among male offspring, but not among those with exposed mothers only [0.98 (0.65, 1.47)]. For BMI, children with exposed mothers only had a slightly higher BMI [β(95%CI): 0.17 (-0.15, 0.49)], while those with exposed fathers only had no difference [-0.02 (-0.23, 0.19)] or exposed parents had a slightly lower BMI [-0.17 (-0.33, 0.00)] (p < 0.05 for interaction between maternal and paternal exposures). Stratified analysis showed little heterogeneity between male and female offspring, but the association between paternal childhood exposure to famine and lower overweight risk in offspring was more evident in high (vs low) paternal education group (p for interaction< 0.05).The transgenerational associations of early-life exposure to famine with lower risks of child overweight may be via the paternal line and differ by the educational levels of parents. Further studies are warranted to confirm the results and reveal the biological mechanisms underlying.