Sex-Specific Associations of Famine Exposure in Early Life with Body Shape Indices Across Two Generations in China

Background/Objectives: Early-life undernutrition may exert lifelong and intergenerational effects on height and weight, but its impact on body shape remains unclear. Using the Great Chinese Famine (1959–1961) as a natural experiment, this study explored the associations between early-life undernutrition and body shape indices across two generations. Methods: We analyzed nine waves of longitudinal data from the China Health and Nutrition Survey (1991–2015), including 5156 participants (F1) born in 1955–1966 and their 2383 biological offspring (F2). F1 famine exposure was classified by birth year; F2 exposure was defined by parental status. Anthropometric indices including body adiposity index (BAI), body roundness index (BRI), waist-to-height ratio (WHtR), conicity index (COI), and a body shape index (ABSI) were derived from repeated measurements. Age-specific fitted curves of these indices were compared across exposure groups using mixed-effects models with fractional polynomials of age. Results: Fetal famine exposure was modestly associated with lower COI and ABSI in adulthood, particularly among men. Childhood famine exposure was significantly linked to lower BAI (−0.40), BRI (−0.26), WHtR (−0.0140), COI (−0.0188), and ABSI (−0.0008), with stronger associations in men (all P for sex interaction <0.05). Intergenerationally, maternal childhood exposure was associated with higher offspring BAI, whereas paternal childhood exposure was associated with lower BAI, BRI, WHtR, COI, and ABSI. Conclusions: Famine exposure showed more pronounced associations with body shape in men, and maternal and paternal exposures displayed different intergenerational patterns. These exploratory findings suggest the possibility that early-life undernutrition may relate to long-term phenotypes in a sex-specific manner, though this requires independent replication.