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.