Objectives: Aging and reproduction have been independently associated with body shape in women, with redistribution of body fat from lower to upper body regions. This may be interpreted as a life history strategy for allocating energy between competing peripheral fat depots for reproduction, and central fat depots for maintenance and survival. It remains unclear whether men show similar life history strategy in shape. The objectives of this study were to investigate associations between shape, age, and number of offspring in both men and women from Thailand.

Methods: We analyzed data on body shape from three-dimensional photonic scanning, and number of reported offspring, available for 5,889 men and 6,449 women aged 16–90 years from the Thai National Sizing Survey.

Results: Bearing children was associated with increased upper body girths and decreased lower body girths in women, independent of age, weight and height. Unlike motherhood, fatherhood was not associated with shape outcomes indexing adiposity, but was associated with arm girth, which may represent an index of sexual attractiveness. In those without children, aging was associated with greater upper body girths and reduced lower body girths, in both sexes.

Conclusions: Life history strategy in body shape is apparent in both sexes, with aging associated with a shift of tissue away from the lower limb to the upper body. Such strategy may reflect age-changes in the relative costs and benefits of different regional tissue masses. Changes in fat distribution related to aging and reproduction may contribute to the life-course development of cardiovascular risk.