Adipose development is consistent across hunter–gatherers and diverges from western references

Abstract

Despite agreement that humans have evolved to be unusually fat primates, adipose patterning among hunter–gatherers has received little empirical consideration. Here we consider the development of adiposity among four contemporary groups of hunter–gatherers, the Aka, Savanna Pumé, Ju’/Hoansi and Agta using multi-level generalized additive mixed modelling to characterize the growth of tricep skinfolds from early childhood through adolescence. In contrast to references, hunter–gatherers show several consistent patterns: (i) children are lean with little fat accumulation; (ii) no adiposity rebound at 5 years is evident; (iii) girls on average have built 90% of their body size, and reach menarche when adiposity is at its maximum velocity; and (iv) a metabolic trade-off is evident in young, but not older children, such that both boys and girls prioritize skeletal growth during middle childhood, a trade-off that diminishes during adolescence when height velocity increases in pace with fat accumulation. Consistent results across hunter–gatherers living in diverse environments suggest that these patterns reflect a general forager pattern of development. The findings provide a valuable baseline for adipose development not apparent from reference populations. We emphasize both generalized trends among hunter–gatherers, and that inter-populational differences point to the plasticity with which humans organize growth and development.