Victoria Adele Tobolsky

Grant Type

Dissertation Fieldwork Grant

Institutional Affiliation

Harvard U.

Grant number

Gr. 9851

Approve Date

April 30, 2019

Project Title

Tobolsky, Victoria (Harvard U.) "Investigating Energetic Contributions to Adolescent Growth Among Kalenjin Children"

Children undergo a characteristic period of insulin resistance during puberty, a life history stage that marks the transition from investment in growth to investment in reproduction. Insulin resistance differs across tissues, however, potentially shunting glucose, the body’s main energy source, to areas undergoing high amounts of growth. This study explores the role of energy balance, insulin production, and insulin sensitivity during adolescent development among Kalenjin girls of Western Kenya, testing the hypothesis that energy balance and insulin resistance during puberty mediate energy allocation to somatic growth. Serial urine samples, blood spots, anthropometric measurements, and diet and physical activity self-report questionnaires will be used to test the relationship between insulin levels, bone turnover biomarkers, and height when controlling for known covariates like IGF-1, gonadal steroids, and GH. This study will also test the relationship between the timing and magnitude of this period of insulin resistance relative to energy balance, hypothesizing that Kalenjin children with higher energy balance undergo an earlier and relatively greater period of insulin resistance than children with lower energy balance. These relationships are essential to disentangle as more of the world undergoes a nutrition transition away from the energy constrained environments typical of our evolutionary history.