The work presented in this dissertation highlights the use of stable isotope ratio biomarkers in fingernail tissues to reconstruct diet and travel histories that may have direct applications to nutrition and forensic science studies.
The specific goal of this study was to examine the use of stable isotope ratio measurements using fingernail keratin to assess two aims: first, to examine individual diets and changes in diets over time, and then to assess their utility for region of origin and travel history reconstruction in resident and nonresident populations. Those aims are examined and discussed in four chapters of this dissertation, with a focus on two research studies (high school and a resident and nonresident population studies) conducted in Salt Lake City, Utah. Results of the study revealed that fingernail keratin tissues are useful to reconstruct diet and travel history among individuals; fingernail isotope ratios of adolescents uncovered socioeconomic patterns and highlighted the importance of school lunch programs on adolescent diets. Also, fingernail isotope ratios displayed patterns that were consistent with reported travel history and when compared to prediction models for isotope turnover performed well.