Carbon and nitrogen isotope ratios in hair sampled from 65
communities across the central and intermountain regions of the
United States and more intensively throughout 29 ZIP codes in
the Salt Lake Valley, Utah, revealed a dietary divergence related
to socioeconomic status as measured by cost of living, household
income, and adjusted gross income. Corn-fed, animal-derived
proteins were more common in the diets of lower socioeconomic
status populations than were plant-derived proteins, with individual estimates of animal-derived protein diets as high as 75%;
United States towns and cities averaged 57%. Similar patterns
were seen across the socioeconomic status spectrum in the Salt
Lake Valley. It is likely that corn-fed animal proteins were associated with concentrated animal-feeding operations, a common
practice for industrial animal production in the United States today. Given recent studies highlighting the negative impacts of
animal-derived proteins in our diets, hair carbon isotope ratios
could provide an approach for scaling assessments of animalsourced foods and health risks in communities across the United
States.