Abstract. Obesity is a predictor of multiple negative health outcomes, including type 2 diabetes, coronary
heart disease, hypertension, various cancers, and premature death. Today, nearly two-thirds of US adults are
overweight or obese, and one out of three is obese or morbidly obese. Obesity disproportionally affects African
Americans, who have the highest age-adjusted prevalence of obesity (49.9%). Obesity disparities by race and
geolocation result from complicated interactions between individual behaviors (e.g., physical activities, healthy
food choices) and socioeconomic and environmental context (income, public infrastructure, neighborhood
green lands). Individuals’ obesity-related behaviors are embedded in their communities and shaped by
structural factors (e.g., racial segregation) and built environments (infrastructure and resources). The
obesogenic environment produces conditions that encourage the overconsumption of calories and sedentary
behaviors. For instance, distribution of different food resources (e.g., healthy food grocery stores, fast-food
restaurants) within a residence area may influence people’s food choice and consumption. Likewise,
neighborhoods with few walking or bike trails, poor street lighting, limited public transportation, and a lack of
recreational spaces such as parks hinder physical activity and thus increase obesity risk. Traditional obesogenic
environment indices are limited by a lack of timely monitoring the dynamic utilization of the infrastructures,
challenges in integrating with behavioral data, and the potential bias due to self-report survey. To address
these limitations and better assess and explore racial disparities of obesity, we propose to develop and test a
novel measurement tool to assess obesity-related behaviors at multiple geographic levels (i.e., census
blockgroup, tract, and county) in the US. First, a novel visitation-based obesogenic environment measurement
(VOEM) will be developed using cellphone-based place visitation data to measure three types of obesity-related
behaviors: physical activity (visitation to the exercise facilities such as parks and gyms), healthy food choices
(visitation to healthy food outlets such as supermarkets and organic groceries), and less healthy food choices
(visitation to fast-food restaurants and convenience stores). Second, the validity and performance of the
VOEM will be assessed in terms of predicting adult obesity rates and explaining associated racial disparities at
multiple geographic levels in the US by controlling for population-level social determinants of health and other
sociodemographic factors based on public available datasets. This comprehensive, valid, and near real-time
measurement instrument can be used as a surveillance tool to monitor population-level patterns and changes
of proxy obesity-related behaviors over space and time (e.g., seasonal trends), map obesogenic environments at
various geographic levels, and thus inform tailored and evidence-based policy decision making and public
health strategies for reducing racial disparities of obesity in terms of resource allocation, development of
prevention efforts, and efficacy evaluation of relevant health behavior interventions.
