PROJECTS
My research investigates how food choices impact multiple domains of sustainability: nutrition and health outcomes, environmental sustainability, and affordability. Sometimes it's important to evaluate these domains independently, but some of the most exciting research I do looks at how these domains interact.
Impacts of Pulse Consumption on Human Health, Diet Cost, and Environmental Sustainability
Pulses, which include dry peas, lentils, chickpeas, and dry beans, are an important component of healthy diet patterns recommended by the Dietary Guidelines for Americans, which are currently under consideration for re-publication in 2025. At the same time, pulses can be an important part of affordable and environmentally sustainability diet patterns in the US.
Our prior research demonstrates that pulses are nutrient dense, affordable, and low in environmental impact, which suggests that meeting dietary recommendations for pulses may also be an opportunity to meet other societal objectives related to improving access to affordable and environmentally sustainable foods.
The objectives of this project are to:
1) Compare the nutrient density of pulses to other protein foods;
2) Estimate the mean intake of pulses among population subgroups in a nationally representative sample;
3) Evaluate the association between pulse intake and mortality, and;
4) Compare the overall diet quality, diet cost, and environmental impacts of varying levels of pulse intake.
This project is supported by the US Department of Agriculture's Pulse Crop Health Initiative.
Developing a Decision-Support Tool for Tribal Communities in Virginia, Maryland, and North Carolina
Indigenous communities in Virginia, Maryland, and North Carolina face substantial health disparities driven by unequal access to healthy food and lack of community ownership over food production. Indigenous food sovereignty initiatives have not addressed the unique needs of tribal communities in these areas, and this project aims to fill that gap.
We have partnered with Indigenous community organizations and tribal nations to develop a computational tool for our community partners to make decisions about transitioning toward sustainable food production on Indigenous lands. A unique tool will be developed for each tribal nation to reflect tribe-specific concerns and local environmental conditions. This tool will
provide information on the number of people that can be fed a healthy diet from food produced on tribal lands, optimal sites for sustainable food production, amount of land and other agricultural resources needed, and the effects of future climate change scenarios.
The objectives of this project are to:
1) Develop geospatial models to identify suitable tribal lands for sustainable food production;
2) Develop biophysical models to estimate the number of people that can be fed a healthy diet from food grown on Indigenous lands;
3) Develop user-friendly computer software that integrates the geospatial and biophysical models to create a decision-support tool for dissemination to community partners; and
4) Incorporate novel geospatial data into an educational course titled Pilot GIS Training for Native American Tribes in Virginia hosted by the Institute for Integrative Conservation.
This project uses mostly secondary, cross-sectional, publicly available geospatial and survey data collected from US government agencies, and will be supplemented with primary data collected from Indigenous communities using questionnaires and community conversations. To maximize impact, Indigenous communities will play critical roles at each stage of this project to create a circular flow of information that originates from the communities and ultimately feeds back into the communities.
This project is supported by The Jeffress Memorial Trust for Research Advancing Health Equity.
Macronutrient Intakes and Diet Quality for Contemporary Consumer Diets
Nearly one half of Americans have adopted specialized diets in 2020, an increase of five percentage points over the previous year. These diets include Paleo, grain-free, plant-based, low carbohydrate, high protein, and intermittent fasting, among others. Nearly all consumers who report following these diets indicate that weight control and general health improvement are the primary motivators for adopting them, yet there is limited scientific evidence on the comparative healthfulness of these diets.
Approximately 75% of consumers perceive their diets to be healthier than the average person, which indicates that many people over-estimate the quality of their food choices. Our previous research has demonstrated that individuals adhering to the same specialized diet can make widely different food choices, which has consequences for overall diet quality and nutrient adequacy. We have also demonstrated that even modest food substitutions can have meaningful impacts on diet quality and nutrient adequacy, and other research has shown that this “small changes” approach can elicit meaningful health improvements.
Yet there is limited information on the effectiveness of these dietary shifts among the many consumers who have adopted specialized diets, which undermines consumers’ efforts to make evidence-based decisions about their food choices for health improvement.
There is a critical need to quantify the diet quality and nutrient adequacy of individuals consuming popular specialized diets in the US, and to understand how incremental shifts toward recommended eating patterns can improve diet quality and nutrient adequacy.
The hypotheses of this project are
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Shifting from current specialized diets to ideal versions of those diets will increase daily diet quality;
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Individuals consuming specialized diets will be less likely to meet daily macro- and micronutrient recommendations compared to individuals consuming ideal versions of those diets; and
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Individuals consuming specialized diets will be less likely to meet daily food-group recommendations compared to individuals consuming ideal versions of those diets.
This project is supported by the Institute for the Advancement of Food and Nutrition Sciences.
Cardiometabolic Effects of Low Carbohydrate/Healthy Fat Diets
Over one third of adults in the United States have metabolic syndrome, a cluster of conditions that predict for cardiometabolic diseases. Being overweight or obese is a
major risk factor for metabolic syndrome and is a key motivator for millions of people to attempt weight loss using popular specialized diets in the United States.
There are many specialized diets whose recommendations prioritize or avoid certain foods or food groups for achieving weight loss. However, even within the same specialized diet, individuals make widely different food choices with consequences for overall diet quality and nutrient adequacy. Restricted carbohydrate diets are among the most popular contemporary weight loss diets, yet the evidence linking these diets to reduced risk for metabolic syndrome (hyperglycemia, dyslipidemia, hypertension, and waist circumference) and other cardiometabolic outcomes (stroke, heart disease, and type 2 diabetes) is mixed, possibly due to heterogeneity of the fatty acid composition of these diets.
Decades of research have demonstrated a key effect of dietary fatty acid composition is to alter the risk for cardiometabolic diseases. For example, there is strong and consistent evidence that higher intake of many, but not all, saturated fatty acids increase cardiovascular risk. In contrast, evidence continues to accumulate that polyunsaturated fatty acids (particularly linoleic acid-18:2n6, eicosapentaenoic acid-20:5n3, and docosahexaenoic acid-22:6n3) are associated with reduced risk for heart disease, type 2 diabetes, and aspects of the metabolic syndrome. The relationship between monounsaturated fatty acid intake and cardiometabolic outcomes is not well characterized, yet it
appears that increasing monounsaturated fatty acid intake may only have a marginal effect.
Given that restricted carbohydrate diets can vary widely in fatty acid composition, it is critical to understand the relationships between these diets differentiated by fatty acid composition and cardiometabolic outcomes.
The hypotheses of this research are:
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Individuals consuming the daily recommended macronutrient intake will exhibit lower prevalence of adverse cardiometabolic outcomes compared to individuals consuming restricted carbohydrate diets;
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Individuals consuming the daily recommended macronutrient intake will be more likely to meet daily micronutrient recommendations compared to individuals consuming restricted carbohydrate diets; and
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Individuals consuming the daily recommended macronutrient intake will exhibit lower risk of cardiometabolic mortality compared to individuals consuming restricted carbohydrate diets.