Diet Guidelines: 3 diet Patterns (DG3d)
The Diet Guidelines: 3 Diet Patterns study was a one-year intervention among African American adults targeting risk factors of type 2 diabetes. As part of this study, participants were randomized to follow one of three healthy diets that follow the US Dietary Guidelines: a Healthy-US dietary pattern, a Mediterranean dietary pattern, or a Vegetarian dietary pattern. Participants learned how to cook healthy and delicious recipes to enjoy the health benefits from nutritious meals that taste great.
Recruitment for the DG3D study is now closed. At this time, no additional enrollment opportunities are available for participation in the study. If you’d like to be notified about future studies, please complete our research interest form.
Participate
Thank you for your interest in the DG3D study. Recruitment and enrollment for the study are now closed. If you’d like to be notified about future studies, please complete our research interest form. You can also check our list of active studies for other studies from the BRIE Lab.
Research from the DG3D STudy
- Bailey S, Turner-McGrievy GM, Keseko EA, Duncan T, Ward-Johnson D, Davis B, Wilcox S, Friedman DB, Sarzynski MA, Liese AD. The Diet Guidelines: 3 Diets (DG3D) Study protocol of a behavioral teaching kitchen intervention for type-2 diabetes prevention among African American adults. Contemporary Clinical Trials. In press. (https://pubmed.ncbi.nlm.nih.gov/41077220/)
- Turner-McGrievy GM, Wirth MD, Okpara N, Jones M, Kim Y, Wilcox S, Friedman DB, Sarzynski MA, Liese AD. Similar changes in diet quality indices, but not nutrients, among African American participants randomized to follow one of the three dietary patterns of the US Dietary Guidelines: A secondary analysis. Nutrition Research. 2024 Nov;131:27-38. doi: 10.1016/j.nutres.2024.09.005. (https://pubmed.ncbi.nlm.nih.gov/39366028/)
- Turner-McGrievy GM, Wilson MJ, Carswell J, Okpara N, Aydin H, Bailey S, Davey M, Hutto B, Wilcox S, Friedman DB, Sarzynski MA, Liese AD. A 12-week randomized intervention comparing the Healthy US, Mediterranean, and Vegetarian dietary patterns of the US Dietary Guidelines for changes in body weight, hemoglobin A1c, blood pressure, and dietary quality among African American adults. Journal of Nutrition. 2023 Feb;153(2):579-587. (https://pubmed.ncbi.nlm.nih.gov/36894249/)
- Aydin HZ, Okpara N, Dubois KE, Jones MM, Carswell J, Wilcox S, Friedman DB, Liese AD, Turner-McGrievy G. Perceptions of the Three Dietary Patterns of the 2020–2025 United States Dietary Guidelines Among African American Adults After a 12-Week Randomized Intervention Trial to Reduce Type 2 Diabetes Risk: A Qualitative Study. 2025; 17(21):3453. (https://pubmed.ncbi.nlm.nih.gov/41228525/)
Study Benefits
See what other participants have said about participating in our nutrition studies!
Participating in our studies is fun and can be life changing for your health. See what our former participants have said about our studies and working with Dr. Brie and her team.
Meet our nutrition staff and learn more about healthy eating in this segment from News 19 WLTX.
Community Advisory Board

Ashley Page Bookhart
Director of Programs & Rural Outreach, FoodShare South Carolina

Mary Jones, PhD, MPH
Director of Public Health Workforce Development and Adjunct Faculty
USC Arnold School of Public Health

Darrin Thomas
President at Thomas Media Group and Greek Traditions LLC

Ashley Page Bookhart
Director of Programs & Rural Outreach, FoodShare South Carolina
Ashley Page Bookhart is a Program Coordinator on USC’s SNAP-Ed team based out of USC’s Arnold School of Public Health. She works with nonprofits, libraries and food policy council’s providing technical assistance on food system policy, system and environmental change. She currently serves as the Past Immediate Chair of the Columbia Food Policy Committee the first municipal food policy committee in the state. She also serves on the board of directors of Hannah House a local homeless shelter for women and children. Ashley is a proud alumnus of Converse College and University of South Carolina’s Masters of Social Work Program.

Mary Jones, PhD, MPH
Director of Public Health Workforce Development and Adjunct Faculty
USC Arnold School of Public Health
Dr. Mary Jones serves as the Director of Public Health Workforce Development and Adjunct Faculty at the University of South Carolina Arnold School of Public Health. She has worked in the field of Public Health and Healthcare for 20 years and was proud to serve as Project Manager for the DG3D and NEW Soul Studies from 2017-2023. She has worked specifically on minority health research over the last 13 years. Her research and public health experiences include obesity, diabetes, and heart disease prevention, community engagement and organizing, nutrition, health policy, program evaluation, cost effectiveness and health equity.
In other professional capacities, Dr. Jones works towards coalition development and sustainability and fosters collaborations for the translation of research into public health and health care practice via training and education. She has also served as a Health Educator for Prisma Health for 10 years and is certified through Emory University in partnership with the Centers for Disease Control and Prevention as a Healthy Lifestyles Coach. As a faculty member at USC, she has taught and/or currently teaches: Applied Aspects of Human Nutrition; Nutrition and Food Systems Capstone; University 101; Race, Equity and Health; and Perspectives in Public Health.

Darrin Thomas
President at Thomas Media Group and Greek Traditions LLC
Darrin Thomas is a native of Florence, South Carolina and currently resides in Columbia. Mr. Thomas is a graduate of the University Of South Carolina’s Darla Moore School of Business where he received his undergraduate degree in Marketing and Management. Prior to his entrepreneurial career, Xerox Corporation employed Mr. Thomas as a Marketing Representative in Greenville, South Carolina.
In 1991 Mr. Thomas and his former partners Rod Terry and Gerry McCants, founded Black Pages USA, Inc. then Thomas-McCants Media, Inc. and are known throughout the market as Black Pages USA. Black Pages USA promotes minority businesses and provides a print or internet reference guide for consumers, major corporations and the like, who want to take advantage of services and products offered by minority businesses. They also host “Black Expo”, an event designed to give both minority owned businesses and major corporations the opportunity to reach minority consumers in five southeastern markets. Since that time, Mr. Thomas formed Thomas Media Group, LLC headquartered in Columbia, South Carolina focusing on publishing Black Pages directories and hosting Black Expos in Florida and South Carolina. In 2019, Thomas ceased published the printed version of the Black Pages to focus on Black Expo events in the southeast. Thomas Media Group currently operates 3 offices in the Southeastern United States.
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