Diet Guidelines: 3 diets (DG3d)

Interested in improving your diet and reducing your risk of developing type 2 diabetes…all while eating great?! Then DG3D at the University of South Carolina (UofSC) may be for you. We’re looking for African American adults between the ages of 18 and 70 who can participate in a 1 year, exciting healthy eating and lifestyle study that will conclude with assessments of your diet, weight, and health behaviors. As part of this study, you will be randomized to follow one of three healthy diets that follow the US Dietary Guidelines: a Nutrient-rich dietary pattern, a Mediterranean dietary pattern, or a Plant-powered dietary pattern. You will learn how to cook healthy and delicious recipes here at USC so that you can enjoy the health benefits from nutritious meals that taste great. You can meet our nutrition staff and learn more about healthy eating here.

Learn More


Thank you for your interest in the DG3D study! Enrollment is now OPEN for our 2024 cohort.

If you are interested in participating, please CLICK HERE to submit your application for enrollment.

Upon completion of your application, please allow 7-10 business days for a member of our team to review and contact you regarding next steps.


Participants must meet the following criteria in order to participate:

  • Self-identify as African American
  • Be between the ages of 18-70 years
  • Have a Body Mass Index between 25- 49.9 kg/m2
  • Live in the Columbia, SC area
  • Not currently pregnant
  • Be free of type 2 diabetes
  • Not currently taking prescription medicine to control type 2 diabetes
  • Be able to attend all monitoring visits
  • Be willing to be randomized to either of the three diets
  • Not currently following a vegan, vegetarian, or Mediterranean diet

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

Keith Alexander

Local Businessperson and
Former Educator


Kevin “Big Redd” Felder

Radio executive and host of nationally syndicated Christian hip-hop program The Big Redd Radio Show


Ashley Page Bookhart

SNAP-Ed Program Coordinator
USC Department of Health Promotion, Education and Behavior


Dr. Martin Luther Quick

Author of e-Vangelism: Creating and Implementing a Social Media Ministry for Outreach

Lead pastor at Cumberland United Methodist Church


Beverly Wilson

Co-Founder and Executive Director


Frequently Asked Questions (FAQ)

What is the purpose of this study?

Improving your diet can have a significant impact on your health, but it’s not known which diet can best address health needs. Many nutrition studies in the past have not included African American participants. For this study, we are only recruiting African American adults. We hope to learn from you about which diets work best to help prevent chronic disease and improve body weight.

What’s the study about?

The Diet Guidelines: 3 Diets (DG3D) study is comparing three different diets, as defined by the US Dietary Guidelines and how they impact type 2 diabetes risk factors among African American adult (such as body weight, blood pressure, and hemoglobin A1c). The intervention will last for 1 year and participants will be randomly assigned to follow a Nutrient-Rich diet, Plant-powered diet, or Mediterranean diet and receive cooking classes, recipes, and guidance for following their assigned diet based on culturally-tailored curriculum.

What will I get by participating?

Free cooking classes, recipes, a support system, and lab results at the end of the study.  If you complete the study, you’ll receive $100.00.

How could participating help me?

You may lose weight and reduce your risk of developing type 2 diabetes by being a part of this study. You will receive cooking classes and learn how to prepare healthy meals.

Who can participate in this program?

You must:

  • Be between the ages of 18 – 70 years
  • Self-identify as African American
  • Have a body mass index (BMI) between 25–49.9 kg/m2 (be overweight or obese)
  • Be available to attend all study meetings over a 1 year period.
  • Be willing to be randomized to either of the 3 diet groups (this means you won’t have a choice in which diet you are assigned to)

Is the study only for African Americans?

Yes. You must self-identify as an African American in order to qualify and participate. 

How can I calculate my BMI to know if I qualify for the study?

You can calculate your BMI online with this online calculator:

Can my spouse participate as well?

Only one person per household can participate in the study as a research participant, but you are free to share all your class materials with friends and family.

What commitment is required of me?

This study will last for 1 year and will therefore require a short-term commitment. You will be required to regularly attend virtual classes, lab visits, and to complete a variety of surveys. You will be required to attend classes once a week for 6 months and then every other week for the remaining 6 months. The virtual classes are structured to be about an hour and fifteen minutes.

What will I have to do in the program?

You will attend group classes to learn more about your diet and receive the support you need to adopt healthier eating habits. The classes will include cooking skills, recipe ideas, and guidance for following your assigned diet.

You will have lab visits that involve height and weight measurements, blood pressure, and a non-fasting blood draw via finger stick. The lab visits will be at the following time points: baseline and 6 months and 1 year.

You will also be completing several questionnaires at each time point: baseline, 6 months and 1 year. You will complete the questionnaires at your classes or at your house and be required to complete online dietary recalls at home. The questionnaires will assess demographic information, psychosocial variables (such as stress), and dietary acceptance. The dietary recalls are online surveys that ask you to recall all the meals and beverages you had in the previous 24-hours. You will be directed to an online database that allows you to enter in the foods and drinks you had for the day.

Can I pick what diet group I belong in or what diet I get to eat?

No. Because this study is using random assignment, participants will be randomly assigned to each diet group. You must be willing to be assigned to either of the 3 diets.

What happens if I can’t attend a class?

Please let one of our study coordinators know that you will miss a class and you will be provided with instructions to complete a make-up class. 

What do I do during lab assessments?

You will have your blood drawn (non-fasting) via a finger stick by a phlebotomist at USC’s Prevention Research Center. You will have your body weight, height, blood pressure, waist circumference, and hip circumference measured.

What if I am interested in participating in the study?

Thank you for your interest in the DG3D study! Enrollment is now open for the 2024 cohort.

If you are interested in participating, please CLICK HERE to submit your application for enrollment.

Contact us

Want to learn more about our team? Click here.

Want more information about the study or have questions? Fill out this contact form and someone will be in contact with you.