Dietary Intervention for Type 2 Diabetes

(DG3D Trial)

Overseen By Brie Turner-McGrievy, PhD, MS, RD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of South Carolina

Must not be taking: Weight loss medications

Disqualifiers: Pregnancy, Eating disorder, Bariatric surgery, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how different healthy eating patterns can help African American adults manage risk factors for type 2 diabetes. Participants will follow one of three diets: U.S.-Style, Mediterranean, or Vegetarian, each based on the U.S. Dietary Guidelines. The goal is to tailor these eating plans to better fit cultural preferences. Suitable participants have at least three type 2 diabetes risk factors, are overweight or obese, and live in the Columbia, SC area. As an unphased trial, this study offers participants the chance to contribute to research that could lead to more culturally tailored dietary recommendations.

Will I have to stop taking my current medications?

The trial does not specify whether you need to stop taking your current medications. However, you cannot participate if you are currently taking weight loss medications.

Is there any evidence suggesting that this trial's dietary interventions are likely to be safe?

A previous study linked healthy eating habits to better health. Research shows that the U.S.-Style healthy diet is associated with lower risks for type 2 diabetes and improved overall health. People following this diet consumed less unhealthy fats and sodium, benefiting their health.

Regarding the Mediterranean diet, studies have shown it can reduce the risk of developing type 2 diabetes by 23%. This diet emphasizes fruits, seafood, and healthy fats and is well-known for its health benefits.

For the vegetarian diet, a review of studies found a small but positive effect on lowering blood sugar levels, which is important for reducing diabetes risk. This diet focuses on plant-based foods and is associated with a lower chance of developing type 2 diabetes.

Overall, these diets are generally considered safe and easy to follow. They emphasize whole foods and balanced nutrition, which support good health. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these dietary interventions for type 2 diabetes because they offer a lifestyle-based approach that could complement or even reduce the need for medications like metformin or insulin. The US Healthy Diet emphasizes balanced nutrition with a variety of food groups, aiming for a well-rounded intake that aligns with typical American eating habits. The Mediterranean diet stands out by integrating more fruits and seafood, which may promote heart health and weight loss, both critical factors in managing diabetes. Lastly, the Vegetarian diet eliminates meat and seafood, focusing on plant-based proteins and whole grains, which could improve blood sugar control and reduce cardiovascular risks. These diets offer a more holistic approach to managing diabetes, potentially addressing the condition's root causes and promoting overall health.

What evidence suggests that this trial's dietary interventions could be effective for type 2 diabetes?

Research shows that different eating habits can help manage type 2 diabetes. In this trial, participants will follow one of three dietary patterns. One group will adhere to a healthy diet based on USDA guidelines, which can lower blood sugar levels. Another group will follow the Mediterranean diet, rich in fruits, vegetables, and healthy fats, linked to a 23% lower risk of developing type 2 diabetes and improved blood sugar control. The third group will adopt a Vegetarian diet, excluding meat, which can help reduce blood sugar levels and body weight. Each diet focuses on nutritious foods and reduces unhealthy ones to help manage type 2 diabetes. ^{1 5 6 7 8}

Are You a Good Fit for This Trial?

This trial is for African American adults living in Columbia, SC with overweight/obesity and at least three risk factors for type 2 diabetes. Participants should be aged 18-65, have a BMI of 25-49.9, and not suffer from major diseases or conditions like thyroid issues or diabetes. They must commit to attending all sessions and accept random diet assignments.

Inclusion Criteria

Live in the Columbia, SC area

Be willing to be randomized to either condition and be re-randomized if non-responsive

I can attend all required check-ups.

Exclusion Criteria

I am not in a weight loss program nor taking weight loss medications.

Should be free of an eating disorder as screened by the Eating disorder Screen for Primary care [ESP]. (If a participant has an eating disorder, they will be given contact information for the eating disorder clinic at the University of South Carolina)

I have not lost more than 10 pounds in the last 6 months.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are assigned to one of three dietary patterns (U.S.-Style, Mediterranean, or Vegetarian) for 12 weeks to assess dietary quality and T2DM risk factors

12 weeks

Follow-up

Participants are monitored for changes in dietary quality, body weight, and HgbA1c after the intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Dietary Intervention Meetings

Trial Overview The study tests the adoption of three diets based on U.S. Dietary Guidelines over a period of 12 weeks: U.S.-Style, Mediterranean, or Vegetarian. The aim is to tailor these diets culturally for African Americans at risk of type 2 diabetes.

How Is the Trial Designed?

Group I: Vegetarian diet Experimental Treatment 1 Intervention

Participants in this group will be assigned to follow the Vegetarian dietary pattern as presented by the US Dietary Guidelines. As described here https://www.nia.nih.gov/health/usda-food-patterns: This eating pattern contains no meat, poultry, or seafood. Compared with the Healthy U.S.-Style Eating Pattern, it contains more soy products, eggs, beans and peas, nuts and seeds, and whole grains.

Group II: US Healthy Diet Experimental Treatment 1 Intervention

Participants in this group will be assigned to follow the Healthy US dietary pattern as presented by the US Dietary Guidelines. As described here https://www.nia.nih.gov/health/usda-food-patterns: This eating pattern is based on the types and amounts of foods Americans typically consume. The main types of food in this eating pattern include a variety of vegetables; fruits; whole grains; fat-free or low-fat dairy; seafood, poultry, meat, and eggs; and nuts, seeds, and soy products.

Group III: Mediterranean diet Experimental Treatment 1 Intervention

Participants in this group will be assigned to follow the Mediterranean dietary pattern as presented by the US Dietary Guidelines. As described here https://www.nia.nih.gov/health/usda-food-patterns: This eating pattern contains more fruits and seafood and less dairy than the Healthy U.S.-Style Eating Pattern. There is also less calcium and vitamin D because it includes fewer dairy foods.

Who Is Running the Clinical Trial?

University of South Carolina

Lead Sponsor

Trials

233

Recruited

122,000+

Published Research Related to This Trial

In a study of 136 Japanese adults with type 2 diabetes, individualized dietary advice led to a greater reduction in HbA1c levels (-1.1%) compared to conventional dietary advice (-0.7%) over 6 months, indicating its effectiveness in managing blood sugar levels.

Participants receiving individualized advice also made healthier dietary changes, such as reducing energy intake and consumption of sweets and fats, which contributed to improvements in weight and lipid profiles, although these changes were not significantly different from the conventional group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of individualized dietary advice compared with conventional dietary advice for adults with type 2 diabetes: A randomized controlled trial. Omura, Y., Murakami, K., Matoba, K., et al.[2022]

Strong evidence indicates that the total amount of carbohydrates consumed is more crucial for managing diabetes than the specific type of carbohydrate, highlighting the importance of portion control and meal planning.

Nutrition therapy is effective in achieving treatment goals for blood sugar, lipids, and blood pressure in individuals with type 2 diabetes, and ongoing monitoring is essential to evaluate the effectiveness of lifestyle changes and medication adjustments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prioritizing diabetes nutrition recommendations based on evidence. Franz, MJ.[2015]

The Expert Patient Programme (EPP) designed for individuals with Type 2 diabetes did not show any significant improvements in glycaemic control or dietary outcomes compared to individual dietitian appointments in a study of 317 adults.

Despite a slight increase in starch intake among the EPP group, the overall results indicate that the EPP approach was ineffective in promoting healthier eating habits or improving diabetes management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Can peer educators influence healthy eating in people with diabetes? Results of a randomized controlled trial. Cade, JE., Kirk, SF., Nelson, P., et al.[2022]

In a qualitative study involving 21 adults with type 2 diabetes, participants identified various dietary behavior change techniques (BCTs) like problem-solving and self-monitoring that they used to improve their diets after diagnosis.

Participants also recognized that their dietitians employed effective BCTs such as goal setting and providing instructions, suggesting that dietitians can enhance dietary behavior change by utilizing established behavior change taxonomies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Analyzing Dietary Behaviors Self-reported by People With Diabetes Using a Behavior Change Technique Taxonomy. Rigby, RR., Mitchell, LJ., Hamilton, K., et al.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7468821/

Mediterranean Diet Effects on Type 2 Diabetes Prevention ... They observed that the T2D risk was reduced by 23% among individuals who had a maximum or minimum adherence questionnaire score in the Mediterranean diet [19].

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8071242/

Mediterranean Diet and Type 2 Diabetes Mellitus The results showed that the Mediterranean diet has a beneficial effect on total CVD incidence in patients with diabetes, and total myocardial ...

3. bmcnutr.biomedcentral.com bmcnutr.biomedcentral.com/articles/10.1186/s40795-024-00836-y

The effects of Mediterranean diet on cardiovascular risk ... The meta-analysis presented evidence supporting the beneficial effects of the Mediterranean diet on blood pressure, glycemic control, and weight loss.

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1471489221000758

Mediterranean diet in type 2 diabetes: An updated ... A large body of evidence indicates that the Mediterranean diet is effective in preventing diabetes and improving both glycemic control and cardiometabolic ...

5. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2773099

The Mediterranean Diet and Onset of Diabetes Conclusions and Relevance In this cohort study, higher MED intake scores were associated with a 30% relative risk reduction in type 2 diabetes ...

6. cardiab.biomedcentral.com cardiab.biomedcentral.com/articles/10.1186/s12933-023-01999-x

Association between a mediterranean lifestyle and Type 2 ... There is mounting evidence that the Mediterranean diet prevents type 2 diabetes, but little is known about the role of Mediterranean ...

7. sciencedirect.com sciencedirect.com/science/article/pii/S221133552500138X

Long-term outcomes of a Mediterranean diet with or ... The Building Research in Diet and Cognition Trial tested the short and long-term outcomes of an eight-month Mediterranean Diet lifestyle intervention with ...

8. diabetesjournals.org diabetesjournals.org/care/article/34/1/14/27298/Reduction-in-the-Incidence-of-Type-2-Diabetes-With

Reduction in the Incidence of Type 2 Diabetes With the ... Diabetes rates were reduced by 51 and 52% by the consumption of MedDiets supplemented with virgin olive oil or mixed nuts, respectively, ...