The current US Dietary Guidelines recommendations for healthy eating patterns were developed using data from observational studies that included primarily white individuals.  As such, little is known about how these diets (Healthy US, Mediterranean, or vegetarian) would impact the health of African Americans prone to type 2 diabetes.  To determine if there were differences in the physiological responses to these diets in those individuals, Turner-McGrievy and colleagues conducted an intervention study and report their findings in the February 2023 issue of The Journal of Nutrition.

The participants (n = 63, 83% female) were African Americans (18-65 years of age, BMI 25-49.9 kg/m2) exhibiting more than three risk factors for type 2 diabetes mellitus.  They were assigned to one of the three dietary arms of the study, which lasted for 12 weeks.  Measurements at baseline and 12 weeks included weight, HbA1c, blood pressure, and dietary quality.  Materials from the USDG/MyPlate were used to program online courses that the participants attended each week. 

The study completion rates were 81% for the Healthy US, 86% for the Mediterranean, and 70% for the vegetarian eating patterns.  Weight loss within the Healthy US, Mediterranean and vegetarian dietary patterns were significant and averaged 2.4, 2.6 and 2.4 kg, respectively.  There were no differences between groups for changes in HbA1c, systolic blood pressure, diastolic blood pressure, or healthy eating index.  However, with post hoc analyses, the Mediterranean diet participants demonstrated a greater improvement in their healthy eating index than the vegetarian group.  Because all three dietary patterns contributed towards weight loss among African Americans, the authors concluded there were no differences between the responses observed in the three groups.


Turner-McGrievy GM, Wilson MJ, Carswell J, Okpara N, Aydin H, Bailey S, et al.  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, Volume 153, Issue 2, February 2023, Pages 579-587.

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