The Dietary Guidelines 3 Diets Study

The U.S. Dietary Guidelines (USDG) form the basis of federal nutrition programs and policy and provide valuable guidance to health initiatives and industries. The updated 2015 USDG moved away from a focus on individual nutrients to a greater focus on dietary patterns. The USDG state that healthy eating goals can be met through a variety of dietary patterns, but present healthy diet in three main ways: 1) Healthy U.S.-Style Eating Pattern, 2) Healthy Mediterranean-Style Eating Pattern, and 3) Healthy Vegetarian Eating Pattern. Currently, US adults are falling short of the nutrition recommendations (fruit/vegetable intake, greens/beans, whole grains, etc.) set forth by the USDG and measured by the Healthy Eating Index (HEI). While the USDG are the basis of nutrition guidelines, the research informing these dietary pattern recommendations has largely been drawn from observational studies among mostly white populations. In addition, there has been very limited cultural tailoring of these dietary patterns that would ensure that these diets are acceptable to diverse populations, in particular, African Americans (AAs) living in the south, who experience a disproportionate burden of chronic disease, especially type 2 diabetes (T2DM). Currently, US adults are not meeting nutrition recommendations (fruit/vegetable, whole grains, etc.) set forth by the USDG and measured by the Healthy Eating Index (HEI).

For the present study, AA adult participants with overweight/obesity and ≥three T2DM risk factors will be recruited to participate in the following aims:

Aim 1: Conduct a 3-month randomized trial among AAs comparing adoption of the 3 dietary patterns [1) US, 2) Med, or 3) Veg] using existing materials from the USDG and examine differences in diet quality (HEI) and T2DM risk factors (weight, HgbA1c).

Aim 2: Drawing on participants' experiences in Aim 1, conduct qualitative work to refine and culturally tailor the dietary pattern intervention for an AA audience.

Inclusion criteria

• 18-65 years of age
• BMI between 25- 49.9 kg/m2
• self-identify as African American
• live in the Columbia, SC area
• be able to attend all monitoring visits
• be willing to be randomized to either condition and be re-randomized if non-responsive
• be free of major health or psychiatric diseases, drug or alcohol dependency, thyroid conditions, diabetes, or pregnancy

Exclusion criteria

• should not be pregnant (or have been pregnant in the last 6 months), anticipating on becoming pregnant in the next 24 months, or currently breastfeeding

o Women who are pregnant should not be pursuing weight loss and should be under the direct care of a physician. Therefore women who are pregnant or who are anticipating they might be pregnant should not participate in this study. If a woman becomes pregnant during the study, she will be advised to consult with her healthcare provider and will be dropped from the weight loss study.

• 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)
• no current participation in a weight loss program or taking weight loss medications (although participants may be trying to lose weight on their own)
• no recent or planned bariatric surgery
• no recent weight loss (>10 lbs in the last 6 months)