Degree of Food Processing Is Associated With Glycemic Control in African American Adults With Type 2 Diabetes: Findings From Texas Strength Through Resilience in Diabetes Education Clinical Trial.

Background: Type 2 diabetes mellitus (T2DM) disproportionately affects African American (AA) populations. Despite the importance of diet in diabetes management, the association of diet quality and/or the degree of food processing with glycemic control in AA adults with T2DM remains unclear.

Objective: This study aimed to examine associations between diet quality scores and the degree of processing in the diet with glycosylated hemoglobin (HbA1c) level in AA adults with T2DM.

Design: This cross-sectional study used baseline data from participants in Texas Strength Through Resilience in Diabetes Education, an ongoing clinical trial.

Participants/setting: Participants involved in this analysis (N = 273) were AA adults with T2DM recruited through local churches in Austin, TX, and the surrounding areas from August 2020 through April 2023.

Main Outcome Measures: Participants provided 2 24-hour dietary recalls (1 weekend and 1 weekday) and a blood sample to measure HbA1c level. Healthy Eating Index 2015, Alternative Healthy Eating Index 2010, and Alternate Mediterranean Diet scores were calculated. The NOVA method was used to calculate the percentage of grams and calories that came from ultraprocessed foods and unprocessed or minimally processed foods.

Statistical Analyses Performed: Linear regression and analysis of variance models tested associations between the diet quality scores and degree of food processing with HbA1c level, adjusting for demographic covariates. Models were stratified by insulin use after finding a significant interaction with ultraprocessed foods and unprocessed or minimally processed foods.

Results: Regression analyses revealed that the percentage of grams in the total diet from ultraprocessed foods was positively associated with HbA1c level (β = .015; P = .032), whereas unprocessed or minimally processed foods were inversely associated with HbA1c level (β = -.014; P = .043). There was no significant association between any diet quality score and HbA1c level.

Conclusions: In AA adults with T2DM, only the degree of food processing was associated with HbA1c level. Future research should explore whether a causal relationship exists between food processing and HbA1c level and investigate mechanisms by which ultraprocessed foods may affect glycemic control.