Hope Bercaw

Date of Award

Spring 2022

Document Type

Open Access Thesis


Epidemiology and Biostatistics

First Advisor

Angela D Liese


Background Hemoglobin A1c (HbA1c) is a clinical measure of glycemic control among people with diabetes and is associated with health outcomes such as cardiovascular disease. It is possible to decrease HbA1c by improving diet, but it is largely unknown which dietary components are most important in targeting glycemic control.

Objective This study aims to examine whether changes in diet quality across diabetes duration, assessed with the 2015-Healthy Eating Index (HEI), are associated with HbA1c in youth and young adults (YYA) with type 1 (T1D) and type 2 diabetes (T2D). Additionally, we aim to assess whether these relationships differ when dietary quality is measured separately for adequacy and moderation components.

Methods 1429 YYA with T1D and 289 YYA with T2D (mean age: 11.6 ± 4.4 years) in the SEARCH for Diabetes in Youth study were invited to 5 study visits and had completed a food frequency questionnaire and a blood draw at least once between 2001 and 2019. Repeated-measures linear mixed-effects analyses were performed to test longitudinal association between changes in HEI scores and HbA1c across diabetes duration as the measure of time.

Results No significant associations were found between HEI scores (total, adequacy, moderation) and HbA1c, however, trends show that dietary improvements do hold potential in reduce HbA1c among people with T1D. Increased consumption of seafood and plant proteins are associated with improved glycemic control among YYA with T1D (β= -0.08, p=0.04). Conversely, dietary improvements among YYA with T2D are associated with unchanged HbA1c.

Conclusion Diet quality improved across time among YYA with diabetes, but we failed to find a significant association with glycemic control, except for seafood and plant proteins for T1D. It is unlikely that a particular food group can alter glycemic control over time, but that a healthful diet incorporating energy balance and sustained healthy choices is the optimal diet for diabetes management.


© 2022, Hope Bercaw

Available for download on Friday, May 31, 2024

Included in

Epidemiology Commons