Personalized Dietary Management in Type 2 Diabetes

Abstract Hyperglycemia in type 2 diabetes (T2D) is associated with a variety of vascular complications of the disease, but clinical trials of medication regimens designed to achieve near-normal HbA1c have been disappointing and may even increase the risk of adverse outcomes due to polypharmacy. Enhancing behavioral management of

postprandial glycemia can further reduce glycemic exposure and downstream effects without the risks of polypharmacy. Postprandial glycemia is largely driven by dietary intake, but research findings regarding the best dietary approach to limit glycemic exposure are mixed and mostly negative. Studies done, to-date, have used

one-size-fits-all dietary regimens that do not take into consideration the fact that glycemic response is highly individual. In this clinical trial of 255 (85/group) individuals with early-stage T2D, participants will be randomized to: (1) a Social Cognitive Theory-based behavioral lifestyle intervention that includes a one-size-fits-all

Mediterranean ADA diet (hereafter Standardized), (2) Standardized plus personalized dietary guidance to minimize postprandial glycemic response to meals (hereafter Personalized), or (3) a Usual Care Control plus (hereafter UCC). We will compare the groups in terms of mean amplitude of glycemic excursion (MAGE).

Hypothesis MAGEPersonalized< MAGEStandardized < MAGEUCC at 6 months. At each time point we will describe between group differences in HbA1c, β-cell function, and the need to escalate the medication regimen. We also will describe the impact of the interventions on alternative measures of glycemic variability (standard deviation,

Continuous Overall Net Glycemic Action, area under the curve, and frequency of out-of-range and seriously out- of-range glucose values). We will explore the relative contribution of GV and HbA1c to observed changes in β- cell function. The proposed study is an integrative scientific undertaking, reflecting the input of experts in nursing,

the behavioral sciences, computational biology, microbiome, mHealth technology, endocrinology, and nutrition for the development of personalized behavioral counseling to minimize glycemic exposure and disease progression in those with early-stage T2D.