Glycemic profile is improved by High Slowly Digestible Starch diet in type 2 diabetic patients

Abstract

Introduction Considering the dramatically increasing incidence of type 2 diabetes (T2D), decreasing glycemic variability in T2D patients is a key challenge to limit the occurrence of diabetic complications. Diet appears as one potential lever that can be set up above medications. Particularly, the ingestion of foods with a high content in slowly digestible starch (SDS) demonstrated both lower postprandial glycemic and insulin responses in healthy and insulin resistant subjects. This study aimed at designing a full high‐SDS diet by selecting high‐SDS starchy food products and at studying its impact on glycemic response and variability in T2D. Materials and methods This pilot randomized controlled cross‐over study included eight T2D patients (HbA1c = 7.0 ± 0.2%, BMI = 31.7 ± 2.1 kg/m2, treated by Metformin &Sitagliptin) who consumed twice, for one week a controlled diet containing starchy food products screened and selected to be either High (High‐SDS) or Low (Low‐SDS) in SDS, as determined by the SDS in‐vitro method developed by Englyst et al. During each diet period, the glycemic profile was monitored for 6 days using a Continuous Glucose Monitoring System (CGMS). Multiple metrics related to variability and glycemic responses were calculated. Results 222 SDS analyses were realized on commercial food products as consumed. 23 High‐SDS and 20 Low‐SDS food items with associated specific cooking instructions were selected to design two diets consistent with local T2D recommendations. The High‐SDS diet demonstrated a significantly higher SDS content compared to the Low‐SDS diet (61.6 vs 11.6 g/day; p < 0.0001), mainly driven by selected pasta, rice and high‐SDS biscuits (75.6% of the consumed SDS content). The % of total daily energy intake (TDEI) for all macronutrients remained similar between diets (p > 0.05) and the carbohydrate content specifically represented 49 ± 1 % and 47 ± 2 % of the TDEI for High‐SDS and Low‐SDS diets, respectively. With the high‐SDS diet, the Mean Amplitude of Glycemic Excursion, a key parameter of glycemic variability, was significantly decreased (79.6 for Low‐SDS vs 61.6 mg/dL for High‐SDS; p = 0.0067). The significant correlation between the meals SDS contents and various glycemic parameters such as postprandial iAUC, tAUC (up to 180 min) or peak value strengthen this finding (p < 0.05 for all). Discussion It was the first demonstration that a diet including selected starchy food items and cooking recommendations designed to favor products' high SDS content beneficially impacts glycemic profile in T2D subjects. Carefully selecting starchy food may be a simple and valuable tool to improve glycemic control in T2D.