Postprandial blood glucose response: does the glycaemic index (GI) value matter even in the low GI range?

Bhupinder Kaur,Shalini Ponnalagu,Melvin Koh,Christiani Jeyakumar Henry

doi:10.1038/s41387-020-0118-5

Abstract

A growing body of research over the last decades has shown that diets based on the low glycaemic index (GI) foods reduce the risk of developing diabetes and improve blood glucose control in people with diabetes. The range of inflexion on the glycaemic response of low GI (LGI) foods is an interesting observation that has not been studied by many. LGI 1 (GI 54 ± 3.3) biscuit was formulated using a basic formulation while the LGI 2 (23.8 ± 3.3) biscuits was a modification of LGI 1 recipe, formulated with the inclusion of functional ingredients. Biscuits were formulated to be iso-caloric (kcal/100 g: 521 ± 12). Each participant consumed identical standard meals for lunch and dinner. Biscuits were consumed as breakfast and mid-afternoon snack. Using a randomized, controlled, crossover study, 13 males [(means ± SD) age: 25.3 ± 1.0 years, BMI 21.6 ± 0.5 kg/m2, fasting blood glucose 4.7 ± 0.1 mmol/L] wore continuous glucose monitoring systems (CGMS™) for 3 days for each test session. The postprandial glycaemic response and insulin response were compared within participants. Total iAUC for breakfast and standard dinner were significantly lower for LGI 2 treatment (p < 0.05) than LGI 1 treatment. Second-meal glucose tolerance was observed at the dinner meal. The overall iAUC insulin response over 180 min was significantly lower for LGI 2 biscuits (p = 0.01). The postprandial glycaemic response of two types of biscuits that fall within the low GI classification (GI 24 and 54) differed with LGI 2 biscuits (GI 24) showing a more suppressed postprandial glycaemic response. Our study shows that even within the low GI range, the GI value matters in influencing postprandial glucose.

Highlights

Introduction The prevalence of type2 diabetes (T2D) is on the rise globally[1]
Assessment by continuous glucose monitoring There were no significant differences in the fasting concentrations of glucose prior to the consumption of the low GI (LGI) 1 and LGI 2 biscuits at breakfast (p-value = 0.61)
The incremental glucose peak, incremental area under the curve (iAUC) 0–1 h, 0–2 h and 0–3 h were significantly lower after LGI 2 biscuits compared to the LGI 1 biscuits (p-value < 0.05)

Summary

Introduction

The World Health Organisation estimated that 2.2 million deaths in 2012 were attributed to high blood glucose and related comorbidities, with another 1.5 million directly attributed to diabetes[2]. There have been numerous studies that investigated the relationship between the GI of foods and the subsequent postprandial glycaemic response[5,6,7,8]. The majority of studies investigating the impact of GI on the postprandial glycaemic response generally compare between the low (GI > 55) and high GI (GI < 70) categories. The impact on postprandial glycaemic response between foods classified within the same range i.e. low GI (GI > 55) but with differing GI values (24 and 54) has not been reported

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