The effect of a low glycaemic index diet on reducing day‐long glycaemia in healthy young adults: A randomized crossover trial

Abstract

Aim: To compare the effect of a low glycaemic index (LGI) diet on reducing day-long glycaemia with a macronutrient-matched high glycaemic index (HGI) diet, using customized meal delivery to ensure compliance. Materials and Methods: We conducted a single-blinded, randomized crossover trial in 14 healthy adults (57% female) with a mean ± SD age of 21.6 ± 1.7 years. A flash glucose monitoring sensor was installed on the subjects on day 1 to capture the interstitial glucose level every 15 minutes for 14 days. Subjects were randomized to receive an LGI (dietary GI = 40) or HGI (dietary GI = 60) diet (three meals and two snacks) from day 2 for 5 consecutive days, followed by a 2-day washout, then switched to the alternative diet for another 5 days. A paired t-test was used to test the differences in the incremental area under the curve (iAUC) of glucose, postprandial glucose (PPG) concentration and maximum postprandial glucose rise (MPGR) between the LGI and HGI periods. Results: Subjects had lower iAUC for average day-long glycaemia during the LGI intervention period compared with the HGI period (mean ± SD, 865 ± 297 vs. 1024 ± 267 mmol x min/L; P = .047). PPG for breakfast and snack 2, and MPGR for breakfast, snack 2 and dinner, were lower in the LGI period. Conclusions: In young healthy adults, following an LGI diet resulted in lower average day-long glycaemia compared with a macronutrient-matched HGI diet. Our results support the use of LGI diets to reduce the risk of developing glucose intolerance. K E Y W O R D S day-long glycaemia, flash glucose monitoring, glycaemic index, postprandial glycaemia 1 | INTRODUCTION Glycaemic index (GI) is the term introduced by Jenkins et al. 1 to indicate how much the available carbohydrates in foods raised blood glucose on a gram for gram basis. Foods with a higher GI are digested and absorbed in a quicker manner, causing a higher postprandial blood glucose excursion in a shorter duration. 1 The shift from traditional diets that are low GI (LGI) to industrialized diets, which are fibre-depleted, energy-dense and nutrient poor, 2 coincides with a drastic increase in the prevalence of obesity, insulin resistance and cardiovascular diseases. 3 Accumulated evidence from acute and long-term studies has confirmed the health benefits of LGI diets, including but not limited to increased satiety, 4 and improvements in postprandial glycaemia, 5 insulin sensitivity, 6 weight control 4,7 and inflammatory biomarkers. 8

Effects of Spaghetti Differing in Soluble Fiber and Protein Content on Glycemic Responses in Humans: A Randomized Clinical Trial in Healthy Subjects

“…Short-term intervention studies [ 32 ] and epidemiological and prospective studies have consistently shown an association between wholegrain consumption and a reduced mortality and metabolic disease risk [ 33 , 34 ]. A short-term study using continuous glucose monitoring showed that young healthy adults following a low GI diet had lower average day-long glycemia compared with a macronutrient-matched high GI diet, indicating the use of low GI diets to reduce the risk of developing glucose intolerance [ 35 ]. The use of GI for the classification of carbohydrate-rich foods has been endorsed by the FAO/WHO, who recommended that the GI of foods should be considered together with information about food composition to guide food choices [ 2 ].…”

PalatinoseTM (Isomaltulose) and Prebiotic Inulin-Type Fructans Have Beneficial Effects on Glycemic Response and Gut Microbiota Composition in Healthy Volunteers—A Real-Life, Retrospective Study of a Cohort That Participated in a Digital Nutrition Program

“…A systematic reduction of the dietary glycemic index (GI) could be an important approach to improve postprandial glucose response. It has been shown previously that replacing rapidly digestible, high-GI foods by slowly digestible, low-GI foods contributes to reduced postprandial glycemia and insulinemia and lowers glycemic variability (8)(9)(10)(11). Moreover, there is sufficient evidence that a frequent consumption of high-GI foods is associated with an increased risk of cardiometabolic diseases when compared to a diet rich in low-GI foods (12,13).…”