Effects of GI and content of indigestible carbohydrates of cereal-based evening meals on glucose tolerance at a subsequent standardised breakfast

Abstract

Objective: To evaluate the impact of four low-glycaemic index (GI) and one high-GI cereal-based evening meals on glucose tolerance at a subsequent standardised breakfast. Design: Wheat kernels, barley kernels, spaghetti, spaghetti with added wheat bran and white wheat bread (WWB) were consumed in the evening in a random order at five different occasions. At the subsequent breakfast, blood glucose, serum insulin, plasma short chain fatty acid, plasma free fatty acid (FFA) and breath hydrogen were measured. Setting: The study was performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. Subjects: Fifteen healthy volunteers were recruited. One subject was later excluded owing to abnormal blood glucose values. Results: The blood glucose response (0-120 min) to the standardised breakfast was significantly lower after consuming barley kernels in the evening compared with evening meals with WWB (P ¼ 0.019) or spaghetti þ wheat bran (P ¼ 0.046). There were no significant differences in insulin concentrations at breakfast. Breath hydrogen excretion at breakfast was significantly higher after an evening meal with barley kernels compared with WWB, wheat kernels or spaghetti (P ¼ 0.026, 0.026 and 0.015, respectively), and the concentration of plasma propionate at breakfast was significantly higher following an evening meal with barley kernels compared with an evening meal with WWB (P ¼ 0.041). In parallel, FFA concentrations were significantly lower after barley kernels compared with WWB (P ¼ 0.042) or spaghetti evening meals (P ¼ 0.019). Conclusions: The improved glucose tolerance at breakfast, following an evening meal with barley kernels appeared to emanate from suppression of FFA levels, mediated by colonic fermentation of the specific indigestible carbohydrates present in this product, or, to the combination of the low-GI features and colonic fermentation. Sponsorship: European Commission QLK1-2001-00431 (EUROSTARCH).

Influence of the glycaemic index of an evening meal on substrate oxidation following breakfast and during exercise the next day in healthy women

“…Fasting FFA concentrations were also lower in the LGI trial compared to the HGI trial before the standard test breakfast was consumed. This finding is in agreement with other studies that have investigated the overnight second meal effect (Thorburn et al, 1993;Nilsson et al, 2006). The production of SCFA has been shown to reduce circulating venous FFA concentrations (Wolever et al, 1991).…”

“…However, several factors can alter the glycaemic response to a given food or meal and an important factor is the characteristics of the previous meal. The concept of the second-meal effect has attracted interest in recent years (Liljeberg et al, 1999;Granfeldt et al, 2006;Nilsson et al, 2006) and can be briefly explained as the first of two consecutive CHO loads leading to improved glucose tolerance to the second (Axelsen et al, 1999). Improvements in glucose tolerance at a standard meal have been reported at lunchtime following a low glycaemic index (LGI) breakfast compared to when an energy-matched HGI breakfast is consumed (Liljeberg et al, 1999;Liljeberg and Bjorck, 2000).…”

Muesli with 4 g oat β-glucans lowers glucose and insulin responses after a bread meal in healthy subjects

“…Accordingly, in a recent overnight study (Granfeldt et al, 2004) we showed that an evening meal containing high levels of indigestible carbohydrates (resistant starch and soluble dietary fibre) substantially reduced GI and II of white bread determined at a subsequent breakfast meal compared to an evening meal of white wheat bread. Further, in a follow up study (Nilsson et al, 2006) the same evening meal, boiled barley kernels, gave significantly lower blood glucose response to a white wheat bread breakfast, compared to evening meals with white wheat bread or spaghetti with added wheat bran. A high fermentative activity in the colon may increase the colonic production of short-chain fatty acid including propionic acid, which has been implemented as a moderator of hepatic glucose metabolism (Venter et al, 1990).…”

Effects of GI vs content of cereal fibre of the evening meal on glucose tolerance at a subsequent standardized breakfast

“…A 'second-meal effect' has also been observed from a late evening meal to breakfast the following morning, indicating that low-GI foods may improve glucose tolerance also over a longer time frame (Wolever et al, 1988;Thorburn et al, 1993;Granfeldt et al, 2006;Nilsson et al, 2006). The mechanisms involved probably differ depending on the time period in between the meals, but a prolonged suppression of free fatty acids (FFA) has been implicated, both in the perspective from breakfast to lunch (Wolever et al, 1995;Brighenti et al, 2006), and from an evening meal to breakfast (Thorburn et al, 1993).…”

“…In the perspective from an evening meal to breakfast, low-GI features per se do not seem to be sufficient to elicit a second-meal effect. Instead, available data indicate that certain low-GI cereal or legume products, which in addition are rich in potentially fermentable indigestible carbohydrates, for example, dietary fibre (DF) and resistant starch (RS), may exert overnight benefits on glucose tolerance (Wolever et al, 1988;Thorburn et al, 1993;Granfeldt et al, 2006;Nilsson et al, 2006). Consequently, despite similar and low GI, it has been shown that boiled intact barley kernels consumed in the evening, in contrast to spaghetti Nilsson et al, 2006), were highly efficient in improving glucose tolerance the next morning compared to an evening meal with white wheat bread (WWB).…”