Changes in serum lipids and postprandial glucose and insulin concentrations after consumption of beverages with beta-glucans from oats or barley: a randomised dose-controlled trial

Reduced viscosity Barley β-Glucan versus placebo: a randomized controlled trial of the effects on insulin sensitivity for individuals at risk for diabetes mellitus

Background

Prior studies suggest soluble fibers may favorably affect glucose/insulin metabolism.

Methods

This prospective, randomized, placebo controlled, double blind, parallel group trial evaluated 50 generally healthy subjects without prior diagnosis of diabetes mellitus (44 completers), who were administered beverages containing placebo (control), lower dose (3 g/d), or higher dose (6 g/d) reduced viscosity barley β-glucan (BBG) extract. Subjects (68% women) mean age 56 years, Body Mass Index (BMI) 32 kg/m² and baseline fasting plasma glucose 102 mg/dl were instructed to follow a weight-maintaining Therapeutic Lifestyle Changes (TLC) diet and consumed three 11 oz study beverages daily with meals for 12 weeks. The four primary study endpoint measures were plasma glucose and insulin [each fasting and post-Oral Glucose Tolerance Testing (OGTT)].

Results

Compared to placebo, administration of 3 g/d BBG over 12 weeks significantly reduced glucose incremental Area Under the Curve (iAUC) measures during OGTT and 6 g/d BBG over 12 weeks significantly reduced fasting insulin as well as the related homeostasis model assessment of insulin resistance (HOMA-IR). Beverages were generally well tolerated with no serious adverse experiences and no significant differences between groups for adverse experiences. Per protocol instruction, subjects maintained body weight.

Conclusions

These findings suggest 6 g/d BBG consumed in a beverage over 12 weeks may improve insulin sensitivity among hyperglycemic individuals with no prior diagnosis of diabetes mellitus, and who experience no change in body weight.

Trial Registration

ClinicalTrials.gov Identifier: NCT01375803.

An oat bran meal influences blood insulin levels and related gene sets in peripheral blood mononuclear cells of healthy subjects

The understanding of how fibre-rich meals regulate molecular events at a gene level is limited. This pilot study aimed to investigate changes in gene expression in peripheral blood mononuclear cells (PBMCs) from healthy subjects after consumption of an oat bran-rich meal. Fifteen subjects (8 men and 7 women, aged 20-28 years) ingested meals with oat bran or a control meal after an overnight fast. Blood samples for analysis of postprandial glucose, insulin and triglyceride concentrations were taken during 3 h, while PBMCs for microarray gene expression profiling from five men and five women were taken before and 2 h after the meal. Analysis of transcriptome data was performed with linear mixed models to determine differentially expressed genes in response either to meal intake or meal content, and enrichment analysis was used to identify functional gene sets responding to meal intake and specifically to oat bran intake. Meal intake as such affected gene expression for genes mainly involved in metabolic stress; indicating increased inflammation due to the switch from fasting to fed state. The oat bran meal affected gene sets associated with a lower insulin level, compared with the control meal. The gene sets included genes involved in insulin secretion and β-cell development, but also protein synthesis and genes related to cancer diseases. The oat bran meal also significantly lowered postprandial blood insulin IAUC compared to control. Further studies are needed to compare these acute effects with the long-term health effects of oat bran.

Meta-analysis of the effect of β-glucan intake on blood cholesterol and glucose levels

OBJECTIVE

A meta-analysis was performed on epidemiologic studies to assess the relation between β-glucan consumption from oats and from barley on blood cholesterol level, triglyceride/triacylglycerol (TGL/TAG) level, and blood glucose level (BGL) in humans. In addition, the effect of β-glucan on total cholesterol (TC) and BGL was translated into an empirical dose-response model.

METHODS

Thirty research articles that evaluated the effect of different exposure levels of β-glucan on blood cholesterol and BGL were analyzed, yielding 126 clinical studies.

RESULTS

There was a significant inverse relation in TC (-0.60 mmol/L, 95% confidence interval [CI] -0.85 to -0.34), low-density lipoprotein (-0.66 mmol/L, 95% CI -0.96 to -0.36), and TGL/TAG (-0.04 mmol/L, 95% CI -0.15 to 0.07) after consumption of β-glucan. In contrast, an increase in high-density lipoprotein cholesterol was noted (0.03 mmol/L, 95% CI -0.06 to 0.13) with the random-effect model. The analysis showed a significant change in BGL (-2.58 mmol/L, 95% CI -3.22 to -1.84) with high heterogeneity between (I(2) = 97%) and across (τ(2) = 5.88) the studies. The fixed-effect model showed a significant change in TC, low-density lipoprotein, and BGL, whereas it showed no significant changes in high-density lipoprotein and TGL/TAG. The dose-response model showed that a 3-g/d dose of oat or barley β-glucan was sufficient to decrease TC.

CONCLUSION

Consumption of 3 g/d of oat or barley β-glucan is sufficient to decrease blood cholesterol, whereas the effect on BGL is still inconclusive, with high heterogeneity, and requires further clinical research studies with longer intervention periods.

Effects of dietary fiber and its components on metabolic health

Dietary fiber and whole grains contain a unique blend of bioactive components including resistant starches, vitamins, minerals, phytochemicals and antioxidants. As a result, research regarding their potential health benefits has received considerable attention in the last several decades. Epidemiological and clinical studies demonstrate that intake of dietary fiber and whole grain is inversely related to obesity, type two diabetes, cancer and cardiovascular disease (CVD). Defining dietary fiber is a divergent process and is dependent on both nutrition and analytical concepts. The most common and accepted definition is based on nutritional physiology. Generally speaking, dietary fiber is the edible parts of plants, or similar carbohydrates, that are resistant to digestion and absorption in the small intestine. Dietary fiber can be separated into many different fractions. Recent research has begun to isolate these components and determine if increasing their levels in a diet is beneficial to human health. These fractions include arabinoxylan, inulin, pectin, bran, cellulose, β-glucan and resistant starch. The study of these components may give us a better understanding of how and why dietary fiber may decrease the risk for certain diseases. The mechanisms behind the reported effects of dietary fiber on metabolic health are not well established. It is speculated to be a result of changes in intestinal viscosity, nutrient absorption, rate of passage, production of short chain fatty acids and production of gut hormones. Given the inconsistencies reported between studies this review will examine the most up to date data concerning dietary fiber and its effects on metabolic health.

Effects of PGX, a novel functional fibre, on acute and delayed postprandial glycaemia

Background:

Viscous fibre in food has established health benefits, but few functional fibre preparations are both effective and palatable. Our objective was to determine the most effective dose, formulation and timing of consumption of a novel fibre supplement (PolyGlycopleX (PGX)) in reducing postprandial glycaemia.

Subjects/methods:

Three trials were undertaken, each with 10 subjects (8M and 8F; age 24.4±2.6 years). Granular supplement was tested at four doses (0, 2.5, 5.0 and 7.5 g) with breakfast (study 1). Granular and capsule forms of the supplement were given in a single dose (5 g for granules and 4.5 g in capsules) at −60, −45, −30, −15 and 0 before, and +15 min after a bread meal (study 2). Capsules at increasing doses (1.5, 3, 4.5 and 6 g) were consumed with the evening meal to determine effects on glucose tolerance at breakfast (study 3). Incremental area under the blood glucose curve was determined.

Results:

Granular PGX at breakfast time at doses of 2.5, 5 and 7.5 g reduced the incremental area under the curve by up to 50% in a linear dose–response fashion (P<0.001). The granular form of PGX (5 g), but not the capsules, reduced glycaemia by up to 28% when consumed from −45 to +15 min (P<0.001). Capsules containing 3, 4.5 and 6 g PGX consumed with the evening meal reduced glycaemia at breakfast by up to 28% (P<0.001).

Conclusions:

PGX has biologically important, dose-related effects on acute and delayed (second meal) postprandial glycaemia.

Physicochemical properties of oat β-glucan influence its ability to reduce serum LDL cholesterol in humans: a randomized clinical trial

BACKGROUND

Consumption of 3 g oat β-glucan/d is considered sufficient to lower serum LDL cholesterol, but some studies have shown no effect. LDL cholesterol lowering by oat β-glucan may depend on viscosity, which is controlled by the molecular weight (MW) and amount of oat β-glucan solubilized in the intestine (C).

OBJECTIVES

Our 2 primary objectives were to determine whether consumption of 3 g high-MW oat β-glucan/d would reduce LDL cholesterol and whether LDL cholesterol lowering was related to the log(MW × C) of oat β-glucan.

DESIGN

In a double-blind, parallel-design, multicenter clinical trial, subjects with LDL cholesterol ≥3.0 and ≤5.0 mmol/L (n = 786 screened, n = 400 ineligible, n = 19 refused, n = 367 enrolled, and n = 345 completed) were randomly assigned to receive cereal containing wheat fiber (n = 87) or 3 g high-MW (2,210,000 g/mol, n = 86), 4 g medium-MW (850,000 g/mol, n = 67), 3 g medium-MW (530,000 g/mol, n = 64), or 4 g low-MW (210,000 g/mol, n = 63) oat β-glucan/d (divided doses, twice daily) for 4 wk.

RESULTS

LDL cholesterol was significantly less with 3 g high-MW, 4 g medium-MW, and 3 g medium-MW oat β-glucan cereals than with the wheat-fiber cereal by 0.21 (5.5%; 95% CI: -0.11, -0.30; P = 0.002), 0.26 (6.5%; 95% CI: -0.14, -0.37; P = 0.0007), and 0.19 (4.7%; 95% CI: -0.08, -0.30; P = 0.01) mmol/L, respectively. However, the effect of 4 g low-MW oat β-glucan/d (0.10 mmol/L) was not significant (2.3%; 95% CI: 0.02, -0.20). By analysis of covariance, log(MW × C) was a significant determinant of LDL cholesterol (P = 0.003). Treatment effects were not significantly influenced by age, sex, study center, or baseline LDL cholesterol.

CONCLUSIONS

The physicochemical properties of oat β-glucan should be considered when assessing the cholesterol-lowering ability of oat-containing products; an extruded breakfast cereal containing 3 g oat β-glucan/d with a high-MW (2,210,000 g/mol) or a medium-MW (530,000 g/mol) lowered LDL cholesterol similarly by ≈0.2 mmol/L (5%), but efficacy was reduced by 50% when MW was reduced to 210,000 g/mol. This trial was registered at www.clinicaltrials.gov as NCT00981981.

In vitro bile-acid binding and fermentation of high, medium, and low molecular weight beta-glucan

The impact of beta-glucan molecular weight (MW) on in vitro bile-acid binding and in vitro fermentation with human fecal flora was evaluated. beta-Glucan extracted from oat line 'N979-5-4' was treated with lichenase (1,3-1,4-beta-D-glucanase) to yield high (6.87x10(5) g/mol), medium (3.71x10(5) g/mol), and low (1.56x10(5) g/mol) MW fractions. The low MW beta-glucan bound more bile acid than did the high MW beta-glucan (p<0.05). If the positive control, cholestyramine, was considered to bind bile acid at 100%, the relative bile-acid binding of the original oat flour and the extracted beta-glucan with high, medium, and low MW was 15, 27, 24, and 21%, respectively. Significant effects of high, medium, and low MW beta-glucans on total SCFA were observed compared to the blank without substrate (p<0.05). There were no differences in pH changes and total gas production among high, medium, and low MW beta-glucans, and lactulose. The low MW beta-glucan produced greater amounts of SCFA than the high MW after 24 h of fermentation. Among the major SCFA, more propionate was produced from all MW fractions of extracted beta-glucans than from lactulose. In vitro fermentation of extracted beta-glucan fractions with different MW lowered pH and produced SCFA, providing potential biological function.

Effects of oats on plasma cholesterol and lipoproteins in C57BL/6 mice are substrain specific

Cholesterol-lowering effects of oats have been demonstrated in both animals and human subjects. However, the crucial properties of oat-containing diets that determine their health effects need to be further investigated to optimise their use. A mouse model would be a valuable tool, but few such studies have been published to date. We investigated the effects of oat bran on plasma cholesterol and lipoproteins in two substrains of C57BL/6 mice. Western diet was made atherogenic by the addition of 0·8 % cholesterol and 0·1 % cholic acid. After 4 weeks on atherogenic diet, total plasma cholesterol had increased from 1·86–2·53 to 3·77–4·40 mmol/l. In C57BL/6NCrl mice, inclusion of 27 and 40 % oat bran reduced total plasma cholesterol by 19 and 24 %, respectively, reduced the shift from HDL to LDL+VLDL and caused increased faecal cholesterol excretion. There was no effect of oat bran on plasma levels of the inflammatory markers fibrinogen, serum amyloid A or TNF-α. Contrary to findings in C57BL/6NCrl mice, there was no sustained effect of oat bran (27 or 40 %) on plasma cholesterol in C57BL/6JBomTac mice after 4 weeks of feeding. Thus, C57BL/6NCrl mice fed an atherogenic diet are a good model for studies of physiological effects of oats, whereas a substrain derived from C57BL/6J, raised in a different breeding environment and likely possessing functional genetic differences from C57BL/6N, is considerably less responsive to oats. The present finding that two substrains of mice respond differently to oats is of practical value, but can also help to elucidate mechanisms of the cholesterol-lowering effect of oats.

The influence of dietary fibre source and gender on the postprandial glucose and lipid response in healthy subjects

BACKGROUND

Consumption of soluble dietary fibre is correlated with decreased postprandial glucose and insulin responses and hence has beneficial effects on the metabolic syndrome.

AIM OF THE STUDY

To investigate the effects on postprandial glucose, insulin and triglyceride concentrations of meals enriched with soluble dietary fibres from oats, rye bran, sugar beet fibre or a mixture of these three fibres.

METHODS

Thirteen healthy human volunteers (6 men and 7 women, aged 20-28 years) were included in the study. The subjects came to the study centre once a week after an overnight fast to ingest test meals and a control meal in random order. The meals contained either oat powder (62 g, of which 2.7 soluble fibre), rye bran (31 g, of which 1.7 g soluble fibre), sugar beet fibre (19 g, of which 5 g soluble fibre), a mixture of these three fibres (74 g, of which 1.7 g soluble fibre from each source, giving 5 g soluble fibre) or no added fibre (control) and were all adjusted to contain the same total amount of available carbohydrates. Blood samples were drawn before and every 30 min up to 180 min after the meals.

RESULTS

Meals with rye bran gave a lower postprandial glucose peak when compared with the control meal, and this effect was more pronounced in women compared to men. Oat powder, containing a low amount of total fibre and a high amount of carbohydrates in liquid matrix, gave a higher incremental glucose peak concentration compared to rye bran and sugar beet fibre and higher insulin incremental area under curve compared to control. The oat powder also influenced the effects of the mixed meal, diminishing the glucose-lowering effects. Postprandial triglyceride levels tended to be higher after all fibre-rich meals, but only significant for oat powder and the mixed meal when compared with the control meal.

CONCLUSIONS

Postprandial glucose, insulin and triglyceride concentrations are influenced by dietary fibre-rich meals, depending on fibre source, dose of soluble and total fibre and possibly gender.

The effects of barley-derived soluble fiber on serum lipids

PURPOSE

We wanted to determine the association between consumption of barley and changes in plasma lipids in healthy and hypercholesterolemic men and women.

METHODS

A systematic literature search was conducted from the earliest possible date through January 2008. Trials were included in the analysis if they were randomized controlled trials of barley that reported efficacy data on at least 1 lipid endpoint. A DerSimonian and Laird random-effects model was used in calculating the weighted mean difference (WMD) and its 95% confidence interval (CI). Statistical heterogeneity was addressed using the I(2) statistic. Visual inspection of funnel plots, Egger's weighted regression statistics, and the trim and fill method were used to assess for publication bias.

RESULTS

We found 8 trials (n = 391 patients) of 4 to 12 weeks' duration evaluating the lipid-reducing effects of barley. The use of barley significantly lowered total cholesterol (weighted mean difference [WMD], -13.38 mg/dL; 95% CI, -18.46 to -8.31 mg/dL), low-density lipoprotein (LDL) cholesterol (WMD, -10.02 mg/dL; 95% CI, -14.03 to -6.00 mg/dL) and triglycerides (WMD, -11.83 mg/dL; 95% CI, -20.12 to -3.55 mg/dL) but did not appear to significantly alter high-density lipoprotein (HDL) cholesterol (P=.07).

CONCLUSION

Barley-derived beta-glucan appears to beneficially affect total cholesterol, LDL-cholesterol, and triglycerides, but not HDL-cholesterol.

Visão retrospectiva em fibras alimentares com ênfase em beta-glucanas no tratamento do diabetes

Fibra alimentar refere-se aos componentes de plantas ou carboidratos análogos que são resistentes à digestão e absorção no intestino delgado humano. A American Dietetic Association recomenda ingestão de 20-35g de fibras ao dia. Evidências sugerem que uma dieta rica em fibras traz benefícios à manutenção da saúde, redução de risco e tratamento de doenças crônicas como a obesidade, doenças cardiovasculares, diverticulite e diabetes. As fibras são classificadas de acordo com a sua solubilidade em solúveis e insolúveis, com efeitos fisiológicos distintos. As insolúveis são responsáveis pelo aumento do bolo fecal e diminuição do tempo de trânsito intestinal. As solúveis retardam o esvaziamento gástrico e a absorção de glicose diminuindo a glicemia pós-prandial e reduzem o colesterol sérico devido à sua característica física de conferir viscosidade ao conteúdo luminal. As beta-glucanas são fibras altamente viscosas e seu consumo está relacionado à atenuação da resposta glicêmica e insulínica pós-prandial. A beta-glucana tem efeito sobre a degradação do amido e sobre o carboidrato disponível e conseqüentemente, sobre o índice glicêmico dos alimentos ingeridos. Recomenda-se sua ingestão com o objetivo de modular a glicemia e a necessidade de insulina, no tratamento da obesidade, doenças cardiovasculares e do diabetes. Este trabalho visa fornecer uma visão geral sobre beta-glucanas no tratamento do diabetes.

Issues surrounding health claims for barley

Government-approved health claims support dietary intervention as a safe and practical approach to improving consumer health and provide industry with regulatory guidelines for food product labels. Claims already allowed in the United States, United Kingdom, Sweden, and The Netherlands for reducing cholesterol through consumption of oat or barley soluble fiber provide a basis for review, but each country may have different criteria for assessing clinical evidence for a physiological effect. For example, the FDA-approved barley health claim was based on a petition that included 39 animal model studies and 11 human clinical trials. Since then, more studies have been published, but with few exceptions, clinical data continue to demonstrate that the consumption of barley products is effective for lowering total and LDL cholesterol. More research is needed to fully understand the mechanism of cholesterol reduction and the role of beta-glucan molecular weight, viscosity, and solubility. In an assessment of the physiological efficacy of a dietary intervention, consideration should also be given to the potential impact of physical and thermal food-processing treatments and genotypic variation in the barley source. New barley cultivars have been generated specifically for food use, possessing increased beta-glucan, desirable starch composition profiles, and improved milling/processing traits. These advances in barley production, coupled with the establishment of a government-regulated health claim for barley beta-glucan, will stimulate new processing opportunities for barley foods and provide consumers with reliable, healthy food choices.

Water-soluble dietary fibers and cardiovascular disease

One well-established way to reduce the risk of developing cardiovascular disease (CVD) is to lower serum LDL cholesterol levels by reducing saturated fat intake. However, the importance of other dietary approaches, such as increasing the intake of water-soluble dietary fibers is increasingly recognized. Well-controlled intervention studies have now shown that four major water-soluble fiber types-beta-glucan, psyllium, pectin and guar gum-effectively lower serum LDL cholesterol concentrations, without affecting HDL cholesterol or triacylglycerol concentrations. It is estimated that for each additional gram of water-soluble fiber in the diet serum total and LDL cholesterol concentrations decrease by -0.028 mmol/L and -0.029 mmol/L, respectively. Despite large differences in molecular structure, no major differences existed between the different types of water-soluble fiber, suggesting a common underlying mechanism. In this respect, it is most likely that water-soluble fibers lower the (re)absorption of in particular bile acids. As a result hepatic conversion of cholesterol into bile acids increases, which will ultimately lead to increased LDL uptake by the liver. Additionally, epidemiological studies suggest that a diet high in water-soluble fiber is inversely associated with the risk of CVD. These findings underlie current dietary recommendations to increase water-soluble fiber intake.

Effect of commercial breakfast fibre cereals compared with corn flakes on postprandial blood glucose, gastric emptying and satiety in healthy subjects: a randomized blinded crossover trial

Background

Dietary fibre food intake is related to a reduced risk of developing diabetes mellitus. However, the mechanism of this effect is still not clear. The aim of this study was to evaluate the effect of commercial fibre cereals on the rate of gastric emptying, postprandial glucose response and satiety in healthy subjects.

Methods

Gastric emptying rate (GER) was measured by standardized real time ultrasonography. Twelve healthy subjects were assessed using a randomized crossover blinded trial. The subjects were examined after an 8 hour fast and after assessment of normal fasting blood glucose level. Satiety scores were estimated and blood glucose measurements were taken before and at 0, 20, 30, 40, 60, 80, 100 and 120 min after the end of the meal. GER was calculated as the percentage change in the antral cross-sectional area 15 and 90 min after ingestion of sour milk with corn flakes (GER1), cereal bran flakes (GER2) or wholemeal oat flakes (GER3).

Results

The median value was, respectively, 42% for GER1, 33 % for GER2 and 51% for GER3. The difference between the GER after ingestion of bran flakes compared to wholemeal oat flakes was statistically significant (p = 0.023). The postprandial delta blood glucose level was statistically significantly lower at 40 min (p = 0.045) and 120 min (p = 0.023) after the cereal bran flakes meal. There was no statistical significance between the areas under the curve (AUCs) of the cereals as far as blood glucose and satiety were concerned.

Conclusion

The result of this study demonstrates that the intake of either bran flakes or wholemeal oat flakes has no effect on the total postprandial blood glucose response or satiety when compared to corn flakes. However, the study does show that the intake of cereal bran flakes slows the GER when compared to oat flakes and corn flakes, probably due to a higher fibre content. Since these products do not differ in terms of glucose response and satiety on healthy subjects, they should be considered equivalent in this respect.

Trial registration

ISRCTN90535566

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

OBJECTIVE

To evaluate the impact of an extruded muesli product based on beta-glucan-rich oat bran on postprandial glycaemia and insulinaemia.

SUBJECT/DESIGN

The study is divided in two series. Blood glucose and serum insulin responses were studied after subjects consuming test meals including a serving of muesli with 3 g (series 1) and 4 g (series 2) of beta-glucans, respectively. The muesli was a component in a single serving packet with muesli and yoghurt. This was served together with white wheat bread in the morning after an overnight fast. The compositions were standardized to contain 50 g available carbohydrates. As a reference meal a serving packet without beta-glucans was included. The study was performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. Nineteen and thirteen healthy volunteers with normal body mass index were recruited for series 1 and 2, respectively.

RESULTS

Muesli with 3 g of beta-glucans, included in a mixed bread meal, gave no significant differences in glycaemic response compared to a reference meal without muesli and beta-glucans. In contrast, muesli with 4 g of beta-glucans significantly (P<0.05) lowered the glucose and insulin responses compared to the reference meal.

CONCLUSIONS

Muesli enriched with 4 g of beta-glucans reduces postprandial glucose and insulin levels to a breakfast based on high glycaemic index products. A total of 4 g of beta-glucans from oats seems to be a critical level for a significant decrease in glucose and insulin responses in healthy people.

Effects of meals with high soluble fibre, high amylose barley variant on glucose, insulin, satiety and thermic effect of food in healthy lean women

OBJECTIVE

To examine the effect of barley flour (barley cultivar, Hordeum Vulgare var Himalaya 292) incorporated into breakfast and lunch compared with otherwise identical meals containing white wheat flour on the thermic effect of food (TEF), subsequent food intake and metabolic parameters.

DESIGN

Randomized single blinded crossover study.

SETTING

Outpatient setting.

SUBJECTS AND METHODS

Fourteen healthy women consumed a test breakfast at 0700 h. Energy expenditure, respiratory quotient (RQ), appetite ratings using a visual analogue scale (VAS), insulin and glucose levels were measured before and after a test lunch at 1330 h. Food intake was recorded for the remainder of the day.

RESULTS

The TEF was 5% for both test lunches and meal type did not affect any variable measured by the VAS. There was an increase in post-prandial RQ above baseline (0.80) independent of treatment (0.88 and 0.90 for barley and wheat-containing meals, respectively, P<0.001). Mean area under the glycaemic response curve (AUC) for wheat-containing meals was 4.68+/-1.67 mmol/l/h, 22% higher than for the barley-containing meals (3.67+/-1.91 mmol/l/h), P=0.05. AUC of insulin in response to wheat-containing meals (78.1+/-35.3 mIU/l/h) was 32% greater than barley-containing meals (52.8+/-24.7 mU/l/h), P<0.02. Ad libitum food intake over the next 10 h was reduced by 23% (9.6 vs 11.0 MJ, P<0.05) after the wheat-containing meals compared to the barley-containing glycaemic index meals.

CONCLUSION

Inclusion of an ingredient containing increased soluble fibre and amylose did not reduce spontaneous food intake but rather was associated with higher subsequent energy intakes despite its reduced glycaemic and insulinemic effects.

SPONSORSHIP

CSIRO, Human Nutrition, Adelaide, Australia.