Comparable effects of breakfast meals varying in protein source on appetite and subsequent energy intake in healthy males.

PURPOSE: The satiating effect of animal vs plant proteins remains unknown. The present study examined the effects of breakfasts containing animal proteins [milk (AP)], a blend of plant proteins [oat, pea and potato (VP)] or 50:50 mixture of the two (MP) compared with a carbohydrate-rich meal (CHO) on appetite, energy intake (EI) and metabolic measures. METHODS: A total of 28 males [mean age 27.4 (±SD 4.2) years, BMI 23.4 (±2.1) kg/m2] consumed three isoenergetic (1674 kJ) rice puddings matched for energy density and macronutrient content as breakfast (25% E from protein) in a single-blind, randomised, cross over design. Appetite ratings and blood samples were collected and assessed at baseline and every 30 and 60 min, respectively, until an ad libitum test meal was served 3.5 h later. Free-living appetite was recorded hourly and EI in weighed food records for the remainder of the day. RESULTS: No differences in subjective appetite ratings were observed after consumption of the AP, VP and MP. Furthermore, there were no differences between the AP, VP, MP and CHO breakfasts in ad libitum EI and self-reported EI during the remainder of the day. Although insulin metabolism was not affected, CHO induced a higher glucose response (P = 0.001) and total amino acids concentration was in the order of AP = MP > VP > CHO breakfast (P = 0.001). CONCLUSION: Manipulating the protein source of foods consumed as breakfast, elicited comparable effects on appetite and EI at both laboratory and free-living environment in healthy men.

Protein-Enriched Liquid Preloads Varying in Macronutrient Content Modulate Appetite and Appetite-Regulating Hormones in Healthy Adults.

BACKGROUND: Dietary protein is considered the most satiating macronutrient, yet there is little evidence on whether the effects observed are attributable to the protein or to the concomitant manipulation of carbohydrates and fat. OBJECTIVE: The aim was to examine the effect of consumption of preloads varying in macronutrient content on appetite, energy intake, and biomarkers of satiety. METHODS: Using a randomized, within-subjects, 2-level factorial design, 36 adults [mean ± SD age: 27 ± 5 y; body mass index (in kg/m(2)): 24.3 ± 1.6) received a breakfast consisting of 1 of 7 isovolumetric (670 mL) and isoenergetic (2100 kJ) liquid preloads matched for energy density and sensory properties but with different macronutrient composition (levels: 9%, 24%, or 40% of energy from protein combined with a carbohydrate-to-fat ratio of 0.4, 2, or 3.6, respectively). Appetite ratings and blood samples were collected and assessed at baseline and every 30 and 60 min, respectively, until a lunch test meal, which participants consumed ad libitum, was served 3.5 h after breakfast. RESULTS: Prospective consumption was 12% lower after intake of the high-protein (40%)/3.6 carbohydrate:fat preload than after intake of the low-protein (9%)/0.4 carbohydrate:fat preload (P = 0.02) solely because of the increased protein, irrespective of the manipulation of the other macronutrients. Most appetite ratings tended to be suppressed (13%) with increasing protein content of the preloads (P < 0.06). Carbohydrate elicited greater increases in fullness and postprandial responses of glucose and insulin than did protein and fat. The glucose concentration was suppressed and glucagon-like peptide 1 increased more after intake of the high-protein (40%)/0.4 carbohydrate:fat preload than after the other preloads (P < 0.001). No statistically significant differences in postprandial ghrelin release or ad libitum energy intake at lunch were found. CONCLUSIONS: By varying all 3 macronutrients simultaneously and in a systematically balanced manner, we found that protein had a more pronounced effect on suppressing appetite than did carbohydrates and fat. Modulating the nutritional profile of a meal by replacing fat with protein can influence appetite in healthy adults. This trial was registered at www.clinicaltrials.gov as NCT01849302.

Impact of Diet Composition on Blood Glucose Regulation.

Nutritional management of blood glucose levels is a strategic target in the prevention and management of type 2 diabetes mellitus (T2DM). To implement such an approach, it is essential to understand the effect of food on glycemic regulation and on the underlying metabolic derangements. This comprehensive review summarizes the results from human dietary interventions exploring the impact of dietary components on blood glucose levels. Included are the major macronutrients; carbohydrate, protein and fat, micronutrient vitamins and minerals, nonnutrient phytochemicals and additional foods including low-calorie sweeteners, vinegar, and alcohol. Based on the evidence presented in this review, it is clear that dietary components have significant and clinically relevant effects on blood glucose modulation. An integrated approach that includes reducing excess body weight, increased physical activity along with a dietary regime to regulate blood glucose levels will not only be advantages in T2DM management, but will benefit the health of the population and limit the increasing worldwide incidence of T2DM.

Effects of wheat bran extract rich in arabinoxylan oligosaccharides and resistant starch on overnight glucose tolerance and markers of gut fermentation in healthy young adults.

PURPOSE: Specific combinations of dietary fiber (DF) have been observed to result in improved glucose tolerance at a subsequent standardized breakfast. Arabinoxylan oligosaccharides (AXOS) are considered as DF with prebiotic potential, but so far no studies have investigated their metabolic effects in humans. This randomized cross-over study evaluated the overnight impact of breads containing AXOS-rich wheat bran extract and resistant starch (RS, Hi-Maize), separately or combined, on glucose tolerance, related metabolic parameters and markers of gut fermentation in healthy subjects. METHODS: Evening reference and test products were: (1) reference white wheat flour bread (WWB), WWB supplemented with (2) AXOS and RS (WWB + AXOS + RS), (3) an increased content of either AXOS (WWB + hiAXOS) or (4) RS (WWB + hiRS). At the subsequent standardized breakfast, blood was sampled for 3 h to monitor glucose, insulin, nonesterified fatty acids, glucagon-like peptide (GLP)-1 and GLP-2. Breath hydrogen (H2) and short chain fatty acids (SCFA) were measured as markers of gut fermentation, and subjective appetite was rated using visual analog scales. RESULTS: Dose-dependent decreases in glucose responses were observed with increased AXOS over the duration of 3 h. Insulin sensitivity index was improved in the morning after the WWB + hiAXOS evening meal. An increase in breath H2 concentration and circulating SCFA was observed in the morning after both evening meals containing AXOS. CONCLUSION: The present study indicates that AXOS have the potential of improving glucose tolerance in an overnight perspective and suggested mechanisms are improved insulin sensitivity and increased gut fermentation.

The impact of liquid preloads varying in macronutrient content on postprandial kinetics of amino acids relative to appetite in healthy adults.

The underlying mechanisms for the effect of proteins on appetite regulation, especially in presence of variable macronutrient composition, are not fully elucidated. The present study investigated the absorption kinetics of proteins after co-ingestion with the other macronutrients and examined the impact of circulating amino acids on appetite and satiety-related gut hormones. A randomized, within-subjects, 2-level full factorial design was implemented, where thirty six healthy subjects consumed seven preloads with similar energy density (3.1 kJ/g) and volume (670 mL) but with varying macronutrient content. The energy from protein (%) and the CHO:fat ratio were the two factors combined in three levels of 9, 24, 40 and 0.4, 2, 3.6 respectively. Blood and appetite parameters were evaluated until the serving of the ad libitum lunch after 210 min and the amino acid concentrations were measured in a subgroup of seven male subjects. The amino acid concentrations peaked at 90 min after all preloads and returned to the baseline values until 210 min. Protein intake affected amino acid profiles (P < 0.05), while no differences (P > 0.05) were detected between the two high protein preloads despite the different CHO:fat ratio (40%/0.4 CHO:fat and 40%/3.6 CHO:fat), indicating that neither carbohydrate nor fat influenced the profiles. Most of the amino acids were not related to appetite sensations or gut hormones (P > 0.05), while glutamate was positively associated with prospective consumption and inversely related to ghrelin (P < 0.05). Valine, leucine, isoleucine, lysine and α-aminobutyric acid were inversely associated with energy intake (P < 0.05). Overall, postprandial amino acid profiles were solely affected by protein content and were not consistently related to appetite regulation. Further investigation of glutamate's effect on appetite is needed.

An oat bran-based beverage reduce postprandial glycaemia equivalent to yoghurt in healthy overweight subjects.

An acute meal study was performed to determine postprandial glucose and insulin responses after consumption of two fermented oat bran-based beverages (with and without exopolysaccharides) and yoghurt. This randomized, single-blind, within-subject study included 18 healthy, overweight participants. Four breakfast meals, including a reference meal, were tested; all meals contained 50 g of available carbohydrates, but differed in energy and macronutrient composition. All experimental meals reduced the postprandial glucose response compared with the reference meal. The oat drinks as well as the yoghurt elicited higher early (0-15 min) insulin responses, but the overall insulinaemia were similar to the reference meal. A new food product containing fermented liquid oat bran and milk reduced the postprandial blood glucose response as efficiently as yoghurt after a high-glycaemic index white wheat bread meal, but the presence of microbial exopolysaccharides did not affect the outcome.

Effects of indigestible carbohydrates in barley on glucose metabolism, appetite and voluntary food intake over 16 h in healthy adults.

BACKGROUND: Recent knowledge in animals suggests that gut microbial metabolism may affect host metabolism, including appetite regulating hormones. The aim of the present study was to evaluate the potential effects of a whole grain barley kernel product, rich in intrinsic indigestible carbohydrates (dietary fibre and resistant starch), on markers of metabolism and appetite regulation in healthy subjects. METHODS: Boiled barley kernels (BK) or white wheat bread (WWB; reference) were provided as late evening meals to 19 young adults in random order using a cross-over design. During subsequent ad libitum standardized breakfast and lunch meals (10.5-16 h), blood was collected for analysis of glucose, plasma insulin, adiponectin, ghrelin, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), serum free fatty acids (FFA) and interleukin (IL)-6. In addition, appetite sensations, voluntary energy intake and breath H2 were determined. RESULTS: BK as evening meal increased plasma GLP-1 at fasting (P < 0.05) and during the experimental day (P < 0.01) compared with WWB. In addition the BK evening meal decreased fasting serum FFA (P < 0.05) and tended to decrease fasting serum IL-6 (P = 0.06). At lunch, preceded by BK evening meal, voluntary energy intake was decreased (P < 0.05) when compared to WWB evening meal. The BK evening meal decreased incremental blood glucose area (P < 0.01), promoted higher breath H2 (P < 0.001), maintained adiponectin concentrations (P < 0.05) and reduced perceived hunger (P < 0.05) during 10.5-16 h after the meal. CONCLUSIONS: The results indicate that the BK evening meal, facilitate glucose regulation, increase the release of GLP-1, reduce subsequent energy intake while at the same time decreasing hunger over 2 subsequent meals, and reduce fasting FFA the subsequent morning, possibly mediated through gut microbial fermentation of the indigestible carbohydrates.

The glycemic, insulinemic and plasma amino acid responses to equi-carbohydrate milk meals, a pilot- study of bovine and human milk.

BACKGROUND: Dairy proteins, in particular the whey fraction, exert insulinogenic properties and facilitate glycemic regulation through a mechanism involving elevation of certain plasma amino acids, and stimulation of incretins. Human milk is rich in whey protein and has not been investigated in this respect. METHOD: Nine healthy volunteers were served test meals consisting of human milk, bovine milk, reconstituted bovine whey- or casein protein in random order. All test meals contributed with 25 g intrinsic or added lactose, and a white wheat bread (WWB) meal was used as reference, providing 25 g starch. Post-prandial levels in plasma of glucose, insulin, incretins and amino acids were investigated at time intervals for up to 2 h. RESULTS: All test meals elicited lower postprandial blood glucose responses, expressed as iAUC 0-120 min compared with the WWB (P < 0.05). The insulin response was increased following all test meals, although only significantly higher after whey. Plasma amino acids were correlated to insulin and incretin secretion (iAUC 0-60 min) (P ≤ 0.05). The lowered glycemia with the test meals (iAUC 0-90 min) was inversely correlated to GLP-1 (iAUC 0-30 min) (P ≤ 0.05). CONCLUSION: This study shows that the glycemic response was significantly lower following all milk/milk protein based test meals, in comparison with WWB. The effect appears to originate from the protein fraction and early phase plasma amino acids and incretins were involved in the insulin secretion. Despite its lower protein content, the human milk was a potent GLP-1 secretagogue and showed insulinogenic properties similar to that seen with reconstituted bovine whey-protein, possibly due to the comparatively high proportion of whey in human milk.

Continuous glucose monitoring as a close to real life alternative to meal studies - a pilot study with a functional drink containing amino acids and chromium.

This pilot study aimed to evaluate a continuous glucose monitoring (CGM) based approach to study the effects of a functional drink containing specific amino acids and chromium picolinate (FD) and a combination of FD with a juice (FDJ) on postprandial glucose in a close to real life setting. The predefined primary endpoint for this study was the 120-min incremental area under the glucose curve (iAUC0-120min ) after meals. It was estimated that using CGM and repeated meals in 6 participants could be sufficient to match the power of the previous study in regards to the quantity of meals. Participants followed a pre-specified meal schedule over 9 days and consumed the drinks three times daily with main meals. Differences between drinks were analyzed by analysis of covariances (ANCOVA) with subject number and activity as random factors and nutrient composition as covariates. In 156 meals available for analysis, a significant 34% reduction of glucose iAUC0-120min was shown for FDJ (p < 0.001). FD did not show a significant effect on its own, but a significant reduction of 17.6% (p = 0.007) was shown in pooled data for FD and FDJ. While the differences between the two functional drinks used were not the primary focus of this study, it was sufficiently powered to detect previously described effects in 60 participants in a cross-over design under laboratory settings. The design presented defines a novel and cost-effective approach using CGM devices and app-based lifestyle tracking for studying nutritional effects on glucose at home in a close to real-life setting.

Effects of cereal breakfasts on postprandial glucose, appetite regulation and voluntary energy intake at a subsequent standardized lunch; focusing on rye products.

BACKGROUND: Rye products have been demonstrated to lower the acute insulin demand, induce a low and prolonged blood glucose response (high Glycemic Profile, GP) and reduce subclinical inflammation. These products may therefore contribute to a lowered risk of obesity, type 2 diabetes and cardio vascular disease. The objective of the present paper was to evaluate the mechanism for a reduced postprandial insulin demand with rye products, and to explore possible appetite regulating properties. METHODS: 10 healthy subjects were served breakfast meals (50 g of available starch) with endosperm- or whole grain rye breads, with and without lactic acid, boiled whole grain rye- (RK) or wheat (WK) kernels, or white wheat bread reference (WWB) in random order in a cross-over design. Plasma concentrations of glucose, ghrelin, serum insulin, free fatty acids, adiponectin, breath hydrogen excretion (H(2)), and subjective satiety was evaluated during the postprandial phase. 270 min after the breakfast, an ad lib lunch buffet was served and the voluntary energy intake (EI) was registered. RESULTS: All rye products and WK induced lower insulinemic indices (II) than WWB. A lower incremental insulin peak following breakfast correlated with a lower EI at lunch (r = 0.38). A low II was related to improved satiety in the early postprandial phase (fullness AUC 0-60 min, r = -0.36). RK induced a higher GP compared to WWB and WK. A higher GP was related to a lowered desire to eat before lunch (AUC 210-270) and to a lower concentration of ghrelin in the late postprandial phase after breakfast (270 min), r = -0.29 and -0.29), which in turn was related to a lower voluntary EI (r = 0.43 and 0.33). The RK breakfast improved satiety in the early postprandial phase (0-60 min) compared to WWB, and induced a lower EI at lunch (-16%). A high content of indigestible carbohydrates in the breakfast products was related to improved satiety (0-60 min, r = 0.68 for fullness), and a higher breath H(2) in the late postprandial phase (120-270 and 270-390 min, r = 0.46 and 0.70). High H(2) (AUC 120-270 min) also correlated with lower EI (r = -0.34). CONCLUSIONS: Rye products, rich in indigestible carbohydrates, induce colonic fermentation already post the breakfast meal, and lowers acute insulin responses. A high excretion of breath H(2) also correlated with a higher GP. Especially, rye kernels induced a high GP which was associated with a 16% lowering of energy intake at a subsequent lunch meal. The bulking effect of rye fiber, colonically derived fermentation metabolites, a high GP and a low insulin response possibly all contributes to the benefits on glucose- and appetite regulation seen in an acute and semi-acute perspective.

A cereal-based evening meal rich in indigestible carbohydrates increases plasma butyrate the next morning.

Epidemiological studies have shown an inverse relation between a whole grain consumption and risk of type-2 diabetes and cardiovascular disease. One tentative mechanism relates to colonic metabolism of indigestible carbohydrates. In a previous study, we reported a positive relation between colonic fermentation and improved glucose tolerance. This work can be seen as an extension of that study, focusing on the tentative role of specific colonic metabolites, i.e. SCFA. Plasma concentrations of acetate, propionate, and butyrate were determined in the morning in healthy participants (5 women and 10 men, mean ± SD: 25.9 ± 3.2 y, BMI < 25) following 8 different cereal-based evening meals (50 g available starch) varying in content of indigestible carbohydrates. Each participant consumed all test meals in a random order on separate evenings. At a standardized breakfast following evening test meals, the postprandial glucose response (incremental area under the curve, 0-120 min) was inversely related to plasma butyrate (r = -0.26; P < 0.01) and acetate (r = -0.20; P < 0.05) concentrations. Evening meals composed of high-amylose barley kernels or high-ß-glucan barley kernels resulted in higher plasma butyrate concentrations the following morning compared with an evening meal with white wheat bread (P < 0.05). The results support the view that cereal products rich in indigestible carbohydrates may improve glucose tolerance through a mechanism involving colonic fermentation and generation of SCFA, where in particular butyric acid may be involved. This mechanism may be one explanation by which whole grain is protective against type 2 diabetes and cardiovascular disease.

A novel nutritional supplement containing amino acids and chromium decreases postprandial glucose response in a randomized, double-blind, placebo-controlled study.

High postprandial blood glucose levels are associated with increased mortality, cardiovascular events and development of diabetes in the general population. Interventions targeting postprandial glucose have been shown to prevent both cardiovascular events and diabetes. This study evaluates the efficacy and safety of a novel nutritional supplement targeting postprandial glucose excursions in non-diabetic adults. Sixty overweight healthy male and female participants were recruited at two centers and randomized in a double-blind, placebo-controlled, crossover design. The supplement, a water-based drink containing 2.6g of amino acids (L-Leucine, L-Threonine, L-Lysine Monohydrochloride, L-Isoleucine, L-Valine) and 250 mcg of chromium picolinate, was consumed with a standardized carbohydrate-rich meal. The primary endpoint was the incremental area under the curve (iAUC) for venous blood glucose from 0 to 120 minutes. Secondary endpoints included glucose iAUC 0-180 minutes and the maximum glucose concentration (Cmax), for both venous and capillary blood glucose. In the intention-to-treat-analysis (n = 60) the supplement resulted in a decreased venous blood glucose iAUC0-120min compared to placebo, mean (SE) of 68.7 (6.6) versus 52.2 (6.8) respectively, a difference of -16.5 mmol/L•min (95% CI -3.1 to -30.0, p = 0.017). The Cmax for venous blood glucose for the supplement and placebo were 6.45 (0.12) versus 6.10 (<0.12), respectively, a difference of -0.35 mmol/L (95% CI -0.17 to -0.53, p<0.001). In the per protocol-analysis (n = 48), the supplement resulted in a decreased Cmax compared to placebo from 6.42 (0.14) to 6.12 (0.14), a difference of -0.29 mmol/L (95% CI -0.12 to -0.47, p = 0.002). No significant differences in capillary blood glucose were found, as measured by regular bed-side glucometers. The nutritional supplement drink containing amino acids and chromium improves the postprandial glucose homeostasis in overweight adults without diabetes. Future studies should clarify, whether regular consumption of the supplement improves markers of disease or could play a role in a diet aiming at preventing the development of diabetes.

Endosperm and whole grain rye breads are characterized by low post-prandial insulin response and a beneficial blood glucose profile.

BACKGROUND: Rye products have previously been shown to induce comparatively low post-prandial insulin responses; irrespectively of their glycaemic indices (GI). However, the mechanism behind this lowered insulin demand remains unknown. An improved insulin economy might contribute to the benefits seen in epidemiological studies with whole grain diets on metabolic risk factors and weight regulation. The objective of this study was to explore the mechanism for a reduced post-prandial insulin demand with rye products. METHODS: 12 healthy subjects were given flour based rye products made from endosperm, whole grain or bran, produced with different methods (baking, simulated sour-dough baking and boiling) as breakfasts in random order in a cross-over design. White wheat bread (WWB) was used as a reference. Blood glucose, serum insulin, plasma ghrelin and subjective satiety were measured during 180 minutes. To evaluate the course of post-meal glycaemia, a measure of the glycaemic profile (GP) was introduced defined as the duration for the incremental post-prandial blood glucose response divided with the blood glucose incremental peak (min/mM). RESULTS: The study shows that whole grain rye breads and endosperm rye products induced significantly (p < 0.05) lower insulinaemic indices (II's) than WWB. Rye bran bread (RBB) produced significantly higher II compared with all the other rye products. Furthermore, the acute insulin response showed better correlations with the GP than with the GI of the products. The endosperm rye bread and the whole grain rye bread with lactic acid induced a significantly higher GP than RBB, WWB, white wheat- and whole grain rye porridge, respectively. A low insulin incremental peak was associated with less severe late post-prandial hypoglycaemia (r = 0.38, p < 0.001), and hypoglycaemia was negatively correlated to subjective satiety at 180 min (r = -0.28, p < 0.05). A low insulin incremental peak was also associated with a milder recovery of plasma ghrelin in the late post-prandial phase (180 min, r = 0.34, p < 0.01). CONCLUSION: Our study shows that endosperm and whole grain rye products induce low acute insulinaemic responses and improved glycaemic profiles. The results also suggest that the rye products possess beneficial appetite regulating properties. Further studies are needed to identify the unknown property or bioactive component(s) responsible for these beneficial metabolic features of rye.

Difficulties in Translating Appetite Sensations Effect of Turmeric-Based Beverage When Given Prior to Isoenergetic Medium- or High-Fat Meals in Healthy Subjects.

The established effect of turmeric and its curcuminoids on appetite sensations was previously shown to be mediated by gut hormones release. In in vitro and preclinical studies, curcumin was shown to induce GLP-1 secretion and improve postprandial glycemia. In humans, consumption of 220 mL turmeric-based beverage (TUR, containing 185 mg gallic acid equivalents (GAE)) prior to white wheat bread (WWB, 50 g available carbohydrate) reduced early postprandial glucose levels and induced peptide tyrosine⁻tyrosine (PYY) release, as well as lowered 'desire to eat' and 'prospective consumption' in a postprandial setting, compared to control. In the present study, 12 healthy participants (5 men, 7 women) were admitted. An identical beverage was given and consumed prior to isoenergetic (423 kcal) medium-fat (MF) or high-fat (HF) meals. Appetite sensations including perceived 'hunger', 'desire to eat', 'satiety', 'fullness', 'prospective consumption', and 'thirst' were measured using visual analogue scales. MF induced 18% (p = 0.039) higher 'satiety' compared to HF. TUR consumption prior to either MF or HF did not modulate the perceived appetite sensations. Whether macronutrient-induced appetite sensations override the actual turmeric effects warrants further investigation.

Postprandial Responses of Serum Bile Acids in Healthy Humans after Ingestion of Turmeric before Medium/High-Fat Breakfasts.

SCOPE: Bile acids (BAs) are known to regulate a number of metabolic activities in the body. However, very little is known about how BAs are affected by diet. This study aims to investigate whether a single dose of turmeric-based beverage (TUR) before ingestion of medium- (MF) or high-fat (HF) breakfasts would improve the BA profile in healthy subjects. METHODS AND RESULTS: Twelve healthy subjects are assigned to a randomized crossover single-blind study. The subjects receive isocaloric MF or HF breakfasts after a drink containing flavored water with or without an extract of turmeric with at least 1-week wash-out period between the treatments. Postprandial BAs are measured using protein precipitation followed by ultra-high-performance liquid chromatography-mass spectrometry analysis. The concentration of BAs is generally higher after HF than MF breakfasts. Ingestion of TUR before MF breakfast increases the serum concentrations of free and conjugated forms of cholic (CA) and ursodeoxycholic acids (UDCA), as well as the concentrations of chenodeoxycholic acid (CDCA) and its taurine-conjugated forms. However, the concentration of conjugated forms of deoxycholic acid (DCA) decreases when TUR is taken before HF breakfast. CONCLUSION: TUR ingestion before MF and HF breakfasts improve BA profiles and may therefore have potential health-promoting effects on BA metabolism.

Including indigestible carbohydrates in the evening meal of healthy subjects improves glucose tolerance, lowers inflammatory markers, and increases satiety after a subsequent standardized breakfast.

Low-glycemic index (GI) foods and foods rich in whole grain are associated with reduced risk of type 2 diabetes and cardiovascular disease. We studied the effect of cereal-based bread evening meals (50 g available starch), varying in GI and content of indigestible carbohydrates, on glucose tolerance and related variables after a subsequent standardized breakfast in healthy subjects (n = 15). At breakfast, blood was sampled for 3 h for analysis of blood glucose, serum insulin, serum FFA, serum triacylglycerides, plasma glucagon, plasma gastric-inhibitory peptide, plasma glucagon-like peptide-1 (GLP-1), serum interleukin (IL)-6, serum IL-8, and plasma adiponectin. Satiety was subjectively rated after breakfast and the gastric emptying rate (GER) was determined using paracetamol as a marker. Breath hydrogen was measured as an indicator of colonic fermentation. Evening meals with barley kernel based bread (ordinary, high-amylose- or beta-glucan-rich genotypes) or an evening meal with white wheat flour bread (WWB) enriched with a mixture of barley fiber and resistant starch improved glucose tolerance at the subsequent breakfast compared with unsupplemented WWB (P < 0.05). At breakfast, the glucose response was inversely correlated with colonic fermentation (r = -0.25; P < 0.05) and GLP-1 (r = -0.26; P < 0.05) and positively correlated with FFA (r = 0.37; P < 0.001). IL-6 was lower (P < 0.01) and adiponectin was higher (P < 0.05) at breakfast following an evening meal with barley-kernel bread compared with WWB. Breath hydrogen correlated positively with satiety (r = 0.27; P < 0.01) and inversely with GER (r = -0.23; P < 0.05). In conclusion, the composition of indigestible carbohydrates of the evening meal may affect glycemic excursions and related metabolic risk variables at breakfast through a mechanism involving colonic fermentation. The results provide evidence for a link between gut microbial metabolism and key factors associated with insulin resistance.

Black pepper-based beverage induced appetite-suppressing effects without altering postprandial glycaemia, gut and thyroid hormones or gastrointestinal well-being: a randomized crossover study in healthy subjects.

Pleiotropic effects of spices on health, particularly on glucose metabolism and energy regulation, deserve further clinical investigation into their efficacy. The aim of the current study was to evaluate whether consumption of a black pepper-based beverage (BPB) preload containing 20 mg gallic acid equivalent (GAE) would exert any effect on postprandial glycaemia, appetite sensations, gut hormones, thyroid function, and gastrointestinal well-being after a white wheat bread (WWB) challenge meal containing 50 g available carbohydrates (CHO) compared to a control beverage. Sixteen healthy subjects (10 men; 6 women; 26 ± 0.9 years; BMI 22.93 ± 0.53 kg m-2) completed a randomized, crossover intervention study. The BPB's bioactive compounds were characterized using ultra high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer with an electrospray ionization source (UHPLC-DAD-ESI-QTOF-MS). Nine compounds tentatively identified in BPB include: dihydroxybenzoic acid hexoside-pentoside, decaffeoyl-acteoside, cynaroside A, apigenin 6,8-di-C-hexoside, luteolin 6-C-hexoside-8-C-rhamnoside, apigenin 8-C-hexoside-C-deoxyhexoside, kaempferol 3-rhamnoside-4'-xyloside, apigenin 7-neohesperidoside, and apigenin-8-C-arabinopyranoside-2''-rhamnoside. Blood glucose and serum insulin responses, insulin sensitivity and ß-cell function were not affected during the acute intervention with BPB. Neither were effects on gastrointestinal well-being observed after BPB. However, BPB modulated overall acute appetite by lowering 'hunger', 'desire to eat', and 'prospective consumption', and increasing 'satiety' and 'fullness'. In contrast, there were no changes in gut (peptide tyrosine-tyrosine [PYY] and glucagon-like peptide-1 [GLP-1]) and thyroid (triiodothyronine [T3] and thyroxine [T4]) hormones after BPB compared to the control beverage. In conclusion, inclusion of BPB prior to the WWB challenge meal might be beneficial for appetite modulation, but we did not find supporting evidence in glycaemia, gut and thyroid hormones. Further studies are needed to elucidate the mechanisms of appetite-reducing pungent spices, such as black pepper.

On the Importance of Processing Conditions for the Nutritional Characteristics of Homogenized Composite Meals Intended for Infants.

The nutritional quality of infant food is an important consideration in the effort to prevent a further increase in the rate of childhood obesity. We hypothesized that the canning of composite infant meals would lead to elevated contents of carboxymethyl-lysine (CML) and favor high glycemic and insulinemic responses compared with milder heat treatment conditions. We have compared composite infant pasta Bolognese meals that were either conventionally canned (CANPBol), or prepared by microwave cooking (MWPBol). A meal where the pasta and Bolognese sauce were separate during microwave cooking (MWP_CANBol) was also included. The infant meals were tested at breakfast in healthy adults using white wheat bread (WWB) as reference. A standardized lunch meal was served at 240 min and blood was collected from fasting to 360 min after breakfast. The 2-h glucose response (iAUC) was lower following the test meals than with WWB. The insulin response was lower after the MWP_CANBol (-47%, p = 0.0000) but markedly higher after CANPBol (+40%, p = 0.0019), compared with WWB. A combined measure of the glucose and insulin responses (ISIcomposite) revealed that MWP_CANBol resulted in 94% better insulin sensitivity than CANPBol. Additionally, the separate processing of the meal components in MWP_CANBol resulted in 39% lower CML levels than the CANPBol. It was therefore concluded that intake of commercially canned composite infant meals leads to reduced postprandial insulin sensitivity and increased exposure to oxidative stress promoting agents.

An improved course of glycaemia after a bread based breakfast is associated with beneficial effects on acute and semi-acute markers of appetite.

The prevalence of type 2 diabetes mellitus is rapidly increasing all over the world and a diet promoting reduced glycaemic excursions in the postprandial phase may help to prevent the disease. In the present study guar gum (GG) and whole grain rye flour or high amylose maize starch (HAM) was combined to design bread products giving low and sustained glycaemia. A meal study was performed with young, healthy subjects and in addition to glucose and insulin, also subjective appetite ratings and biomarkers of appetite, voluntary energy intake at a second meal and markers of fermentation were studied. The combination of GG and rye was superior with improvements in subjective appetite whereas both test products lead to improvements in biomarkers of appetite compared to the white wheat bread reference. The inclusion of GG, rye and/or HAM in bread products show great potential in lowering risk factors associated with insulin resistance and improving acute and semi-acute appetite.

Characterization of antioxidant polyphenols from Myrciaria jaboticaba peel and their effects on glucose metabolism and antioxidant status: A pilot clinical study.

Brazilian berries, such as Myrciaria jaboticaba (jaboticaba), are good sources of polyphenols with a recognized function in oxidative stress attenuation proved in non-clinical studies. In the present study, the polyphenols profile and their contribution to the antioxidant capacity of the jaboticaba peel were analyzed using high-performance liquid chromatography (HPLC) with photodiode array (DAD), electrochemical (ECD), charged aerosol (CAD), and mass spectrometry (MS) detections. Anthocyanins, ellagitannins and gallotannins, ellagic acid and derivatives, and flavonols were found in jaboticaba. Anthocyanins were the phenolics found in higher concentrations. However, ellagitannins were the main contributors to the total antioxidant capacity. Moreover, the effect of jaboticaba peel intake on antioxidant and glucose parameters in a single-blind placebo-controlled crossover study was investigated. The serum antioxidant capacity was significantly higher when the subjects had consumed the test meal containing jaboticaba. Serum insulin decreased subsequent to the second meal at 4h after jaboticaba peel consumption.