Postprandial glucose-lowering effect of premeal consumption of protein-enriched, dietary fiber-fortified bar in individuals with type 2 diabetes mellitus or normal glucose tolerance

Sequence of Eating at Japanese-Style Set Meals Improves Postprandial Glycemic Elevation in Healthy People

BACKGROUND

The meal sequencing of macronutrients has been shown to ameliorate postprandial glucose excursion, but its effects in daily meals has not been investigated. We examined the impact on the glucose response to meal sequencing in healthy Japanese adults using continuous glucose monitoring (CGM) during a typical lunch meal.

METHODS

The test meal was a Japanese set meal or a beef and rice bowl, the contents of which were categorized as "rice" or "non-rice". In the meal experiments, the subjects ingested the two categories of food in one of three orders: non-rice before rice, non-rice and rice together, and non-rice after rice. In the beef and rice bowl experiments, the subjects ingested either non-rice 15 min before rice or the two foods together.

RESULTS

The postprandial glucose level was measured over a 4 h period and the mean level of postprandial glucose was significantly lower than that when eating rice before non-rice or both together. Consuming non-rice before rice significantly reduced postprandial glycemic excursions in healthy adults in both experiments.

CONCLUSIONS

Meal-sequencing by "eat carbs last" is a feasible dietary strategy for the better prevention and management of diabetes.

Postprandial Glucose Response in Type 2 Diabetes Mellitus Patients and Possible Antioxidant Properties of a Plant-Based Snack Bar

Daily, more and more people consume snack bars that may have an impact on blood glucose levels. The aim of the present study was to compare the acute effects of a common snack and a plant-based snack bar (PB) that was developed at the University of Thessaly as a functional diabetic snack on blood glucose and insulin in patients with type 2 diabetes mellitus (T2DM). Adults with T2DM (n = 10) treated with oral medications were studied in a randomized, crossover clinical trial. On each trial day, postprandial glucose and insulin levels were measured at 30, 60, 90, and 120 min, and a morning snack containing 25 g of carbohydrate was consumed. The procedure was carried out on 2 days, with one of the test meals being consumed on each day. Consumption of a PB snack bar resulted in a smaller and steeper increase in postprandial glucose and insulin levels compared with the usual snack, and there were significant differences 60 and 90 min after consumption of the two tested snacks. The PB snack bar is rich in protein, fiber, vitamins, and minerals and can therefore be suggested as a nutritious and convenient snack for patients with T2DM. In addition, the extract of the snack bar was tested for its bioactivity in human cell cultures.

Postprandial Glucose and Insulin Response to Meal Sequence Among Healthy UAE Adults: A Randomized Controlled Crossover Trial

Background

Dietary patterns that lower postprandial glycemia have been effective in preventing type 2 diabetes. Consuming macronutrients in a specific sequence within a meal has been considered as a novel strategy to reduce post-meal glucose spikes. Therefore, this study aimed to investigate the effect of meal sequence on postprandial glucose and insulin response among healthy adults in the United Arab Emirates.

Methods

Eighteen healthy adults participated in a cross-over randomized controlled trial. Two isocaloric meals were consumed separately in a different order: a standard mixed meal (SMM) vs vegetables and protein first followed by carbohydrates (VPF) meal. The postprandial glucose and insulin levels were determined at Fasting, 30, 60, and 120 min. Visual Analog Scale (VAS) rating was used to assess hunger at similar frequencies.

Results

The mean glucose and insulin levels significantly reduced (p = 0.001) following VPF meal compared to SMM at 30 min. The incremental area under the curve (iAUC0-120) for glucose following the VPF meal sequence was 40.9% lower (p = 0.03) compared with the SMM (572.83; 95% CI 157.3 to 988.2) vs (968.5; 95% CI 692.4 to 1244.8 mg/dL). Furthermore, the iAUC0-120 for insulin following the VPF meal sequence was 31.7% lower than the SMM meal sequence. (2184; 95% CI 1638.30 to 2729) vs (3196.94; 95% CI 2328.19 to 4065.69) mIU/mL × 120 min, P = 0.023). The feeling of fullness measured by the hunger scale showed that the feeling of fullness was higher after 60 and 120 minutes (p = 0.05, p = 0.04) with the VPF meal sequence compared to the SMM sequence. Although, there is no significant difference in the Area under the curve (AUC) for hunger rating between the two meals.

Conclusion

The VPF meal sequence could significantly reduce postprandial glucose and insulin levels and sustain fullness after a meal. Meal sequencing could be an effective dietary strategy for improving the postprandial glucose and insulin response in healthy adults.

The effect of a pre-meal snack and/or postprandial exercise on breakfast glycemic excursion in adults with cystic fibrosis: A pilot study

BACKGROUND & AIMS

Cystic fibrosis (CF)-related diabetes (CFRD), a common comorbidity in CF, is often preceded and characterized with elevated postprandial glycemic (PPG) excursions. In the general population, the consumption of a pre-meal protein snack and/or physical activity (PA) hinder the elevation of PPG levels. Our objective is to evaluate the effect of a pre-meal snack and/or post-meal PA on PPG excursions in CF.

METHODS

This is a double-blinded randomized controlled crossover interventional study in 14 adults with CF, with 4 interventions: placebo pre-meal snack + no PA (control: CTL), pre-meal soy snack + no PA (SK), placebo pre-meal snack + PA (PA), and pre-meal soy snack + PA (SK + PA). The pre-meal soy snack or placebo beverage (vanilla flavoured water) is served at 8 AM, followed by a standardized breakfast at 9 AM and, postprandially, 5 repeated bouts of 3-min walk every 30 min or sedentary activity. Blood glucose and insulin were measured every 15-30 min during the interventions.

RESULTS

Plasma glucose (PG) was higher 30 min after snack consumption compared to placebo beverage. One-hour post-breakfast, PG levels were lower during both PA interventions than with sedentary behavior. However, the overall 3 h post-breakfast glucose area under the curve (AUC) was similar between interventions. Post-breakfast 3 h insulin AUC was significantly lower during the SK + PA intervention compared to the sedentary behavior interventions.

CONCLUSION

Repeated short bouts of post-meal physical activity may positively impact PPG control in adults with CF, with or without the addition of a pre-meal soy snack. A pre-meal snack alone does not improve PPG.

Inhibitory activities and rules of plant gallotannins with different numbers of galloyl moieties on sucrase, maltase and α-amylase in vitro and in vivo

BACKGROUND

α-Glucosidase inhibitors could effectively reduce postprandial blood glucose (PBG) levels and control the occurrence of complications of diabetes. Gallotannins (GTs) in plants have attracted much attention due to their significant α-glucosidase inhibitory activities in vitro. However, there is still a lack of systematic comparative studies to further elucidate inhibitory activities in vivo and in vitro of these compounds against α-glucosidase, especially for mammalian sucrase and maltase, and analyze their structure-activity relationship.

PURPOSE

Determine the in vitro and in vivo inhibitory activities of five GTs with different number of galloyl moieties (GMs) on sucrase, maltase and α-amylase, and elucidate the relationship between α-glucosidase inhibitory activities and the number and connection mode of GMs.

METHODS

Molecular docking and dynamics were used to study the binding mode and binding ability of five GTs against sucrase, maltase and α-amylase. Then, the inhibitory activities and inhibitory mechanisms of these compounds on sucrase, maltase and α-amylase in vitro were studied using inhibitory assay and enzyme inhibition kinetics. Further, the hypoglycemic effects in vivo of these compounds were demonstrated by three polysaccharides tolerance experiments on diabetes model mice.

RESULTS

The results of molecular docking showed that these compounds could bind to enzymes through hydrogen bonds, hydrophobic interactions, etc. In addition, the α-glucosidase inhibition comparative studies in vitro and in vivo demonstrated that the inhibitory activities of these compounds on all three sucrase, maltase and α-amylase were ranked as TA ≈ PGG > TeGG > TGG > 1GG, and their inhibitory activities increases with the increase in the number of GMs. Moreover, the hypoglycemic effects of 1,2,3,4,6-pentagalloylglucose (PGG) and tannic acid (TA) in vitro and in vivo were also confirmed to be equivalent to or even stronger than that of acarbose.

CONCLUSION

α-Glucosidase inhibitory activities in vitro and in vivo of GTs were positively correlated with the number of GTs, and the more the number, the stronger the activity. However, PGG with five GTs and TA with ten GTs showed almost identical α-glucosidase inhibitory activities, possibly due to the reduced binding force with the enzyme caused by spatial hindrance.

Development of a Functional Acceptable Diabetic and Plant-Based Snack Bar Using Mushroom (Coprinus comatus) Powder

Consumers' growing concern about health and well-being has led to increased interest in functional foods. This research aims to evaluate the physicochemical and antioxidant properties of a functional plant-based (PB) snack bar enriched with Coprinus comatus powder. The snack bar formulations exhibited a wide range of flavor and textural characteristics. Two PB snack bars and four commercial bars were evaluated by a consumer panel of healthy volunteers (n = 20). The PB snack bar scored 'like extremely' on the 9-point hedonic scale. External preference mapping determined that sweetness, flavors, cohesiveness, gumminess, and adhesion had the greatest influence on consumer acceptability. Water content, ash, protein, fat, carbohydrate, reducing sugar, resistant starch, and dietary fiber were measured. Nutritional content was enhanced (omega 3, fiber and protein), and samples were shelf life stable (aw < 0.29; moisture content < 10%). In addition, the PB snack bar underwent simulated digestion according to the INFOGEST protocol, and from the comparative evaluation, the PB snack can be seen to control the post-prandial glycemic responses, as observed by the different degree of reducing sugars released via the matrix. The PB snack bar can be further functionally enhanced by the addition of their unique ingredients such as Coprinus comatus. Coprinus comatus powder is claimed to benefit glycemic control in diabetes and has attracted growing interest in terms of its potential use in natural products with possible health benefits.

A Pilot Study to Assess Glucose, Insulin, and Incretin Responses Following Novel High Resistant Starch Rice Ingestion in Healthy Men

INTRODUCTION

A newly developed resistant starch (RS) rice line with double mutation of starch synthase IIIa and branching enzyme IIb (ss3a/be2b) exhibits a tenfold greater percentage RS value than the wild-type rice line. Currently, the effects of cooked rice with such high RS content on secretion and action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are unclear. Therefore, we conducted a pilot study to assess postprandial responses of GLP-1 and GIP along with glucose and insulin and also gastric emptying after ingestion of the high-RS cooked rice with ss3a/be2b in healthy subjects.

METHODS

In a non-randomized crossover design, five healthy men ingested two test foods, control (low-RS) and high-RS cooked rice, with at least 1-week washout period between testing days. Plasma glucose, serum insulin, plasma total GLP-1, plasma total GIP, and also gastric emptying rate were measured after ingestion of each test food, and the incremental area under the curves (iAUC) was calculated for each biochemical parameter using the values from 0 to 180 min after ingestion.

RESULTS

The high-RS cooked rice ingestion tended to reduce iAUC-glucose (p = 0.06) and significantly reduced iAUC-insulin (p < 0.01) and iAUC-GLP-1 (p < 0.05) but not iAUC-GIP (p = 0.21) relative to control cooked rice ingestion. In addition, the high-RS cooked rice ingestion did not affect gastric emptying.

CONCLUSIONS

The present results indicate that the suppressive effects of the high-RS cooked rice ingestion on postprandial responses of glucose and insulin may be provided through attenuation in GLP-1 secretion along with its low digestibility into glucose. We suggest that the high-RS rice with ss3a/be2b may serve as a better carbohydrate source and also as a novel functional food for dietary interventions to improve postprandial hyperglycemia and hyperinsulinemia without both enhancing GLP-1 secretion and affecting gastric emptying in patients with diabetes.

Efficacy of a meal sequence in patients with type 2 diabetes: a systematic review and meta-analysis

INTRODUCTION

This systematic review investigated the efficacy of a meal sequence, the carbohydrate-later meal pattern (CL), on type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov until April 2020 to perform meta-analyses using random-effects models. Primary outcomes were hemoglobin A1c (HbA1c) and quality of life. Secondary outcomes were plasma concentrations of glucose, insulin and incretin 120 min after a meal, and any adverse outcomes. The revised Cochrane risk-of-bias tool and Grading of Recommendations, Assessment, Development, and Evaluation approach were used to assess the quality of individual studies and the body of evidence, respectively. The present study was registered in the UMIN Clinical Trials Registry.

RESULTS

We included 230 participants in eight trials, including both trials that examined long-term changes (more than 2 months and less than 2 years) and short-term changes (in 2-hour postprandial values). CL resulted in a slight to no difference in HbA1c (mean difference (MD), -0.21% in the intervention group; 95% CI -0.44% to+0.03%), plasma glucose (MD,+4.94 mg/dL; 95% CI -8.34 mg/dL to +18.22 mg/dL), plasma insulin (MD, -3.63 μIU/mL; 95% CI -11.88 μIU/mL to +4.61 μIU/mL), plasma GLP-1 (MD, +0.43 pmol/L; 95% CI -0.69 pmol/L to +1.56 pmol/L), and plasma GIP (MD, -2.02 pmol/L; 95% CI -12.34 pmol/L to +8.31 pmol/L). All of these outcomes were of low-certainty evidence or very low-certainty evidence. None of the trials evaluated quality of life or adverse events.

CONCLUSIONS

There was no evidence for the potential efficacy of recommending CL beyond standard dietary advice on T2DM.

TRIAL REGISTRATION NUMBER

UMIN000039979.

Nutritional management of type 2 diabetes in subjects with obesity: an international guideline for clinical practice

Type 2 diabetes mellitus (T2DM) and obesity represent a global public health problem. Current nutritional recommendations focused on weight loss and overall dietary quality. However, there is no consensus on the optimal macronutrient composition of the diet, particularly for the long-term management of T2DM in subjects with obesity. An international panel of experts reviewed and critically appraised the updated literature published on the topic. This review primarily examines the evidence for areas of consensus and uncertainty about nutritional therapy in patients with T2DM and obesity. The aim of this article is to provide nutritional advice to manage these patients in clinical practice.

Whey protein preloading can alleviate stress adaptation disorder and improve hyperglycemia in women with gestational diabetes mellitus

AIMS

To investigate the change of stress hormones, oxidative stress and insulin resistance (IR) in women with gestational diabetes mellitus (GDM) after supplement whey protein, in an attempt to gain insights into the prevention and treatment of GDM.

MATERIALS AND METHODS

60 GDM women were recruited in this study, and 30 women received a preload drink containing 20 g whey protein as group GDM-W, and the other 30 women received control flavoring drink as group GDM, and the trial lasted for 14 days. Plasma epinephrine (E), noradrenaline (NE), and cortisol were detected; we also determined levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH). Homeostasis model assessment of insulin resistance (HOMA-IR) was used to assess IR.

RESULTS

In the GDM-W group, postprandial blood glucose was decreased significantly on 3, 5, 7, and 14 days (all p < .05), plasma 2 h insulin was increased by 7.2, 8.6, and 20.5% on days 5, 7, and 14 (p < .05, .05, .01). HOMA-IR was decreased significantly on day 14 (p < .05). MDA was decreased by 20.7% on day 14 (p < .01), and anti-oxidative enzymes' SOD was decreased by 13.4% on day 14 (p < .05) and GSH was decreased by 16.7 and 29.1% on days 7 and 14 (both p < .05). Stress hormones E and cortisol were decreased by 10.8 and 19.8%, respectively, on day 14 (p < .05). There was no significant difference in NE between the two groups within 14 days.

CONCLUSIONS

Whey protein supplementation may improve hyperglycemia by alleviating stress disorder and oxidative stress injury in GDM women. This trial was registered at chictr.org.cn/as ChiCTR1800020413.

Dietary Aspects to Incorporate in the Creation of a Mobile Image-Based Dietary Assessment Tool to Manage and Improve Diabetes

Diabetes is the seventh leading cause of death in United States. Dietary intake and behaviors are essential components of diabetes management. Growing evidence suggests dietary components beyond carbohydrates may critically impact glycemic control. Assessment tools on mobile platforms have the ability to capture multiple aspects of dietary behavior in real-time throughout the day to inform and improve diabetes management and insulin dosing. The objective of this narrative review was to summarize evidence related to dietary behaviors and composition to inform a mobile image-based dietary assessment tool for managing glycemic control of both diabetes types (type 1 and type 2 diabetes). This review investigated the following topics amongst those with diabetes: (1) the role of time of eating occasion on indicators of glycemic control; and (2) the role of macronutrient composition of meals on indicators of glycemic control. A search for articles published after 2000 was completed in PubMed with the following sets of keywords “diabetes/diabetes management/diabetes prevention/diabetes risk”, “dietary behavior/eating patterns/temporal/meal timing/meal frequency”, and “macronutrient composition/glycemic index”. Results showed eating behaviors and meal macronutrient composition may affect glycemic control. Specifically, breakfast skipping, late eating and frequent meal consumption might be associated with poor glycemic control while macronutrient composition and order of the meal could also affect glycemic control. These factors should be considered in designing a dietary assessment tool, which may optimize diabetes management to reduce the burden of this disease.

TLC-MS Bioautography-Based Identification of Free-Radical Scavenging, α-Amylase, and α-Glucosidase Inhibitor Compounds of Antidiabetic Tablet BGR-34

BGR-34 is a polyherbal formulation frequently used to combat diabetes around the globe especially in Asian countries. It provides an attractive treatment option to prediabetics, diabetics, and in metabolic disorders by controlling the altered blood glucose level. The lack of phytopharmacological studies on BGR-34 prompted as to reveal the compounds responsible for the antidiabetic and free-radical scavenging activity of BGR-34. An attempt was made to assess in vitro α-amylase and α-glucosidase enzyme inhibition of BGR-34 along with its free-radical scavenging potential via DPPH scavenging activity. Further, HPTLC profiling and quantitative analysis of berberine and palmatine in BGR-34 were carried out. Thereafter, the TLC-bioautographic-MS analysis was performed to identify the compounds responsible for antidiabetic and antioxidant activities in BGR-34. The results had shown a significant and dose-dependent inhibition potential of BGR-34 against in vitro α-amylase and α-glucosidase enzymatic reactions along with significant inhibition in DPPH free-radical scavenging activity. The HPTLC profiling and quantitative validation studies showed the presence of berberine and palmatine 44.926 ± 0.2907 and 10.507 ± 0.154 μg/g, respectively. The TLC-MS bioautography revealed a total of four DPPH-active, two α-amylase-active, and nine α-glucosidase-active compounds in BGR-34. It was observed from the study that BGR-34 possesses verities of bioactive compounds, which are reasonable not only for its antidiabetic effect but also for its antioxidant activity.

Changes in the glucose and insulin responses according to high-protein snacks for diabetic patients

BACKGROUND/OBJECTIVES

This study aimed to develop healthy, appetizing high-protein snacks with enhanced isolated soy protein for diabetic patients and determine the blood glucose and insulin response after being consumed by these patients.

MATERIALS/METHODS

Thirty adult patients aged between 30 and 75 years, with a ≤ 10-year history of type 2 diabetes and hemoglobin A1c of < 7.5%, were enrolled in this study. They made 3 clinical visits at one-week intervals. The control group consumed 50 g carbohydrates (white bread), whereas the test groups consumed high-protein grain (HP_G) or high-protein chocolate (HP_C) after an 8-hrs fast. Blood (2 cm³) was drawn at 15, 30, 45, 60, 90, and 120 min before and after consumption to analyze the blood glucose and insulin concentrations.

RESULTS

Compared to the commercial snacks, the developed high-protein snacks had below-average calorie, carbohydrate, and fat content and a 2.5-fold higher protein content. In diabetic patients who consumed these snacks, the postprandial blood glucose increased between 15 min and 2 h after consumption, which was significantly slower than the time taken for the blood glucose to increase in the patients who consumed the control food product (P < 0.001). Insulin secretion was significantly lower at 45 min after consumption (P < 0.05), showing that the high-protein snacks did not increase the blood glucose levels rapidly. The incremental area under the curve (iAUC), which indicated the degree of blood sugar and insulin elevation after food intake, was higher in the control group than the groups given the 2 developed snacks (P < 0.001), and there was no significant difference in insulin secretion.

CONCLUSIONS

The results of the postprandial blood glucose and insulin response suggest that high-protein snacks are potential convenient sources of high-quality protein and serve as a healthier alternative for patients with type 2 diabetes, who may have limited snack product choices. Such snacks may also provide balanced nutrition to pre-diabetic and obese individuals.

Nutrient consumption-dependent association of a glucagon-like peptide-1 receptor gene polymorphism with insulin secretion

Since type 2 diabetes (DM) is a life-style related disease, life-style should be considered when association between genetic factors and DM are examined. However, most studies did not examine genetic associations in consideration with lifestyle. Glucagon-like peptide-1 (GLP-1) receptor (GLP1R) mediates the insulinotropic action of GLP-1 in β-cells. We here examined the association while taking into consideration of interactions between the gene polymorphism and various nutrient factors. Participants from the population-based Iwaki study of Japanese subjects held in 2014–2017 with information on nutritional intake evaluated by self-administered dietary history questionnaire, and GLP1R genotype (rs3765467: A/G), were included (n = 1,560). Although not significant, insulin secretion indices assessed by homeostasis model assessment of β-cell function (HOMA-β) in subjects with the GG genotype tended to be lower than in those with the AA+AG genotypes in most groups stratified into tertiles based on daily nutrient consumptions (high, middle, and low). Stratification also showed that the GG genotype was a significant risk for decreased insulin secretion (HOMA-β ≤ 30) even after adjustment for multiple factors (age, body mass index, alcohol consumption), but only in the highest tertiles of energy, protein and carbohydrate consumption in men [odds ratios (95% confidence interval) 3.95 (1.03–15.1), 15.83 (1.58–158.9), and 4.23 (1.10–11.2), respectively]. A polymorphism of the GLP1R gene was associated with decreased insulin secretion in a nutrient consumption-dependent manner in Japanese men, indicating an interaction between GLP1R and nutritional factors in the pathophysiology of DM.

A Narrative Review of the Anti-Hyperglycemic and Satiating Effects of Fish Protein Hydrolysates and Their Bioactive Peptides

Prevalence of type 2 diabetes and overweight/obesity are increasing globally. Food supplementation as a preventative option has become an attractive option in comparison to increased pharmacotherapy dependency. Hydrolysates of fish processing waste and by-products have become particularly interesting in a climate of increased food wastage awareness and are rapidly gaining traction in food research. This review summarizes the available research so far on the potential effect of these hydrolysates on diabetes and appetite suppression. Scopus and Web of Science are searched using eight keywords (fish, hydrolysate, peptides, satiating, insulinotropic, incretin, anti-obesity, DPP-4 [dipeptidylpeptidase-4/IV]) returning a total of 2549 results. Following exclusion criteria (repeated appearances, non-fish marine sources [e.g., macroalgae], and irrelevant bioactivities [e.g., immunomodulatory, anti-thrombotic]), 44 relevant publications are included in this review. Stimulation of hormone secretion, regulation of glucose uptake, anorexigenic potential, identified mechanisms of action, and research conducted on the most potent bioactive peptides identified within these hydrolysates are all specifically addressed. Results of this review conclude that despite wide methodological variation between studies, there is significant potential for the application of fish protein hydrolysates in the management of bodyweight and hyperglycemia.

A Review of Recent Findings on Meal Sequence: An Attractive Dietary Approach to Prevention and Management of Type 2 Diabetes

While adjustment of total energy and nutritional balance is critically important, meal sequence, a relatively simple method of correcting postprandial hyperglycemia, is becoming established as a practical dietary approach for prevention and management of diabetes and obesity. Meal sequence, i.e., consumption of protein and/or fat before carbohydrate, promotes secretion of glucagon-like peptide-1 (GLP-1) from the gut and ameliorates secretions of insulin and glucagon and delays gastric emptying, thereby improving postprandial glucose excursion. GLP-1 is known to suppress appetite by acting on the hypothalamus via the afferent vagus nerve. Thus, enhancement of GLP-1 secretion by meal sequence is expected to reduce body weight. Importantly, consumption of a diet rich in saturated fatty acids such as meat dishes before carbohydrate increases secretions of not only GLP-1 but also glucose-dependent insulinotropic polypeptide (GIP), which promotes energy storage in adipose tissue and may lead to weight gain in the long term. Dietary fiber intake before carbohydrate intake significantly reduces postprandial glucose elevation and may have a weight loss effect, but this dietary strategy does not enhance the secretion of GLP-1. Thus, it is suggested that their combination may have additive effects on postprandial glucose excursion and body weight. Indeed, results of some clinical research supports the idea that ingesting dietary fiber together with meal sequence of protein and/or fat before carbohydrate benefits metabolic conditions of individuals with diabetes and obesity.

Premeal Consumption of a Protein-Enriched, Dietary Fiber-Fortified Bar Decreases Total Energy Intake in Healthy Individuals

BACKGROUND

A premeal load of protein can increase satiety and reduce energy intake. Dietary fiber also conveys metabolic benefits by modulating energy intake. We made a protein-enriched, dietary fiber-fortified bar (PFB) and aimed to investigate its effects on food intake and gut hormone secretion in healthy individuals.

METHODS

Twenty subjects with normal glucose tolerance were enrolled. On three separate visits, the subjects received, in a randomized order, one of the following: a PFB containing 73 kcal with 10.7 g of protein and 12.7 g of dietary fiber; a usual bar (UB) containing the same calories as the PFB but only 0.9 g of protein and no dietary fiber; or water (control). After 15 minutes, the subjects had ad libitum intake of a test meal. Food consumption, appetite, and plasma gut hormone levels were measured.

RESULTS

Total energy intake, including the bar and the test meal, was significantly reduced with the PFB preload compared to the water (904.4±534.9 kcal vs. 1,075.0±508.0 kcal, P=0.016). With the UB preload, only the intake of the test meal was reduced (P=0.044) but not the total energy intake (P=0.471) than the water. Fullness was also significantly increased after the PFB. In addition, postprandial glucose levels decreased and glucagon-like peptide-1 levels increased with the PFB compared with both the UB and water.

CONCLUSION

In healthy individuals, a premeal supplementation of PFB reduced total energy intake and decreased postprandial glucose excursion. This finding necessitates long-term studies regarding clinical use in obesity.

A ketone monoester drink reduces the glycemic response to an oral glucose challenge in individuals with obesity: a randomized trial

BACKGROUND

Exogenous ketones make it possible to reach a state of ketosis that may improve metabolic control in humans.

OBJECTIVES

The main objective of this study was to determine whether the ingestion of a ketone monoester (KE) drink before a 2-h oral-glucose-tolerance test (OGTT) would lower blood glucose concentrations. Secondary objectives were to determine the impact of KE on nonesterified fatty acid (NEFA) concentration and glucoregulatory hormones.

METHODS

We conducted a randomized controlled crossover experiment in 15 individuals with obesity (mean ± SD age: 47 ± 10 y; BMI: 34 ± 5 kg/m2). After an overnight fast, participants consumed a KE drink [(R)-3-hydroxybutyl (R)-3-hydroxybutyrate; 0.45 mL/kg body weight] or taste-matched control drink 30 min before completing a 75-g OGTT. Participants and study personnel performing laboratory analyses were blinded to each condition.

RESULTS

The KE increased d-β-hydroxybutyrate to a maximum of ∼3.4 mM (P < 0.001) during the OGTT. Compared with the control drink, KE reduced glucose (-11%, P = 0.002), NEFA (-21%, P = 0.009), and glucagon-like peptide 1 (-31%, P = 0.001) areas under the curve (AUCs), whereas glucagon AUC increased (+11%, P = 0.030). No differences in triglyceride, C-peptide, and insulin AUCs were observed after the KE drink. Mean arterial blood pressure decreased and heart rate increased after the KE drink (both P < 0.01).

CONCLUSIONS

A KE drink consumed before an OGTT lowered glucose and NEFA AUCs with no increase in circulating insulin. Our results suggest that a single drink of KE may acutely improve metabolic control in individuals with obesity. Future research is warranted to examine whether KE could be used safely to have longer-term effects on metabolic control. This trial was registered at clinicaltrials.gov as NCT03461068.

Dietary recommendations for type 2 diabetes patients: Lessons from recent clinical and basic research in Asia

Dishes containing dietary fibers are eaten first, and the protein and fat courses are then followed by the carbohydrate dishes.

Impact of Nutrient Type and Sequence on Glucose Tolerance: Physiological Insights and Therapeutic Implications

Pharmacological and dietary interventions targeting postprandial glycemia have proved effective in reducing the risk for type 2 diabetes and its cardiovascular complications. Besides meal composition and size, the timing of macronutrient consumption during a meal has been recently recognized as a key regulator of postprandial glycemia. Emerging evidence suggests that premeal consumption of non-carbohydrate macronutrients (i.e., protein and fat "preloads") can markedly reduce postprandial glycemia by delaying gastric emptying, enhancing glucose-stimulated insulin release, and decreasing insulin clearance. The same improvement in glucose tolerance is achievable by optimal timing of carbohydrate ingestion during a meal (i.e., carbohydrate-last meal patterns), which minimizes the risk of body weight gain when compared with nutrient preloads. The magnitude of the glucose-lowering effect of preload-based nutritional strategies is greater in type 2 diabetes than healthy subjects, being comparable and additive to current glucose-lowering drugs, and appears sustained over time. This dietary approach has also shown promising results in pathological conditions characterized by postprandial hyperglycemia in which available pharmacological options are limited or not cost-effective, such as type 1 diabetes, gestational diabetes, and impaired glucose tolerance. Therefore, preload-based nutritional strategies, either alone or in combination with pharmacological treatments, may offer a simple, effective, safe, and inexpensive tool for the prevention and management of postprandial hyperglycemia. Here, we survey these novel physiological insights and their therapeutic implications for patients with diabetes mellitus and altered glucose tolerance.