Acute Effect of Resistant Starch on Food Intake, Appetite and Satiety in Overweight/Obese Males

Impact of resistant starch: Absorption of dietary minerals, glycemic index and oxidative stress in healthy rats

BACKGROUND & AIMS

Resistant starch (RS) is a prebiotic fiber that has been scientifically shown to control the development of obesity. Prebiotic role of RS has also seen to be very important as it helps gut bacteria to regulate fermentation and fatty acid production. This study aimed to check the different levels of RS on glycemic index, oxidative stress and mineral absorption rate in healthy rat models. To evaluate these objectives, the trial was conducted for 40 days of follow up; 10 days were the adjustment period and the collection period over 30 days.

METHODS

Thirty-six healthy female Wistar rats were divided into 4 groups of (9 animals each) NC (Normal Control: without resistant starch), RS0.20 (resistant starch: 0.20 g/kg body weight), RS0.30 (resistant starch: 0.30 g/kg body weight), RS0.40 (resistant starch: 0.40 g/kg body weight). All the diets were isocaloric and isonitroginous.

RESULTS

The impact of different levels of RS on the dry-matter intake (DMI) presented statistically significant results (p ≤ 0.05): DMI was reduced in RS (0.02) fed rats as compared to NC rats in first 3 weeks; and after 4th and 5th weeks, there was a DMI reduction of 28% in RS (0.04) fed rats. Moreover, there was no significant increase in the nutrient intake in all RS diets. The dry-matter (DM) digestibility was statistically significantly (P ≤ 0·05), which increased in all rats fed with different level of RS. The weight loss showed statistically significant results: RS (0.04) exhibited 19 g reduction in weight as compared with NC rats. Significant increase was observed in total oxidant status (TOS), in all the RS fed rats when compared with NC rats. The levels of Mg, Ca, Fe and Zn were shown to be decrease in feces analysis, which proves their better absorbance in gut. Statistically significant increase was observed in antioxidant capacity, whereas significant decrease was observed in the total weight of the animals, showing the role of RS in controlling obesity.

CONCLUSIONS

Overall, significant results were found in all dosage level of RS but long term administration of the higher dosage level (RS0.40) may need to be studied for enhanced results. RS can help improve insulin sensitivity in overweight adults.

Effects of resistant starch on glycemic response, postprandial lipemia and appetite in subjects with type 2 diabetes

PURPOSE

Resistant starch (RS) content has exhibited beneficial effects on glycemic control; however, few studies have investigated the effects of this substance on postprandial responses and appetite in subjects with type 2 diabetes (T2D). Here, we aimed to examine the effects of RS from two sources on glycemic response (GR), postprandial lipemia, and appetite in subjects with T2D.

METHODS

In a randomized and crossover study, 17 subjects with T2D consumed native banana starch (NBS), high-amylose maize starch (HMS) or digestible maize starch (DMS) for 4 days. On day 5, a 6-h oral meal tolerance test (MTT) was performed to evaluate glycemic and insulinemic responses as well as postprandial lipemia. Besides, subjective appetite assessment was measured using a visual analogue scale.

RESULTS

NBS induced a reduction on fasting glycemia, glycemia peak and insulinemic response during MTT. However, no modifications on postprandial lipemia were observed after RS treatments. Both NBS and HMS reduced hunger and increased satiety.

CONCLUSION

NBS supplementation induced more beneficial effects on glycemic metabolism than HMS even when all interventions were matched for digestible starch content. RS intake did not modify postprandial lipemia, however, positively affected subjective appetite rates.

TRIAL REGISTRATION

This trial was retrospectively registered at www.anzctr.org.au (ACTRN12621001382864) on October 11, 2021.

Resistant starch improves cardiometabolic disease outcomes: A narrative review of randomized trials

Healthy dietary patterns with adequate fiber improve cardiometabolic (CM) outcomes and attenuate disease progression. Resistant starch (RS) is a fermentable fiber that affects CM outcomes; however, studies are heterogeneous and inconsistent. Thus, the purpose of this narrative review is to assess the impact of RS intake by type and amount on CM outcomes while considering subject characteristics and trial duration. Randomized crossover or parallel studies (n = 31) were selected and compared according to acute (1 day; n = 12), medium (>1-30 days; n = 8), or long (>30 days; n = 11) duration. Most acute trials in healthy adults showed improvements in postprandial glycemic outcomes irrespective of RS type or amount. However, a more pronounced reduction occurred when test meals did not match for available carbohydrate. Daily RS intake had a minimal effect on CM outcomes in medium duration trials, but insulin resistant adults had better glycemic control at 4 weeks. Several longer duration trials (8-12 weeks) showed favorable CM outcomes with daily RS intake in adults with type 2 diabetes (T2D), but not in those at risk for T2D. Furthermore, some studies reported improved lipids, inflammatory biomarkers, and heart rate. Future studies should consider matching for available carbohydrates between the RS and control groups to understand the gut microbiome's role. Furthermore, energy and fiber should be considered. Overall, the acute intake of RS improves glycemic outcomes, and consuming RS at for least 4 and up to 8 to 12 weeks in adults with prediabetes and T2D, respectively, appears to improve CM outcomes.

A comparison of the effects of resistant starch types on glycemic response in individuals with type 2 diabetes or prediabetes: A systematic review and meta-analysis

Background

Type 2 diabetes (T2D) diagnoses are predicted to reach 643 million by 2030, increasing incidences of cardiovascular disease and other comorbidities. Rapidly digestible starch elevates postprandial glycemia and impinges glycemic homeostasis, elevating the risk of developing T2D. Starch can escape digestion by endogenous enzymes in the small intestine when protected by intact plant cell walls (resistant starch type 1), when there is a high concentration of amylose (resistant starch type 2) and when the molecule undergoes retrogradation (resistant starch type 3) or chemical modification (resistant starch type 4). Dietary interventions using resistant starch may improve glucose metabolism and insulin sensitivity. However, few studies have explored the differential effects of resistant starch type. This systematic review and meta-analysis aims to compare the effects of the resistant starch from intact plant cell structures (resistant starch type 1) and resistant starch from modified starch molecules (resistant starch types 2-5) on fasting and postprandial glycemia in subjects with T2D and prediabetes.

Methods

Databases (PubMed, SCOPUS, Ovid MEDLINE, Cochrane, and Web of Science) were systematically searched for randomized controlled trials. Standard mean difference (SMD) with 95% confidence intervals (CI) were determined using random-effects models. Sub-group analyses were conducted between subjects with T2D versus prediabetes and types of resistant starch.

Results

The search identified 36 randomized controlled trials (n = 982), 31 of which could be included in the meta-analysis. Resistant starch type 1 and type 2 lowered acute postprandial blood glucose [SMD (95% CI) = -0.54 (-1.0, -0.07)] and [-0.96 (-1.61, -0.31)]. Resistant starch type 2 improved acute postprandial insulin response [-0.71 (-1.31, -0.11)]. In chronic studies, resistant starch type 1 and 2 lowered postprandial glucose [-0.38 (-0.73, -0.02), -0.29 (-0.53, -0.04), respectively] and resistant starch type 2 intake improved fasting glucose [-0.39 (-0.66, -0.13)] and insulin [-0.40 (-0.60, -0.21)].

Conclusion

Resistant starch types 1 and 2 may influence glucose homeostasis via discrete mechanisms, as they appear to influence glycemia differently. Further research into resistant starch types 3, 4, and 5 is required to elucidate their effect on glucose metabolism. The addition of resistant starch as a dietary intervention for those with T2D or prediabetes may prevent further deterioration of glycemic control.

Influence of the gut microbiota on satiety signaling

Recent studies show a link between the gut microbiota and the regulation of satiety and energy intake, processes that contribute to the development and pathophysiology of metabolic diseases. However, this link is predominantly established in animal and in vitro studies, whereas human intervention studies are scarce. In this review we focus on recent evidence linking satiety and the gut microbiome, with specific emphasis on gut microbial short-chain fatty acids (SCFAs). Based on a systematic search we provide an overview of human studies linking the intake of prebiotics with gut microbial alterations and satiety signaling. Our outcomes highlight the importance of in-depth examination of the gut microbiota in relation to satiety and provide insights into recent and future studies in this field.

Enhanced secretion of satiety-promoting gut hormones in healthy humans after consumption of white bread enriched with cellular chickpea flour: A randomized crossover study

BACKGROUND

Dietary intake of pulses is associated with beneficial effects on body weight management and cardiometabolic health, but some of these effects are now known to depend on integrity of plant cells, which are usually disrupted by flour milling. Novel cellular flours preserve the intrinsic dietary fiber structure of whole pulses and provide a way to enrich preprocessed foods with encapsulated macronutrients.

OBJECTIVES

This study aimed to determine the effects of replacing wheat flour with cellular chickpea flour on postprandial gut hormones, glucose, insulin, and satiety responses to white bread.

METHODS

We conducted a double-blind randomized crossover study in which postprandial blood samples and scores were collected from healthy human participants (n = 20) after they consumed bread enriched with 0%, 30%, or 60% (wt/wt) cellular chickpea powder (CCP, 50 g total starch per serving).

RESULTS

Bread type significantly affected postprandial glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) responses (time × treatment, P = 0.001 for both). The 60% CCP breads elicited significantly elevated and sustained release of these anorexigenic hormones [between 0% and 60% CPP-GLP-1: mean difference incremental area under the curve (iAUC), 3101 pM/min; 95% CI: 1891, 4310; P-adjusted < 0.001; PYY: mean difference iAUC, 3576 pM/min; 95% CI: 1024, 6128; P-adjusted = 0.006] and tended to increase fullness (time × treatment, P = 0.053). Moreover, bread type significantly influenced glycemia and insulinemia (time × treatment, P < 0.001, P = 0.006, and P = 0.001 for glucose, insulin, and C-peptide, respectively), with 30% CCP breads eliciting a >40% lower glucose iAUC (P-adjusted < 0.001) than the 0% CCP bread. Our in vitro studies revealed slow digestion of intact chickpea cells and provide a mechanistic explanation for the physiologic effects.

CONCLUSIONS

The novel use of intact chickpea cells to replace refined flours in a white bread stimulates an anorexigenic gut hormone response and has potential to improve dietary strategies for prevention and treatment of cardiometabolic diseases. This study was registered at clinicaltrials.gov as NCT03994276.

Unlocking the Potential of High-Amylose Starch for Gut Health: Not All Function the Same

High-amylose starch has unique functional properties and nutritional values in food applications. This type of starch is generally resistant to enzymatic digestion in the gastrointestinal tract, and contains an increased fraction of resistant starch (RS), which is a type of dietary fiber. The digestion and fermentation of high-amylose starch in the gut are of current research interest, as the processes are related to its nutritional functionality. This review summarizes recent in vitro and in vivo studies on the digestion and fermentation of high-amylose starches from different botanical sources and those that have been obtained by modifications. The RS content and fermentation properties are compared among high-amylose starches. This review aims to provide a current understanding of the relationship between high-amylose starch structures and fermentation-related nutritional properties. The results of these studies suggest that both modifications and food processing of high-amylose starch result in distinct fermentation products and nutritional properties. The review provides insight into the potential future applications of diverse high-amylose starches as bioactive compounds to modulate colonic fermentation.

Acute postprandial gut hormone, leptin, glucose and insulin responses to resistant starch in obese children: a single blind crossover study

INTRODUCTION

Resistant starch (RS) has beneficial effects on postprandial glucose metabolism in both animals and adults. Hitherto, there have been no studies in children of the acute metabolic and hormonal effects of RS-containing meals.

OBJECTIVES

We aimed to compare serial plasma glucose, insulin, gut hormone, leptin profiles and satiety scores in obese children after meals containing variable amounts of RS.

METHODS

This was a single blind, non-randomised, crossover study of 20 obese children aged 10-14 years old without comorbidities. Three test meals containing rice (M1), rice cooked with coconut oil (M2), rice cooked in coconut oil with lentils (M3) were given in sequence after a 12-hour fast . Blood samples were analysed for glucose (PG), insulin, leptin, glucagon-like polypeptide (GLP) 1, ghrelin and peptide YY (PYY) at appropriate times between 0 and 180 min.

RESULTS

Meal M2 resulted in significantly lower postprandial glucose values compared with meal M1 (maximal incremental glucose, ∆C_max, p<0.05; area under the curve, ∆AUC_0-3, p<0.01) and meal M3 (maximal concentration, C_max, p<0.01; ∆C_max, p<0.001, and ∆AUC_0-3p<0.01). M2 also produced lower insulin values compared with M1 (p<0.05). Postprandial ghrelin was significantly higher after M1 compared with M3 (p<0.05). PYY, GLP1 and median satiety scores were not significantly different between the three meals.

CONCLUSION

This study shows that M2, the meal containing RS alone, induced beneficial effects on acute postprandial glucose, insulin and ghrelin concentrations in obese children without diabetes. Acute postprandial satiety scores were not significantly affected by the three meals.

TRIAL REGISTRATION NUMBER

SLCTR/2020/007.

The role of cereal soluble fiber in the beneficial modulation of glycometabolic gastrointestinal hormones

According to cohort studies, cereal fiber, and whole-grain products might decrease risk for type 2 diabetes (T2DM), inflammatory processes, cancer, and cardiovascular diseases. These associations, mainly affect insoluble, but not soluble cereal fiber. In intervention studies, soluble fiber elicit anti-hyperglycemic and anti-inflammatory short-term effects, partially explained by fermentation to short-chain fatty acids, which acutely counteract insulin resistance and inflammation. ß-glucans lower cholesterol levels and possibly reduce liver fat. Long-term benefits are not yet shown, maybe caused by T2DM heterogeneity, as insulin resistance and fatty liver disease - the glycometabolic points of action of soluble cereal fiber - are not present in every patient. Thus, only some patients might be susceptive to fiber. Also, incretin action in response to fiber could be a relevant factor for variable effects. Thus, this review aims to summarize the current knowledge from human studies on the impact of soluble cereal fiber on glycometabolic gastrointestinal hormones. Effects on GLP-1 appear to be highly contradictory, while these fibers might lower GIP and ghrelin, and increase PYY and CCK. Even though previous results of specific trials support a glycometabolic benefit of soluble fiber, larger acute, and long-term mechanistic studies are needed in order to corroborate the results.

Acute effect of Melon Manis Terengganu peel powder on glycemic response, perceived satiety, and food intake: a randomized, placebo-controlled crossover trial in adults at risk of type 2 diabetes

BACKGROUND

Melon Manis Terengganu (MMT) peel has a high dietary fiber content, but there is no data examining its health benefits in adults at risk of type 2 diabetes. The objective of the study was to evaluate whether consumption of MMT peel powder improves glycemic response, satiety, and food intake in adults at risk of type 2 diabetes.

METHODS

An open-label, randomized, placebo-controlled, crossover design trial was conducted among adults (n = 30, ages 18-59 y) at risk of type 2 diabetes. They consumed Formulation 3 (formulated MMT peel powder) [A] and control (glucose) [B] with study breakfast based on randomly assigned treatment sequences (AB, BA) established by Research Randomizer ( www.randomizer.org ). Capillary blood glucose and perceived satiety were determined at baseline (0 min), 30, 60, 90 and 120 min, followed by a post-intervention food intake measurement.

RESULTS

The repeated measures analysis of variance (ANOVA) revealed significant time (F = 84.37, p <  0.001, η_p² = 0.744), condition (F = 22.89, p <  0.001, η_p² = 0.441), and time*condition effects (F = 24.40, p <  0.001, η_p² = 0.457) in blood glucose levels. Respondents (n = 30) who consumed Formulation 3 also had a significantly lower blood glucose 2-hour incremental area under the curve (iAUC) of 134.65 ± 44.51 mmol/L*min and maximum concentration (CMax) of 7.20 (7.10, 8.20) mmol/L with relative reduction of 26.8 and 13.3% respectively, when compared with control (p <  0.001). Besides, significantly greater perceived satiety, lower energy and fat intake as well as higher dietary fiber intake were also observed in the intervention group compared with the placebo group (p <  0.05). There were no marked side effects associated with the ingestion of the test products.

CONCLUSIONS

Short-term consumption of formulated MMT peel powder may improve glycemic response, increase perceived satiety and reduce food intake in adults at risk of type 2 diabetes with the potential to be utilized as a functional beverage. Medium-to long-term clinical trial is warranted to determine whether taking this formulated MMT peel powder on a daily basis has an influence on health outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05298111. Registered 28/03/2022.

Substitution of Refined Conventional Wheat Flour with Wheat High in Resistant Starch Modulates the Intestinal Microbiota and Fecal Metabolites in Healthy Adults: A Randomized, Controlled Trial

BACKGROUND

Resistant starch (RS) confers many health benefits, mostly through the microbial production of SCFAs, but foods containing appreciable RS are limited. High-amylose wheat (HAW) is high in RS and lowers the glycemic response of foods, but whether it can improve gastrointestinal health measures is unknown.

OBJECTIVES

The objective of this study was to determine whether daily consumption of HAW food products improved markers of gastrointestinal health in healthy men and women compared with similar foods made from conventional wheat.

METHODS

Eighty healthy adults (47 women and 33 men) were enrolled in a 4-arm parallel, randomized-controlled, double-blind trial. After a 2-wk low-dietary fiber run-in period, they were randomly allocated to 1 of 4 treatment groups: low-amylose wheat (LAW)-refined (LAW-R), LAW-wholemeal (LAW-W), HAW-refined (HAW-R), and HAW-wholemeal (HAW-W) and consumed the assigned test bread (160 g/d) and biscuits (75 g/d) for 4 wk. Fecal biochemical markers were measured at baseline and 4 wk. Microbial abundance and diversity were quantified using 16S ribosomal RNA sequencing and perceived gut comfort by a semiquantitative questionnaire completed at baseline, 2 wk, and 4 wk.

RESULTS

HAW showed similar effects on fecal output and excretion of total SCFA compared with LAW, but changes were observed in secondary measures for the refined treatment groups. At 4 wk, the HAW-R group had 38% higher fecal butyrate excretion than the LAW-R group (P < 0.05), and higher fecal SCFA-producing bacteria, Roseburia inulinivorans (P < 0.001), than at baseline. In comparison with baseline, LAW-R increased fecal p-cresol concentration, and fecal abundance of a p-cresol-producing bacterium, Clostridium from the Peptostreptococcaceae family, but both were reduced by HAW-R. Amylose level did not affect measures of fecal consistency or adversely affecting digestive comfort.

CONCLUSIONS

Increasing RS intake of healthy adults by substituting refined conventional wheat with refined HAW modulates fecal metabolites and microbes associated with gastrointestinal health.This trial was registered at anzctr.org.au as ACTRN12618001060235.

Tolerability and SCFA production after resistant starch supplementation in humans: a systematic review of randomized controlled studies

BACKGROUND

Resistant starches (RSs) have been advocated as a dietary supplement to address microbiota dysbiosis. They are postulated to act through the production of SCFAs. Their clinical tolerability and effect on SCFA production has not been systematically evaluated.

OBJECTIVES

We conducted a systematic review of RS supplementation as an intervention in adults (healthy individuals and persons with medical conditions) participating in randomized controlled trials. The primary outcome was tolerability of RS supplementation, the secondary outcome was SCFA production.

METHODS

MEDLINE, Embase, and the Cochrane Central Register were searched. Articles were screened, and data extracted, independently and in duplicate.

RESULTS

A total of 39 trials met eligibility criteria, including a total of 2263 patients. Twenty-seven (69%) studies evaluated the impact of RS supplementation in healthy subjects whereas 12 (31%) studies included individuals with an underlying medical condition (e.g., obesity, prediabetes). Type 2 RS was most frequently investigated (29 studies). Of 12 studies performed in subjects with health conditions, 11 reported on tolerability. All studies showed that RS supplementation was tolerated; 9 of these studies used type 2 RS with doses of 20-40 g/d for >4 wk. Of 27 studies performed in healthy subjects, 20 reported on tolerability. In 14 studies, RS supplementation was tolerated, and the majority used type 2 RS with a dose between 20 and 40 g/d. Twenty-one (78%) studies reporting SCFAs used type 2 RS with a dose of 20-40 g/d for 1-4 wk. In 16 of 23 studies (70%), SCFA production was increased, in 7 studies there was no change in SCFA concentration before and after RS supplementation, and in 1 study SCFA concentration decreased.

CONCLUSIONS

Available evidence suggests that RS supplementation is tolerated in both healthy subjects and in those with an underlying medical condition. In addition, SCFA production was increased in most of the studies.

Resistant Starch Consumption Effects on Glycemic Control and Glycemic Variability in Patients with Type 2 Diabetes: A Randomized Crossover Study

We previously observed beneficial effects of native banana starch (NBS) with a high resistant starch (RS) content on glycemic response in lean and obese participants. Here, we aimed to determine the effects of NBS and high-amylose maize starch (HMS) on glycemic control (GC) and glycemic variability (GV) in patients with type 2 diabetes (T2D) when treatments were matched for digestible starch content. In a randomized, crossover study, continuous glucose monitoring (CGM) was performed in 17 participants (aged 28-65 years, BMI ≥ 25 kg/m², both genders) consuming HMS, NBS, or digestible maize starch (DMS) for 4 days. HMS and NBS induced an increase in 24 h mean blood glucose during days 2 to 4 (p < 0.05). CONGA, GRADE, and J-index values were higher in HMS compared with DMS only at day 4 (p < 0.05). Yet, NBS intake provoked a reduction in fasting glycemia changes from baseline compared with DMS (p = 0.0074). In conclusion, under the experimental conditions, RS from two sources did not improve GC or GV. Future longer studies are needed to determine whether these findings were affected by a different baseline microbiota or other environmental factors.

Effects of a Low Carb Diet and Whey Proteins on Anthropometric, Hematochemical, and Cardiovascular Parameters in Subjects with Obesity

BACKGROUND

The best way to lose body weight, without using drugs and/or suffering hunger and stress, has not yet been defined. The present study tested a low carbohydrate diet, enriched with proteins, in subjects with overweight and obesity.

METHODS

The study enrolled 22 uncomplicated overweight and obese subjects. Several parameters were examined before and after 6 weeks of a low-carbohydrate diet, enriched with 18 g of whey proteins. Anthropometric (body mass index, waist circumference) variables, fasting hormones (insulin, TSH, FT3, FT4), and metabolic (glucose, prealbumin, and lipid levels) parameters were measured. 25- OH-vitamin D (25 (OH) D), parathyroid hormone (PTH) and osteocalcin, were also quantified. Body composition parameters (fat mass, fat-free mass, body cell mass, total body water) were measured by electrical bioimpedance analysis. As cardiovascular parameters, blood pressure, endothelium flowmediated dilation (FMD), and common carotid artery intima-media thickness were also measured.

RESULTS

The low-carbohydrate diet integrated with proteins induced a significant decrease in body weight (P < 0.001), waist circumference (P < 0.001), fat mass (P < 0.001), diastolic blood pressure (P < 0.01), triglycerides (P < 0.001), total cholesterol (P < 0.001), pre-albumin (P < 0.001), insulin (P < 0.001), HOMAIR (P < 0.001), FT3 (P < 0.05), and c-IMT (P < 0.001), and a significant increase in FMD (P < 0.001) and 25 (OH) D (P < 0.001) was also observed.

CONCLUSION

All these results suggest that a short-term non-prescriptive low carbohydrate diet, enriched with whey proteins, may be a good way to start losing fat mass and increase health.

The effect of sorghum consumption on markers of chronic disease: A systematic review

Sorghum requires fewer inputs for sustainable cultivation in harsh climates and has the potential to be utilized in modern food product innovations. Moreover, consumption of sorghum may elicit favorable health effects similar to other commonly consumed cereals, like wheat. Animal and human research exploring health effects of sorghum consumption indicates potential beneficial effects on blood glucose and lipid regulation, oxidative stress modulation, appetite regulation and weight management. However, a recent appraisal of the strength of evidence has not been conducted. Therefore, this study aims to evaluate the effects of sorghum consumption on metabolic indicators of chronic disease, including blood lipid and blood glucose levels, markers of oxidative stress, and factors associated with weight management. Using CINAHL, Cochrane Library, PubMed and MEDLINE databases, a systematic review of intervention studies published up to May 2020 was conducted and 16 interventional studies met the criteria for inclusion. Evidence for favorable effects of sorghum consumption on indicators of chronic disease, including blood glucose responses, markers of oxidative stress, satiety measures and weight management was demonstrated. Evidence from this systematic review may assist to promote sorghum's potential health benefits globally, including in food markets where it is underutilized, stimulating more sorghum-based food innovations in the future.

Effect of biscuits formulated with high-amylose maize flour on satiety-related sensations and food intake

The amount of amylose within a food may elicit lower glycemic and insulin postprandial responses and thus potentially modulate the satiating effect. In this context, the effect of biscuits formulated with high amylose starch (HAS) flour on satiety-related sensations and food intake was studied. Three types of biscuits were produced: control biscuit (CRT, 0% of HAS), Amy-25 (25% HAS), and Amy-50 (50% HAS). Fifteen healthy volunteers were enrolled to conduct two in vivo experiments. In experiment 1, volunteers consumed biscuits ad libitum and their sensations of satiety and food intake were evaluated. In experiment 2, volunteers received a quantity of biscuits equivalent to the 20% of the daily estimated energy requirements, and both satiety-related sensations and food intake were checked at subsequent meal. The Amy-50 significantly reduced food intake at subsequent meal (p ˂ 0.05), compared to Amy-25 and CRT. The satiety-related sensations were not significantly affected in both experiments, excepted for intra-meal hunger variation induced by Amy-25 which resulted significantly higher (p ˂ 0.05) than Amy-50 and CRT. These findings support the need to reformulate carbohydrate rich foods commonly consumed in a dietary context, to provide consumers healthier alternatives to prevent and tackle obesity and related chronic diseases.

Resistant Starch Combined with Whey Protein Increases Postprandial Metabolism and Lowers Glucose and Insulin Responses in Healthy Adult Men

Resistant starch (RS) and/or protein consumption favorably influence energy metabolism, substrate utilization, and weight management. The current study administered four different versions of a pancake breakfast containing waxy maize or RS with and without whey protein (WP) and measured postprandial thermogenesis (TEM), fuel utilization, and circulating satiation and appetite factors for 180 min in a group of healthy, adult men. On four separate visits to the laboratory, eight participants were administered four different pancake breakfast meal challenges using a single-blind, randomized crossover design: (1) waxy maize starch (WMS) control; (2) WMS and WP (WMS + WP); (3) RS; or (4) RS and WP (RS + WP). TEM (kcals/180 min) was significantly greater (p < 0.05) in RS + WP (45.11; confidence interval (CI), 33.81–56.41) compared to WMS (25.61; CI, 14.31–36.91), RS (29.44; CI, 18.14–40.74), and WMS + WP (24.64; CI, 13.34–35.94), respectively. Fat oxidation was enhanced (p < 0.05) after RS + WP compared to RS at 60 min (+23.10%), WMS at 120 min (+27.49%), and WMS and WMS + WP at 180 min (+35.76%; +17.31%, respectively), and RER was decreased with RS + WP versus the other three meals (mean differences: ≥−0.021). Insulin concentrations were decreased (p < 0.05) following RS + WP compared to WMS, whereas both RS (−46.19%) and RS + WP (−53.05%) insulin area under the curve (AUC) were greatly reduced (p < 0.01) compared to WMS. While limited by sample size, meals containing both RS and WP increased postprandial thermogenesis and fat oxidation, and lowered insulin response compared to isocaloric meals without this combination. Therefore, RS + WP may favorably impact energy metabolism and thus weight control and body composition under chronic feeding conditions.

In vitro fermentation of flaxseed polysaccharide by fecal bacteria inhibits energy intake and adipogenesis at physiological concentration

Obesity and its related metabolic disorders have been a global pandemic. Recently, we found an anti-obesity effect of flaxseed polysaccharide (FP) that could be achieved by regulating intestinal microbiota. The anti-obesity effect of FP is mainly attributed to the metabolites produced by the interaction with FP, which remains to be elucidated. In this research, the in vitro effects of metabolites of FP fermented by fecal bacteria on energy metabolism and adipogenesis were investigated. The effect of energy metabolism was analyzed by mRNA and protein expression of the intestinal glucose transporters, including sodium dependent glucose transporter (SGLT1) and glucose transporter 2 (GLUT2), and glucose uptake in intestinal Caco-2 cells. The lipogenic effect were evaluated by Oil red O staining of intracellular lipid droplets and the mRNA and protein expression of peroxisome proliferator-activated receptor (PPAR) γ, CCAAT-enhancer-binding proteins (C/EBP) α and β in 3T3-L1 cells. The results showed the metabolites significantly inhibited glucose intake through downregulating the mRNA and protein expression of GLUT2 and SGLT1 in Caco-2 cells. Besides, they also led to the decrease of lipid accumulation through downregulating the mRNA and protein expression of PPARγ, C/EBPα, and C/EBPβ in differentiating adipocytes. The inhibitory effects on energy intake and adipogenesis were concentration dependent, and metabolites at physiological concentration showed the most significant effect. Metabolites of fecal bacteria fermenting FP inhibited energy intake and adipogenesis at physiological concentration, which might be one of the weight-loss mechanisms of FP-diet.

The effect of acute consumption of resistant starch on appetite in healthy adults; a systematic review and meta-analysis of the controlled clinical trials

BACKGROUND & AIMS

Although several clinical trials have assessed the effect of Resistant Starch (RS) supplementation on appetite, the results have been inconsistent. Therefore, this study aimed to assess the effect of RS on the healthy adults' rating of appetite.

MATERIALS AND METHODS

To this end, Pubmed, CENTRAL, Web of science, Scopus, Medline, and Proquest were systematically searched to find the relevant randomized, and placebo-controlled human trials up to June 2019. As a result, the area under curve (AUC) and standard deviations of the participants' rating appetite were extracted from four eligible studies.

RESULTS

Meta-analysis showed a lower appetite in RS group compared to the controls (weighted mean difference [WMD] = -1.375 mm min, 95% confidence interval [95%CI]: -1.673, -1.076). Since high heterogeneity was observed among the included studies (I² = 94.5%, P < 0.001), subgroup analysis was carried out by RS dose, RS type, duration of supplementation, and time of AUC measuring. In studies that used RS dose of ≥25 gr, heterogeneity disappeared (P = 0.560, I² = 0%). In such studies, a significant reduction was observed in rating of appetite (WMD = -4.513 mm min, 95%CI: -5.270, -3.755; P < 0.001) than studies with RS dose of <25 gr (WMD = -0.799 mm min, 95%CI: -1.123,-0.474; P < 0.001). Additionally, subgroup analysis based on the type of RS showed a significant decrease of appetite in studies that used RS2 (WMD = -4.808 mm min, 95%CI: -5.834, -3.782; P < 0.001) than RS1 (WMD = -0.128 mm min, 95%CI: -0.457, 0.202; P = 0.448).

CONCLUSIONS

To decrease the rate of appetite more effectively, we suggest other researchers to identify RS dose and type.

Western Diet: Implications for Brain Function and Behavior

The Western diet (WD) pattern characterized by high daily intake of saturated fats and refined carbohydrates often leads to obesity and overweight, and it has been linked to cognitive impairment and emotional disorders in both animal models and humans. This dietary pattern alters the composition of gut microbiota, influencing brain function by different mechanisms involving the gut-brain axis. In addition, long-term exposure to highly palatable foods typical of WD could induce addictive-like eating behaviors and hypothalamic-pituitary-adrenal (HPA) axis dysregulation associated with chronic stress, anxiety, and depression. In turn, chronic stress modulates eating behavior, and it could have detrimental effects on different brain regions such as the hippocampus, hypothalamus, amygdala, and several cortical regions. Moreover, obesity and overweight induce neuroinflammation, causing neuronal dysfunction. In this review, we summarize the current scientific evidence about the mechanisms and factors relating WD consumption with altered brain function and behavior. Possible therapeutic interventions and limitations are also discussed, aiming to tackle and prevent this current pandemic.

Modulating Phenolic Bioaccessibility and Glycemic Response of Starch-Based Foods in Wistar Rats by Physical Complexation between Starch and Phenolic Acid

This study assessed the impact of caffeic and ferulic acid complexation with maize amylopectin or potato starch on glycemic parameters. In comparison to starch-phenolic mixtures, starch-phenolic complexes resulted in significant modification of phenolic bioaccessibility and cellular uptake (p < 0.05). In addition, glucose release from in vitro digestion of starch was modestly reduced in the complexes compared to native starch alone (21.2-26.8 versus 29.8-30.5 mM). Furthermore, intestinal glucose transport, assessed in Caco-2 cell monolayers, was not affected by the presence of complexes (82.4-124 versus 100% at 90 min). However, a reduced glycemic response was evident in a Wistar rat model, with significant reduction in 240 min of blood glucose area under the curve following oral administration of the potato starch-ferulic acid complex compared to native potato starch (26 170 ± 556 versus 28 951 ± 486 mg min dL^-1; p < 0.001). These alterations were attributed to complexation-induced resistant starch formation and phenolic entrapment, providing an alternative mechanistic approach to modulate glycemic properties of starch-based foods.

Effects of potato resistant starch intake on insulin sensitivity, related metabolic markers and appetite ratings in men and women at risk for type 2 diabetes: a pilot cross-over randomised controlled trial

Background

The intake of certain types of resistant starch (RS) has been associated in some studies with increased whole‐body insulin sensitivity. This randomised, cross‐over pilot trial evaluated the effect of consuming cooked, then chilled potatoes, a source of RS, compared to isoenergetic, carbohydrate (CHO)‐containing control foods, on insulin sensitivity and related markers.

Methods

Nineteen adults with body mass index 27.0‐39.9 kg m⁻² consumed 300 g day⁻¹ RS‐enriched potatoes (approximately two potatoes; ~18 g RS) or CHO‐based control foods, as part of lunch, evening and snack meals, over a 24‐h period. After an overnight fast, insulin sensitivity, CHO metabolism markers, free fatty acids, breath hydrogen levels and appetite were assessed for up to 5 h after the intake of a standard breakfast. The primary endpoint was insulin sensitivity, assessed with the Matsuda index. P < 0.05 (one‐sided) was considered statistically significant.

Results

Insulin sensitivity was not significantly different between the potato and control conditions. The potato intervention resulted in higher postprandial breath hydrogen (P = 0.037), lower postprandial free fatty acid concentrations (P = 0.039) and lower fasting plasma glucose (P = 0.043) compared to the control condition. Fullness ratings were significantly lower after potato versus control (P = 0.002). No other significant effects were observed; however, there was a trend toward lower fasting insulin (P = 0.077) in the potato versus the control condition.

Conclusions

The results of this pilot study suggest RS‐enriched potatoes may have a favourable impact on carbohydrate metabolism and support the view that additional research in a larger study sample is warranted.

Higher Body Mass Index, Uric Acid Levels, and Lower Cholesterol Levels are Associated with Greater Weight Loss

Background:

Identifying predictive factors that contribute to changes in body weight may well be an interesting approach to the management of obesity.

Objective:

This study was firstly aimed at examining the effect of a one-year lifestyle program based on improvements in the habitual diet and increased levels of physical activity on weight loss. Secondly, it was focused on identifying anthropometric, and serum hormonal, metabolic and haematochemical factors which can be associated with the degree of weight loss in Kg.

Methods:

488 overweight or obese subjects, 383 women and 105 men, aged 18-67 years, were enrolled in the study. Body mass index, waist circumference, serum blood glucose, lipids, uric acid, creatinine, insulin, TSH, FT3, FT4, and 24-h urine catecholamines were measured.

Results:

Weight loss was positively associated with BMI (P < 0.01), waist circumference (P < 0.01), uric acid (P < 0.01), creatinine (P < 0.05), smoking (P < 0.01), and negatively correlated with age (P < 0.01), total cholesterol (P < 0.05), LDL-cholesterol (P < 0.01), HDL cholesterol (P < 0.05). In a multiple regression model considering weight loss as a dependent variable, and smoking, age, BMI, uric acid, creatinine, total cholesterol, LDL-cholesterol and HDL cholesterol as independent variables, weight loss maintained a direct independent relationship with BMI (P < 0.001), uric acid (P < 0.05), LDL-cholesterol (P < 0.05), and HDL-cholesterol (P < 0.05), and an inverse independent association with cholesterol (P < 0.01).

Conclusions:

This study suggests that higher BMI and uric acid levels, and lower total cholesterol concentrations are associated with a greater potential to lose weight.

Potato Preload Mitigated Postprandial Glycemic Excursion in Healthy Subjects: An Acute Randomized Trial

This study investigated the preload effect of the medium and high glycemic index (GI) potato, as well as the combination of partially hydrolyzed guar gum (HG) and potato, when ingested prior to a rice meal, on the iso-carbohydrate basis. In a randomized crossover trial, 17 healthy female subjects consumed (1) rice; (2) co-ingestion of highly cooked potato (HP), and rice (HP + R); (3) co-ingestion of minimally cooked potato (MP) and rice (MP + R); (4) preload HP prior to rice meal (PHP + R); (5) preload MP prior to rice meal (PMP + R); (6) co-ingestion of partially hydrolyzed guar gum (HG), HP and rice (HG + HP + R); (7) preload HG prior to co-ingestion of HP and rice (PHG + HP + R); (8) co-preload of HG and HP prior to rice (PHG + PHP + R); and (9) preload of HP prior to co-ingestion of HG and rice (PHP + HG + R). Postprandial glycemic response (GR) tests and subjective satiety tests were conducted for each test food. Cooked potato as a preload to a rice meal could significantly cut the acute postprandial glycemic excursion by around 1.0 mmol/L, irrespective of the GI of the preload. Co-preload of partial hydrolyzed guar gum and highly cooked potato (PHG + PHP + R) resulted in improved acute GR in terms of peak glucose value and glycemic excursion compared with either HG preload or HP preload. All the meals with preload showed comparable or improved self-reported satiety. Within an equicarbohydrate exchange framework, both high-GI and medium-GI potato preload decreased the postprandial glycemic excursion in young healthy female subjects. The combination of HG and HP as double preload resulted in better GR than both single HG or HP preload did.

Impact of dietary intake of resistant starch on obesity and associated metabolic profiles in human: a systematic review of the literature

As a global public health issue with an increasing prevalence, obesity is related to several metabolic disorders, but is largely preventable. Resistant starch (RS), the indigestible portion of starch, has been studied for its potential effects on reducing obesity. This systematic review aimed to investigate the effect of dietary intake of RS on obesity development and related metabolic profiles in human, including body weight and composition, energy intake and satiety, lipid profiles, blood glucose and insulin, and other blood biomarkers. Eleven peer-reviewed articles published in English between 2000 and 2019 were identified after screening using CENTRAL, MEDLINE, and CINAHL Plus. Based on the results, RS intake had no direct effect on body weight and body composition. Evidence for its effect on reducing energy intake and increasing satiety, as well as improving lipid profiles was inconsistent. Beneficial effects of RS intake on several blood biomarkers were supported, indicating its regulatory roles in blood glucose homeostasis, insulin sensitivity, and gut hormone concentrations. Specifically, five out of the eight articles measuring blood glucose reported a decrease in either fasting or postprandial glucose levels; two out of the three articles measuring insulin sensitivity indicated a significant improvement after RS supplementation; studies measuring gut hormone concentrations including glucagon-like peptide 1 (GLP-1), and peptide YY (PYY) also showed significant improvements after RS interventions. In conclusion, the effect of dietary intake of RS on obesity and its related metabolic complications was not conclusive. Further research with larger sample sizes and longer duration is warranted.

Resistant Starch Has No Effect on Appetite and Food Intake in Individuals with Prediabetes

BACKGROUND

Type 2 resistant starch (RS2) has been shown to improve metabolic health outcomes and may increase satiety and suppress appetite and food intake in humans.

OBJECTIVE

This study assessed whether 12 weeks of daily RS2 supplementation could influence appetite perception, food intake, and appetite-related gut hormones in adults with prediabetes, relative to the control (CTL) group.

DESIGN

The study was a randomized controlled trial and analysis of secondary study end points.

PARTICIPANTS/SETTING

Sixty-eight adults (body mass index ≥27) aged 35 to 75 years with prediabetes were enrolled in the study at Pennington Biomedical Research Center (2012 to 2016). Fifty-nine subjects were included in the analysis.

INTERVENTION

Participants were randomized to consume 45 g/day of high-amylose maize (RS2) or an isocaloric amount of the rapidly digestible starch amylopectin (CTL) for 12 weeks.

MAIN OUTCOME MEASURES

Subjective appetite measures were assessed via visual analogue scale and the Eating Inventory; appetite-related gut hormones (glucagon-like peptide 1, peptide YY, and ghrelin) were measured during a standard mixed-meal test; and energy and macronutrient intake were assessed by a laboratory food intake (buffet) test, the Remote Food Photography Method, and SmartIntake app.

STATISTICAL ANALYSES PERFORMED

Data were analyzed using linear mixed models, adjusting for treatment group and time as fixed effects, with a significance level of α=.05.

RESULTS

RS2 had no effect on subjective measures of appetite, as assessed by visual analogue scale (P>0.05) and the Eating Inventory (P≥0.24), relative to the CTL group. There were no effects of RS2 supplementation on appetite-related gut hormones, including glucagon-like peptide 1 (P=0.61), peptide YY (P=0.34), and both total (P=0.26) and active (P=0.47) ghrelin compared with the CTL. RS2 had no effect on total energy (P=0.30), carbohydrate (P=0.11), protein (P=0.64), or fat (P=0.37) consumption in response to a buffet meal test, relative to the CTL. In addition, total energy (P=0.40), carbohydrate (P=0.15), protein (P=0.46), and fat (P=0.53) intake, as quantified by the Remote Food Photography Method, were also unaffected by RS2, relative to the CTL.

CONCLUSIONS

RS2 supplementation did not increase satiety or reduce appetite and food intake in adults with prediabetes.

An introductory review of resistant starch type 2 from high-amylose cereal grains and its effect on glucose and insulin homeostasis

Refined carbohydrates result from milling techniques that remove the outer layers of a cereal grain and grind the endosperm into a flour ingredient that is devoid of dietary fiber. Technologies have been developed to produce high-amylose cereal grains that have a significantly higher resistant starch type 2 and thus dietary fiber content in the endosperm of the cereal grain, which has positive implications for human health. A review of the literature was conducted to study the effects of resistant starch type 2 derived from high-amylose grains on glucose and insulin response. While thousands of articles have been published on resistant starch, only 30 articles have focused on how resistant starch type 2 from high-amylose grains affects acute and long-term responses of glucose and insulin control. The findings showed that resistant starch has the ability to attenuate acute postprandial responses when replacing rapidly digestible carbohydrate sources, but there is insufficient evidence to conclude that resistant starch can improve insulin resistance and/or sensitivity.

Chilled Potatoes Decrease Postprandial Glucose, Insulin, and Glucose-dependent Insulinotropic Peptide Compared to Boiled Potatoes in Females with Elevated Fasting Glucose and Insulin

Resistant starch (RS) has been shown to improve postprandial glycemia and insulin sensitivity in adults with metabolic syndrome. RS is found naturally in potatoes, where the amount varies based on cooking method and serving temperature. Thirty females with a mean BMI of 32.8 ± 3.7 kg/m2, fasting glucose of 110.5 mg/dL, and insulin of 10.3 µIU/L, completed this randomized, crossover study. A quantity of 250 g of boiled (low RS) and baked then chilled (high RS) russet potatoes were consumed on two separate occasions. Glycemic (glucose and insulin) and incretin response, subjective satiety, and dietary intake were measured. Results showed that the chilled potato elicited significant reductions at 15 and 30 min in glucose (4.8% and 9.2%), insulin (25.8% and 22.6%), and glucose-dependent insulinotropic peptide (GIP) (41.1% and 37.6%), respectively. The area under the curve for insulin and GIP were significantly lower after the chilled potato, but no differences were seen in glucose, glucagon-like peptide-1, and peptide YY, or overall subjective satiety. A higher carbohydrate and glycemic index but lower fat diet was consumed 48-hours following the chilled potato than the boiled potato. This study demonstrates that consuming chilled potatoes higher in RS can positively impact the glycemic response in females with elevated fasting glucose and insulin.