Search Results (54)

Background/Objectives: Cephalic-phase insulin responses (CPIRs) are characterized as the pre-absorptive release of insulin triggered by sensory stimuli associated with eating or drinking. CPIRs are beneficial because they reduce postprandial elevations in blood glucose. Methods: We investigated whether the flavor of two different types of laboratory chow elicits a CPIR in mice (C57BL/6). Results: First, we tried unsuccessfully to replicate a prior report that a single bite from a familiar chow pellet elicits a CPIR. Second, we determined that a minimum of 15 s of chewing on a familiar chow was necessary to elicit a CPIR. Third, we asked whether the chow-induced CPIR required prior exposure to the same chow. We tested the responses to a standard and a purified chow, which had similar macronutrient compositions. Mice raised on standard chow generated a CPIR to standard chow but not the novel purified chow. After 4 (but not 2) weeks of exposure to the purified chow, however, the mice generated a CPIR to it. Likewise, mice raised on purified chow generated a CPIR to purified chow but not to the novel standard chow. After 2–4 weeks of exposure to standard chow, however, the mice conditioned a CPIR to it. It follows that mice had to condition CPIRs to each type of chow. Fourth, we established that olfactory impairment eliminated the conditioned CPIR to standard chow (when it was familiar), but not to purified chow (when it was familiar). Conclusions: The flavor of familiar chow reliably triggered a CPIR in mice, but this response had to be conditioned through dietary exposure. Olfaction was a critical component of the conditioned stimulus for standard but not purified chow. Full article

Background: Pelemir (Cephalaria syriaca) is a bitter-tasting ancestral legume with a high polyphenol content and emerging potential as a functional food ingredient. This study investigated the acute metabolic effects of pelemir-enriched bread in adults. Methods: In this two-phase non-randomized trial, 60 participants in three groups (n = 20 per group: healthy controls [HCs], individuals with obesity [OB], and individuals with type 2 diabetes [T2D]) consumed regular or pelemir-enriched bread on two separate test days. Postprandial glucose, insulin, C-peptide, GLP-1, PYY, ghrelin, leptin, triglyceride, and IL-6 were measured over 120 min. Subjective appetite ratings were evaluated using visual analog scales (VASs). The incremental area under the curve (iAUC) values were compared using Wilcoxon tests and linear mixed-effects models. Results: Pelemir-enriched bread significantly increased iAUCs for insulin (p = 0.014), C-peptide (p = 0.046), and GLP-1 (p = 0.039) compared to regular bread. There was no significant change in iAUC for glucose. Group-stratified analyses showed a higher postprandial iAUC of glucose, insulin, and C-peptide in the OB group compared to the HC group. VAS-based appetite ratings did not show significant changes in hunger, fullness, or desire to eat, but a borderline significant reduction was observed in prospective food consumption after pelemir-enriched bread (p = 0.050). Conclusions: Acute consumption of pelemir-enriched bread may modulate postprandial insulin and incretin responses. Its modest impact on subjective appetite regulation supports further investigation of pelemir as a functional food rich in polyphenols, especially in populations with metabolic dysfunction. Full article

Background/Objectives: Recent shifts in dietary patterns have led to reduced fiber consumption, corresponding with increasing rates of obesity and metabolic disorders. Barley-based cereals with high fiber content, particularly β-glucan, may provide superior metabolic and satiety benefits compared to corn-based alternatives. This study investigated whether barley-based cereals provide superior metabolic and satiety benefits compared to corn-based alternatives in overweight Korean adults. Methods: After selecting the most optimal cereal in the phase 1 study (acute postprandial research), a 6-week randomized controlled trial (RCT) was conducted in phase 2. In the phase 2 trial, overweight adults (n = 30; mean age of 43 ± 10.89 years; 36.7% female) were randomly assigned to consume either barley (n = 15) or corn cereal (n = 15) daily for 6 weeks. Participants consumed approximately 50 g of available carbohydrates (either barley or corn cereal) in 190 mL milk. Outcome measures included anthropometric parameters, fasting blood glucose, homeostasis model assessment of insulin resistance (HOMA-IR), postprandial glucose, subjective satiety, and gut health. Results: After 6 weeks, between-group comparisons revealed significant differences favoring the barley group in body weight (barley: −0.33 kg vs. corn: +0.85 kg; difference: −1.18 kg, p = 0.027), BMI (barley: −0.14 kg/m² vs. corn: +0.03 kg/m²; difference: −0.17 kg/m², p = 0.014), and glycated albumin (barley: −0.78% vs. corn: +0.09%; difference: −0.87%, p = 0.032). Within-group analyses showed that the barley group exhibited significant reductions in percent body fat (−1.03%, p = 0.004), waist circumference (−3.64 cm, p = 0.003), waist-to-hip ratio (−0.02, p = 0.012), glycated albumin (−0.78%, p = 0.029), and LDL cholesterol (−10.57 mg/dL, p = 0.033). Conversely, the corn group showed significant increases in body weight (+0.85 kg, p = 0.026) and percent body fat (+0.84%, p = 0.020), with a significant decrease in HDL cholesterol (−2.84 mg/dL, p = 0.020). Conclusions: Barley-based cereals offer significant metabolic and satiety benefits for overweight adults compared to corn-based alternatives. These findings suggest that barley-based cereals may be an effective dietary intervention for managing obesity and metabolic disorders. Full article

Background/Objectives: Stroke survivors with dysphagia are usually fed with different feeding routes ranging from oral to percutaneous endoscopic gastrostomy (PEG). However, the impact of the feeding route on the gastric myoelectric activity (GMA) is little-studied. This work examined the effect of feeding route on GMA changes in stroke survivors with dysphagia. Methods: This study included 50 patients (20% women) who were divided into three groups based on their feeding route: an oral group (n = 20), a nasogastric group (NGT) (n = 20), and a PEG group (n = 10). For all participants, a nutritional assessment was conducted, and the GMA was measured using a transcutaneous multichannel electrogastrogram (EGG) with a water load satiety test before and after water loading. The EGG-related parameters used in the analysis included the average power distribution by frequency region and the average dominant frequency (ADF). Results: The study sample experienced ischemic stroke (66%) or hemorrhagic stroke (34%). At the baseline phase, the PEG group exhibited significantly longer periods of normogastria compared to the NGT and oral groups. Moreover, protein intake was significantly higher in the PEG tube feeding group compared to the other groups. Based on the type of stroke, the ischemic stroke group showed significantly higher tachygastria periods during postprandial EGG recording (p = 0.022). The energy and protein consumptions were significantly higher in the hemorrhagic stroke group (p = 0.001, p = 0.028, respectively). Conclusions: The GMA pattern is distinctive for the type of stroke. The PEG feeding route showed more periods with normogastria and the best protein intake. Full article

Background and Objectives: Gestational diabetes mellitus (GDM), which is becoming increasingly common in contemporary society, is recognized for its considerable psychosocial impact on pregnant women throughout the perinatal phase. The purpose of this research was to explore the possible links between mental health status and dietary habits among pregnant women diagnosed with GDM, alongside examining how these factors correlate with clinical indicators like HbA1c measurements and the necessity for insulin therapy. Materials and Methods: The study included 82 pregnant participants, 37 with gestational diabetes mellitus and 45 without. Blood samples were collected from all participants for biochemical analysis, including fasting blood glucose, postprandial blood glucose, and HbA1c levels, which can be clinical indicators for the presence of gestational diabetes mellitus, and the need for insulin treatment was recorded. Then, participants completed a questionnaire collecting sociodemographic and clinical data as well as the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Salzburg Emotional Eating Scale (SEES), and REZZY Eating Disorders Scale (REZZY). Data were statistically analyzed. Results: A previous diagnosis of gestational diabetes was more frequent in the case group (18.9%) than in the control group (2.2%) (p = 0.020). OGTT positivity was detected in 56.8% of the case group, whereas all control participants had negative results (p < 0.001). There were no statistically significant differences between the two groups in psychological symptom scores or eating behavior assessments (p > 0.05). Conclusions: Pregnant women with gestational diabetes mellitus were observed to score higher on measures of anxiety, depression, and emotional eating, particularly in response to negative emotions. These findings may indicate a potential association between gestational diabetes and psychological or behavioral factors related to metabolic regulation during pregnancy. Full article

Untreated olive oil mill wastewater (OOMW) from conventionally farmed olives was used in bread production to create a new functional product. Two types of bread were developed with 50% OOMW (EXP-1) and 100% OOMW (EXP-2) replacing water. Two leavening processes were tested: sourdough inoculum (S) vs. biga-like inoculum (B), with controls (CTR) without OOMW addition. The doughs were monitored throughout the acidification process by measuring pH, total titratable acidity, and the development of key fermentative microorganisms. To assess the hygienic quality during fermentation, plate count techniques were employed. After baking, the breads were evaluated for various quality parameters, including weight loss, specific volume, crumb and crust colors, image analysis, and the presence of spore-forming bacteria. Volatile compounds released from the breads were identified using solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC/MS). Polyphenolic compounds were analyzed via liquid chromatography–mass spectrometry (LC-MS). To assess the functional properties of the final products, the breads were homogenized with synthetic human saliva and subjected to in vitro digestion. OOMW did not significantly affect the growth of yeasts and lactic acid bacteria (LAB) or the acidification process. However, in terms of the specific volume and alveolation, breads from the S process and OOMW had poor quality, while those from the B process had better quality. Experimental breads (EXP_B-1 and EXP_B-2) contained higher levels of alcohols (especially ethanol and isobutyl alcohol), carbonyl compounds (like benzaldehyde), esters (such as ethyl caproate and ethyl caprylate), and terpenes. OOMW introduced phenolic compounds like hydroxytyrosol, coumaric acid, caffeic acid, and trans-hydroxycinnamic acid, which were absent in CTR_B breads. Functionalization of EXP_B-1 and EXP_B-2 breads was demonstrated by a 2.4- and 3.9-fold increase in Trolox equivalents, respectively. However, OOMW did not reduce post-prandial hyper-glycemia, as starch digestibility was similar between CTR_B and EXP_B breads. The sensory analysis, which focused solely on the visual, structural, and olfactory characteristics of the breads, excluding taste testing to prevent potential health risks from residual pesticides, showed a high appreciation for EXP_B-1 and EXP_B-2 breads, scoring higher than CTR_B in the overall assessment. Full article

This study evaluated the impact of the food matrix on the bioaccessibility and hypoglycemic potential and antioxidant potential of betalains from red prickly pear juice (Opuntia spp.) after in vitro gastrointestinal digestion. Six aqueous model systems (AMSs) were formulated using a betalain extract combined with glucose, citric acid, mucilage, pectin, or all components, alongside three complex matrices, the fresh juice (FJ), a formulated beverage (BF), and a pasteurized formulated beverage (BP). In vitro digestion simulated the gastric and intestinal phases. The results showed that complex matrices (FJ, BF, and BP) enhanced betalain bioaccessibility, with FJ exhibiting the highest bioaccessibility (59%). Mucilage and pectin provided the strongest protection, reducing betalain degradation by 30% and 25%, respectively, while citric acid had a destabilizing effect. Pasteurization (BP) reduced betalain stability compared to FJ and BF. Antioxidant activity decreased post-digestion but remained higher in BF. Notably, FJ showed the highest inhibition of α-amylase (72%) and α-glucosidase (68%), surpassing acarbose (50–60% inhibition). These findings highlight the critical role of the food matrix, particularly mucilage and pectin, in stabilizing betalains through non-covalent interactions and enhancing their hypoglycemic potential. Red prickly pear juice emerges as a promising functional food for managing postprandial glucose levels, offering valuable insights for developing betalain-rich foods to address type 2 diabetes. Full article

Background: Calorie restriction is increasingly recognized as a strategy for glycemic management in type 2 diabetes mellitus (DM) by promoting weight loss and potentially achieving diabetes remission. This study evaluated the feasibility of a 12-week structured calorie-restricted dietary intervention based on healthy Korean dietary patterns for adults with early type 2 DM. Methods: Adults aged 18–60 years with a body mass index (BMI) greater than 25 kg/m² and a short duration of diabetes were recruited. The intervention comprised two phases: a 6-week weight loss phase, targeting a 3% reduction every two weeks, starting with an 800 kcal/day diet and increasing by 200 kcal per phase, with all meals provided via home delivery, followed by a 6-week self-managed weight maintenance period, preceded by a one-week reintroduction phase with meals provided. Results: Among 27 participants, 24 completed the intervention (89% retention). Mean weight reduction at 6 weeks was 6.4 kg (7.6%), primarily achieved during Phase 1 (5.1%). By 12 weeks, the average weight reduction further improved to 7.4 kg (8.7%). Dietary adherence ranged from 80% to 90%, with energy intake closely aligning with the prescribed targets. Non-achievers exhibited a smaller initial reduction (2.5 kg vs. 3.9 kg), with the gap persisting throughout the study. Postprandial glycemic response to a mixed meal (65% carbohydrate) significantly improved from baseline to week 5. Conclusions: This structured dietary intervention demonstrated substantial weight reduction and improved glycemic response in adults with type 2 DM, highlighting its feasibility and effectiveness as a guided strategy for weight management. Full article

This research paper investigates the phytochemical profile, antioxidant activity, antidiabetic potential, and antibacterial activity of Myrtus communis berries. Two extraction methods were employed to obtain the extracts: solid–liquid ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE). The extracts were characterized using spectrophotometric methods and Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC). The UAE extract exhibited higher total flavonoid and anthocyanin content, while the SFE extract prevailed in total phenolic content and antioxidant activity in the DPPH radical screening assay. RP-HPLC characterization identified and quantified several polyphenolic compounds. In the UAE extract, epigallocatechin was found in a concentration of 2656.24 ± 28.15 µg/g dry weight (DW). In the SFE extract, cafestol was the identified compound with the highest content at a level of 29.65 ± 0.03 µg/g DW. Both extracts contained several anthocyanin compounds, including cyanidin 3-O-glucoside chloride, cyanidin-3-O-rutinoside chloride, malvidin-3-O-glucoside chloride, pelargonidin 3-O-glucoside chloride, peonidin 3-O-glucoside chloride, and peonidin-3-O-rutinoside chloride. The antidiabetic potential was evaluated in vitro by measuring the inhibition of α-amylase from porcine pancreas (type I-A). The results highlighted the ability of myrtle berry extracts to inhibit α-amylase enzymatic activity, suggesting its potential as an alternative for controlling postprandial hyperglycemia. The UAE extract showed the lowest IC50 value among the two extracts, with an average of 8.37 ± 0.52 µg/mL DW. The antibacterial activity of the extracts was assessed in vitro against Bacillus spp., Escherichia coli, and Staphylococcus aureus using the disk diffusion method. Both myrtle berry extracts exhibited similar antibacterial activity against the tested bacterial strains. The results support further investigation of myrtle berries extracts as a potential ingredient in functional food formulation, particularly due to its antioxidant, antidiabetic, and antibacterial properties. Full article

Background/Objective: The oral contraceptive pill (OCP) is widely used by women worldwide, yet the influence of the OCP on carbohydrate metabolism remains under-investigated, with existing studies being few and largely cross-sectional. The study objective was to assess, for the first time, the effect of the combined OCP on postprandial glycaemic response to an oral glucose bolus, using a randomised crossover design. Methods: The effect of a combined monophasic OCP phase on glucose homeostasis and metabolic profile was investigated in 21 healthy young women, who were regular users of either androgenic or anti-androgenic OCP formulations. Plasma glycaemic markers (glucose, insulin and C-peptide) were assessed prior to a 60 g glucose drink (fasting) and for a further 4 h postprandially; once during the “active” (hormone-containing) pill phase and once during the “inactive” (hormone-free) pill phase of the OCP usage cycle. Results: Despite no change in fasting values, in androgenic pill users, postprandial glucose and insulin responses to an oral glucose bolus were ~100% and ~50% greater, respectively, during the active versus inactive phase. In contrast, in anti-androgenic pill users there was no significant change in response between the two OCP usage cycle phases. Conclusions: These findings highlight an acute, but potentially detrimental, influence of the combined OCP on glucose homeostasis, particularly in users of formulations containing androgenic progestogens. Given the high global prevalence of OCP use and increasingly common prolonged active pill regimens, which may continue for months, years or even decades, potential cumulative effects of such changes on metabolic risk demand further investigation. Full article

Ceratonia siliqua L. is a medicinal plant that has long been used in traditional Moroccan medicine to treat many diseases. This study aimed to assess the impact of the stages of the immature phase of carob pulp (M1, M2, M3, M4, and M5) on phytochemical composition, antioxidant activity, and antidiabetic activity of Ceratonia siliqua L. The identification of the phenolic profile by HPLC-UV/MS-MS and the study of the antidiabetic effect by in silico, in vitro, and in vivo studies were carried out for extracts with high contents of phenolic compounds from immature wild carob pulp from the communes of Timoulit (TM), Bin Elouidane (AW), and Ouaouizerth (TG) in the province of Azilal in the Béni Mellal-Khénifra region. The results revealed a gradual increase in total sugar content over the pulp’s ripening period, reaching a value of 2134 ± 56.23 mg GE/100 g fresh weight (FW) for TG. The three locations showed peak values for total polyphenol content (TPC), total flavonoid content (TFC), and total condensed tannin (TCT) at the M2 stage. AW had the highest concentrations of TPC (3819 ± 226.4 mg GAE/100 g FM), TFC (1034 ± 57.08 mg QE/100 g FM), and TCT (1472 ± 28.46 mg CE/100 g FM). The DPPH assay (7892 ± 296.1 mg TE/100 g FM) and the FRAP assay (278.2 ± 7.85 mg TE/100 g FM) both demonstrated that the TG zone is a highly potent antioxidant zone. In contrast, the AW site exhibited a markedly elevated value of 725.4 ± 103.6 mg TE/100 g FM in the ABTS assay. HPLC-UV-MS/MS analysis showed that the methanolic extracts of immature carob pulp (MEICP) from the three areas contained several different chemical compounds. The most prevalent were 3-O-p-coumaroyl-5-O-caffeoylquinic acid, quercetin 3-methyl ether, gallic acid, and galloylquinic acid. Immature carob pulp extract (ICPE) from AW showed the strongest in vitro inhibition of pancreatic α-amylase (IC₅₀ = 0.405 µg/mL) and TG extracts were most potent against intestinal α-glucosidase (IC₅₀ = 0.063 µg/mL). In vivo, AW, TG, and TM extracts significantly reduced postprandial glycemia in rats, with AW having the greatest effect. These results highlight the antidiabetic potential of ICPE. The 3-O-p-Coumaroyl-5-O-caffeoylquinic acid showed better affinity for α-amylase compared to acarbose and interacted significantly with several amino acid residues of the enzyme. Similarly, this molecule and 3,4-Dicaffeoylquinic acid demonstrated a strong affinity for α-glucosidase, suggesting their potential as natural inhibitors of enzymes involved in carbohydrate metabolism. Most of the compounds are not substrates of P-glycoprotein and exhibited high intestinal absorption. Furthermore, the majority of these compounds did not act as inhibitors or substrates of CYP450 enzymes, reinforcing their suitability for development as oral medications. These results underscore the potential of immature carob pulp as a promising antidiabetic agent. Full article

Over 50% of patients who take statins are still at risk of developing atherosclerotic cardiovascular disease (ASCVD) and do not achieve their goal LDL-C levels. This residual risk is largely dependent on triglyceride-rich lipoproteins (TRL) and their remnants. In essence, remnant cholesterol-rich chylomicron (CM) and very-low-density lipoprotein (VLDL) particles play a role in atherogenesis. These remnants increase when lipoprotein lipase (LPL) activity is inhibited. ApoCIII has been thoroughly studied as a chief inhibitor and therapeutic options to curb its effect are available. On top of apoCIII regulation of LPL activity, there is a more precise control of LPL in various tissues, which makes it easier to physiologically divide the TRL burden according to the body’s requirements. In general, oxidative tissues such as skeletal and cardiac muscle preferentially take up lipids during fasting. Conversely, LPL activity in adipocytes increases significantly after feeding, while its activity in oxidative tissues decreases concurrently. This perspective addresses the recent improvements in our understanding of circadian LPL regulations and their therapeutic implications. Three major tissue-specific lipolysis regulators have been identified: ANGPTL3, ANGPTL4, and ANGPTL8. Briefly, during the postprandial phase, liver ANGPTL8 acts on ANGPTL3 (which is released continuously from the liver) to inhibit LPL in the heart and muscle through an endocrine mechanism. On the other hand, when fasting, ANGPTL4, which is released by adipocytes, inhibits lipoprotein lipase in adipose tissue in a paracrine manner. ANGPTL3 inhibitors may play a therapeutic role in the treatment of hypertriglyceridemia. Several approaches are under development. We look forward to future studies to clarify (a) the nature of hormonal and nutritional factors that determine ANGPTL3, 4, and 8 activities, along with what long-term impacts may be expected if their regulation is impaired pharmacologically; (b) the understanding of the quantitative hierarchy and interaction of the regulatory actions of apoCIII, apoAV, and ANGPTL on LPL activity; (c) strategies for the safe and proper treatment of postprandial lipemia; and (d) the effect of fructose restriction on ANGPTL3, ANGPTL4, and ANGPTL8. Full article

Food can change various physiological parameters along the gastrointestinal tract, potentially impacting postprandial drug absorption. It is thus important to consider different in vivo conditions during in vitro studies. Therefore, a novel dissolution medium simulating variable postprandial pH values and lipid concentrations was developed and used in this study. Additionally, by establishing and validating a suitable analytical method, the effects of these parameters on the dissolution of a model drug, cinnarizine, and on its distribution between the lipid and aqueous phases of the medium were studied. Both parameters, pH value and lipid concentration, were shown to influence cinnarizine behavior in the in vitro dissolution studies. The amount of dissolved drug decreased with increasing pH due to cinnarizine’s decreasing solubility. At pH values 5 and 7, the higher concentration of lipids in the medium increased drug dissolution, and most of the dissolved drug was distributed in the lipid phase. In all media with a lower pH of 3, dissolution was fast and complete, with a significant amount of drug distributed in the lipid phase. These results are in accordance with the in vivo observed positive food effect on cinnarizine bioavailability described in the literature. The developed medium, with its ability to easily adjust the pH level and lipid concentration, thus offers a promising tool for assessing the effect of co-ingested food on the dissolution kinetics of poorly soluble drugs. Full article

Intermittent energy-restricted diets have shown improved metabolic health and alterations in postprandial glucose and lipid responses. Given these diets’ inherent low carbohydrate content due to fasting and carbohydrates’ crucial role in postprandial metabolism, it is essential to determine if the observed benefits are primarily due to decreased carbohydrate consumption. This study aims to evaluate the acute metabolic effects of carbohydrate restriction on postprandial substrate metabolism, both in the presence and absence of energy restriction, compared to an iso-caloric balanced diet. Twelve (six male) healthy adults (27.33 ± 1.82; 26.64 ± 1.64 kg/m²) participated in this acute, three-arm crossover study. Participants consumed three pre-prepared intervention diets for one day (36 h), each separated by a 5-day washout period: a normal-carbohydrate (55% of energy) energy-balanced diet (nEB), a low-carbohydrate (50 g/day) energy-balanced (100% energy) diet (LCEB), and a low-carbohydrate (50 g/day) energy-restricted (25% energy) diet (LC25). Following each 36 h diet phase, blood metabolites were measured in the morning fasted state and serially across 360 min postprandially. Concurrently, substrate utilization (RQ) and energy expenditure were evaluated using indirect calorimetry. Data were analysed using repeated-measures ANOVA and Wilcoxon signed-ranks, with results displayed as mean ± SEM. Resting energy expenditure and postprandial thermogenesis showed no significant difference across the three study arms (p > 0.05) although RQ was markedly decreased in both LC arms (p < 0.001). Elevated hepatic 3-β-hydroxybutyrate production was observed in both low-carb groups compared to control (p < 0.01). Following 36 h of both low-carbohydrate diet improved postprandial TAG levels (p < 0.001). However, glucose tolerance was impaired in both low-carb diets (p = 0.04), while insulin responses showed no statistical difference between all diets (p > 0.05). Fasted and postprandial NEFA levels increased in both low-carb diets (p = 0.02, p < 0.01, respectively). Similarly, fasting GLP-1 levels rose in low-carb arms (p < 0.5), declining postprandially (p < 0.05). No significant difference was found between them in all analysed parameters (p < 0.05). This data suggest that limiting carbohydrates without concurrent energy restriction can mimic the short-term metabolic effects of fasting. Further research is needed to evaluate the long-term impacts of intermittent low-carb diets and their viability as alternatives to traditional energy-restricted plans, factoring in tolerance, sustainability, and lasting physiological effects. Full article

Background and objectives: Oral processing behavior is suggested to modulate metabolic responses to foods. In this study, we examined the impact of variations in oral processing characteristics during bread consumption on appetite and postprandial metabolic responses. Methods: Thirty healthy, normal-weight participants consumed three types of bread, differing in the leavening agent, in a randomized cross-over trial, while being video recorded to determine specific oral processing behaviors. At each study visit, gastric emptying, subjective appetites, and glucose and c-peptide levels were measured at regular time points for 4 h. After 4 h, the ad libitum energy intake was measured. The average values of each outcome were calculated to derive a single characteristic value per participant across the three types of bread. Results: A Spearman’s correlation analysis showed that the participant age was associated with a faster eating rate (r = 0.562, p = 0.001), a shorter oral exposure time (r = −0.569, p = 0.001), and less chews/bites (r = −0.387, p = 0.034). As expected, a slower eating rate was correlated with more chews per bite (r = −0.603, p < 0.001). Surprisingly, higher hunger ratings before bread consumption were associated with a smaller bite size (r = −0.518, p = 0.003). More chews/bites were associated with a higher AUC of C-peptide during the first 30 min after consumption (r = 0.398, p = 0.036). Oral processing behavior did not correlate with appetite, the energy intake in the subsequent meal, gastric emptying, or the glucose response (p > 0.05) to bread. However, slower gastric emptying was associated with a lower glucose AUC_30min (r = −0.453, p = 0.015) and c-peptide AUC_30min (r = −0.631, p < 0.001). Discussion: Although, overall, the metabolic responses to bread consumption were not affected by oral processing, thorough mastication of bread stimulated the cephalic phase of digestion, resulting in early release of insulin. This is in line with the existing literature, according to which anticipatory sight, smell, and taste of food can initiate the cephalic phase of insulin secretion, which is further enhanced by chewing and swallowing the food. However, the importance of the cephalic phase insulin release in overall glucose regulation is still unclear. Further research is needed to investigate to what extent and according to which mechanisms natural variations in oral processing can affect postprandial metabolic responses to food. Full article