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Background: Functional dyspepsia (FD) is most often a meal-induced syndrome. Studies using resting-state functional magnetic resonance imaging (rs-fMRI) reported abnormal connectivity in areas related to pain processing in FD. However, only a few studies have attempted to determine how meal ingestion affects the brain’s working patterns. Through rs-fMRI, this study observed how meal ingestion affected brain regions related to visceral hypersensitivity and emotional response networks in FD patients. Methods: A total of 30 FD patients and 32 healthy controls (HC) were enrolled and underwent clinical investigations. Rs-fMRI was performed twice after a 4-h fast and 50 min after a meal. The mean functional connectivity strength (FCS) values were extracted from brain regions with significant differences to show the trend of changes related to meal ingestion after FCS analyses. Results: Depression, anxiety, sleep disturbances, and weight loss were more common in FD patients (P ≤ 0.001). Compared with HCs (corrected cluster P-value < 0.05), FD patients had significantly higher FCS in the right middle frontal gyrus before meals and higher meal-induced FCS in the left postcentral gyrus. HCs had greater meal-induced activation in the right precuneus and anterior cingulate cortex. FD patients had a decreasing trend in the right inferior frontal gyrus compared to the increasing trend in HCs. We only found anxiety to be negatively correlated with FCS in the right inferior frontal gyrus in FD (r = −0.459, p = 0.048, uncorrected). Conclusions: In this study, we discovered that FD patients have different perceptual and emotional responses to food intake in defined brain areas, providing promising impetus for understanding pathogenic brain mechanisms in FD. [ABSTRACT FROM AUTHOR]

We recently reported interrelated digestive, cognitive, and hedonic responses to a meal. The aim of this study was to identify brain networks related to the hedonic response to eating. Thirty-eight healthy subjects (20-38 age range) were evaluated after a 5-hour fast and after ingestion of a test meal (juice and warm ham and cheese sandwich, 300 mL, 425 kcal). Perceptual and affective responses (satiety, abdominal fullness, digestive well-being, and positive mood), and resting scans of the brain using functional MRI (3T Trio, Siemens, Germany) were evaluated immediately before and after the test meal. A high-order group independent component analysis was performed to investigate ingestion-related changes in the intrinsic connectivity of brain networks, with a focus on thalamic and insular networks. Ingestion induced satiation (3.3±0.4 score increase; P

Background & Aims: For a healthy food to be introduced to the consumer's diet, it has to be attractive, yet testing for food acceptance and the sensory postprandial responses is still not standardized. The main objective of this study was to demonstrate that healthier foods can be obtained without impact on the responses to ingestion. Methods: A randomized, cross-over, double-blind, pilot study in non-obese, healthy men (n=8) comparing the responses to a standard sausage rich in animal fat (mortadella) versus a modified product based on a plant-derived fat analogue and an aroma. Palatability and postprandial sensations were measured on 10 cm scales and brain activity was evaluated by functional magnetic resonance imaging before and after each meal on separate days. Results: Both meals were rated equally palatable and induced the same degree of homeostatic sensations (satiety, fullness) with a similar hedonic dimension (improved mood and digestive well-being). Both meals induced similar changes in brain connectivity: decreased activity in the frontal-parietal, basal ganglia and thalamus, visual occipital, sensory-motor, temporal superior and in the "default-mode" networks, while increased activity was detected in the network associated with white matter. Conclusion: A substantial improvement in the nutritional profile of food can be achieved without affecting the responses to ingestion. [ABSTRACT FROM AUTHOR]

Objective: Meal ingestion is followed by a redistribution of blood flow (BF) within the splanchnic region contributing to nutrient absorption, insulin secretion and glucose disposal, but factors regulating this phenomenon in humans are poorly known. The aim of the present study was to evaluate the organ-specific changes in BF during a mixed-meal and incretin infusions. Design: A non-randomized intervention study of 10 healthy adults to study splanchnic BF regulation was performed. Methods: Effects of glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) infusions and mixed-meal were tested in 10 healthy, glucose tolerant subjects using PET-MRI multimodal imaging technology. Intestinal and pancreatic BF and blood volume (BV) were measured with 15O-water and 15O-carbon monoxide, respectively. Results: Ingestion of a mixed-meal led to an increase in pancreatic and jejunal BF, whereas duodenal BF was unchanged. Infusion of GIP and GLP-1 reduced BF in the pancreas. However, GIP infusion doubled blood flow in the jejunum with no effect of GLP-1. Conclusion: Together, our data suggest that meal ingestion leads to increases in pancreatic BF accompanied by a GIP-mediated increase in jejunal but not duodenal blood flow.

Postprandial objective abdominal distention is frequently associated with a subjective sensation of abdominal bloating, but the relation between both complaints is unknown. While the bloating sensation has a visceral origin, abdominal distention is a behavioral somatic response, involving contraction and descent of the diaphragm with protrusion of the anterior abdominal wall. Our aim was to determine whether abdominal distention influences digestive sensations. In 16 healthy women we investigated the effect of intentional abdominal distention on experimentally induced bloating sensation (by a meal overload). Participants were first taught to produce diaphragmatic contraction and visible abdominal distention. After a meal overload, sensations of bloating (0 to 10) and digestive well-being (−5 to + 5) were measured during 30-s. maneuvers alternating diaphragmatic contraction and diaphragmatic relaxation. Compared to diaphragmatic relaxation, diaphragmatic contraction was associated with diaphragmatic descent (by 21 + 3 mm; p < 0.001), objective abdominal distension (32 + 5 mm girth increase; p = 0.001), more intense sensation of bloating (7.3 + 0.4 vs. 8.0 + 0.4 score; p = 0.010) and lower digestive well-being (−0.9 + 0.5 vs. −1.9 + 0.5 score; p = 0.028). These results indicate that somatic postural tone underlying abdominal distention worsens the perception of visceral sensations (ClinicalTrials.gov ID: NCT04691882).

The neural mechanisms underlying subjective responses to meal ingestion remain incompletely understood. We previously showed in healthy men an increase in thalamocortical, and a decrease in insular-cortical connectivity in response to a palatable meal. As sex is increasingly recognized as an important biological variable, we aimed to evaluate sex differences and commonalities in the impact of a well-liked meal on thalamic and anterior insular connectivity in healthy individuals. Participants (20 women and 20 age-matched men) underwent resting-state magnetic resonance imaging (rsMRI) before and after ingesting a palatable meal. In general, the insula showed extensive postprandial reductions in connectivity with sensorimotor and prefrontal cortices, while the thalamus showed increases in connectivity with insular, frontal, and occipital cortices, in both women and men. However, reductions in insular connectivity were more prominent in men, and were related to changes in meal-related sensations (satiety and digestive well-being) in men only. In contrast, increases in thalamic connectivity were more prominent in women, and were related to changes in satiety and digestive well-being in women only. These results suggest that brain imaging may provide objective and sex-specific biomarkers of the subjective feelings associated with meal ingestion.

Splanchnic blood flow changes dramatically after meal ingestion. The present study evaluated physiologic interactions between meal ingestion and hemodynamics with respect to renal blood flow on duplex sonography, assessing the possible influence on Doppler parameters used as diagnostic criteria for renal artery stenosis. Subjects comprised 26 healthy young men (mean age: 22 ± 2 y). Sonographic measurements were made shortly after breakfast and every 1 h thereafter and were compared with values measured before the meal. Peak systolic velocity in the renal artery was elevated post-prandially, peaking at 1 h (90 ± 12 cm/s), compared with pre-prandially (73 ± 10 cm/s, p < 0.01). Similarly, acceleration time at the intra-renal segmental artery shortened to a minimum at 1 h (45 ± 5 ms) compared with baseline (51 ± 6 ms, p < 0.01). The present study indicates that renal blood flow is altered for a few hours after meal ingestion. Attention should be paid to the interpretation of data measured after meals on duplex sonography for diagnosis of renal artery stenosis. [ABSTRACT FROM AUTHOR]

Abstract: Background: Palatability of meals with identical composition has been shown to influence postprandial sensations. Our aim was to determine to what extent meal composition influences postprandial sensations independently of palatability. Methods: Randomized, crossover, double‐blind trial comparing the postprandial responses to a low‐fat vs a high‐fat test meal, with the same physical and organoleptic characteristics (taste, smell, texture, color, and temperature). The test meal consisted in 150 g hummus containing either 17.7 g fat (low‐fat) or 22.3 g fat (high‐fat), 19.8 g toasts, 120 mL water and 50 g apple puree. In 12 non‐obese healthy men, palatability, homeostatic sensations (hunger/satiety, fullness) and hedonic sensations (digestive well‐being, mood) were measured on 10 cm scales before and during the 60‐min postprandial period. Comparisons between meals were performed with a two‐way repeated measures ANCOVA with premeal data as co‐variate. Key Results: Both test meals were rated equally palatable (palatability scores 3.8 ± 0.3 low‐fat, 3.3 ± 0.2 high‐fat; P = .156). As compared to the high‐fat meal, the low‐fat meal induced more satisfaction (meal effect on well‐being F(1,21) = 4.92; P = .038) and tended to improve mood (meal effect F(1,21) = 3.02; P = .064), and this was associated with a non‐significant decrease in satiety (meal effect F(1,21) = 2.29; P = .145) and fullness (meal effect F(1,21) = 1.57; P = .224). Conclusions and Inferences: The composition of meals with equal palatability influences postprandial satisfaction, even without significant impact on homeostatic sensations, although an effect on homeostatic sensations has not been excluded. These conditioning factors may have clinical implications in patients with impaired meal tolerance or meal‐related symptoms. [ABSTRACT FROM AUTHOR]

Abstract: Background: The biological response to a meal includes physiological changes, primarily related to the digestive process, and a sensory experience, involving sensations related to the homeostatic control of food consumption, eg, satiety and fullness, with a hedonic dimension, ie associated with changes in digestive well‐being and mood. The responses to a meal include a series of events before, during and after ingestion. While much attention has been paid to the events before and during ingestion, relatively little is known about the postprandial sensations, which are key to the gastronomical experience. Purpose: The aim of this narrative review is to provide a comprehensive overview and to define the framework to investigate the factors that determine the postprandial experience. Based on a series of proof‐of‐concept studies and related information, we propose that the biological responses to a meal depend on the characteristics of the meal, primarily its palatability and composition, and the responsiveness of the guest, which may be influenced by multiple previous and concurrent conditioning factors. This information provides the scientific backbone to the development of personalized gastronomy. [ABSTRACT FROM AUTHOR]

Abstract: Background: Food palatability has been shown to influence satiation and meal consumption; our aim was to determine its effects on postprandial satisfaction, ie digestive well‐being (primary outcome), and homeostatic sensations (satiety, fullness). Methods: Randomized, cross‐over trial comparing the postprandial responses to conventional (potato‐cheese cream followed by vanilla cream) vs unconventional test meals (mixture of both creams) with identical composition and physical characteristics (color, texture, consistency, temperature) but distinctively different palatability. In 22 non‐obese healthy men sensations were measured on 10 cm scales before and during the 60‐min postprandial period (−5 to +5 score scales for palatability, satiety, well‐being, and mood, and 0‐10 score scales for fullness and discomfort). Comparisons between meals were performed with a 2‐way repeated measures ANCOVA with premeal data as co‐variate. Key Results: As compared to the palatable conventional meal, the unconventional meal was rated unpalatable (−1.8 ± 0.4 score vs 2.8 ± 0.1 score potato cream and 2.9 ± 0.2 vanilla cream; P < .001 for both), induced significantly more fullness sensation [meal effect F (1, 19) = 7.389; P = .014] but had less effect on digestive well‐being [meal effect F (1, 19) = 47.016; P < .001] and mood [meal‐effect F (1, 19) = 6.609; P = .019]. The difference in satiety was not significantly different. Conclusion & Inferences: Meal palatability influences the postprandial experience: it bears a direct relation to the hedonic response (well‐being/mood) but an inverse relation to homeostatic sensations (fullness). These relations could be applicable to influence eating behavior, because at equal conditions, more palatable meals induce less fullness but more satisfaction, and vice‐versa. [ABSTRACT FROM AUTHOR]

Abstract: Background: Ingestion of a meal induces homeostasis‐related sensations (satiety/fullness) that have a hedonic dimension (satisfaction/mood). We have previously shown that a previous physiological intervention, a meal preload, influences the responses to a subsequent meal, specifically: it increases satiety/fullness and decreases satisfaction. We now wished to determine the differential effects of education on the homeostatic and hedonic postprandial experience. Methods: Randomized, parallel study comparing the effect of real vs sham education on the responses to a probe meal. In two groups of healthy subjects (n = 14 each), homeostatic (satiety, fullness) and hedonic sensations (digestive well‐being, mood) in response to a probe meal (250 mL soup, 25 g bread) were measured on 2 separate days before and after a single sensory‐cognitive educational intervention (taste recognition test of supra‐ and sub‐threshold tastands for real and sham education, respectively). Key Results: Before education, in both groups the probe meal induced homeostatic sensations (satiety, fullness) with a positive hedonic dimension (increased digestive well‐being and mood). In contrast to sham education, real education enhanced both homeostatic and hedonic responses to the probe meal (P < .05 vs sham education for all). Conclusions and Inferences: Education modifies the subjects′ receptiveness and influences the responses to a meal, not only the hedonic postprandial experience, but also homeostatic sensations. Since homeostatic and hedonic responses are dissociable, education might be tailored to target different conditions. [ABSTRACT FROM AUTHOR]

In a previous study, we demonstrated that women enjoyed and tolerated lower meal loads than men. Hence, we hypothesized that with the same meal load, their postprandial response is more pronounced than in men. We performed a randomized parallel trial in 12 women and 12 men comparing the postprandial responses to a palatable comfort meal. We measured homeostatic sensations (hunger/satiety, fullness) and hedonic sensations (digestive well-being, mood) on 10 cm scales, vagal tone by heart ratio variability and the metabolomic profile before and after meal ingestion. Gender differences were analyzed by repeated measures ANCOVA. Overall (n = 24), ingestion of the probe meal induced satiation, fullness, digestive well-being and improved mood (main time-effect p ≤ 0.005 for all). Women exhibited a more intense sensory experience, specially more postprandial fullness, than men [main gender-effect F (1, 21) = 7.14; p = 0.014]; hedonic responses in women also tended to be stronger than in men. Women exhibited more pronounced effects on vagal tone [main gender-effect F (1, 21) = 5.5; p = 0.029] and a different lipoprotein response than men. In conclusion, our data indicate that gender influences the responses to meal ingestion, and these differences may explain the predisposition and higher incidence in women of meal-related functional disorders.

Ingestion of a meal induces conscious sensations depending of the characteristics of the meal and the predisposition of the eater. We hypothesized that the eating schedule plays a conditioning role, specifically, that an extemporaneous meal is less rewarding than when eaten at the habitual schedule. We conducted a randomized parallel trial in 10 women and 10 men comparing the responses to a consistent savoury lunch-type meal (stewed beans) eaten at the habitual afternoon schedule or at an unconventional time in the morning. Schedule and gender differences were analyzed by repeated measures analysis of covariance. In women, the sensory experience induced by the probe meal, particularly postprandial satisfaction, was weaker when eaten at an unconventional time for breakfast. Men were resilient to the schedule effect and experienced the same sensations regardless of the timing of ingestion; the effect of the eating schedule was significantly more pronounced in women for fullness (F(1,55) = 14.9; p < 0.001), digestive well-being (F(1,36.8) = 22.3; p < 0.001), mood (F(1,12.4) = 13.8; p < 0.001), and anxiety (F(1,11.9) = 10.9; p = 0.001). No differences in the physiological responses induced by the afternoon and morning meals were detected either in women or men. Our data indicate that women are more susceptible to changes in meal schedule than men.

Various conditioning factors influence the sensory response to a meal (inducible factors). We hypothesized that inherent characteristics of the eater (constitutive factors) also play a role. The aim of this proof-of-concept study was to determine the role of gender, as an individual constitutive factor, on the meal-related experience. Randomized parallel trial in 10 women and 10 men, comparing the sensations before, during, and after stepwise ingestion of a comfort meal up to full satiation. Comparisons were performed by repeated Analysis of Covariance (ANCOVA) measures. During stepwise ingestion, satisfaction initially increased up to a peak, and later decreased down to a nadir at the point of full satiation. Interestingly, the amount of food consumed at the well-being peak was lower, and induced significantly less fullness in women than in men. Hence, men required a larger meal load and stronger homeostatic sensations to achieve satisfaction. The same pattern was observed at the level of full satiation: men ate more and still experienced positive well-being, whereas in women, well-being scores dropped below pre-meal level. The effect of gender on the ingestion experience suggests that other constitutive factors of the eater may also influence responses to meals.

Background We have previously shown that the postprandial experience includes cognitive sensations, such as satiety and fullness, with a hedonic dimension involving digestive well-being and mood. Preload conditioning has been shown to modulate appetite and food consumption under certain conditions, but its effects on the responses to meal ingestion are not clear. We hypothesized that appetite modulation by preload conditioning has differential effects on the cognitive and the emotive responses to meal ingestion. Methods The effects of preload conditioning (ingestion of a low- vs a high-calorie breakfast) on appetite and on the cognitive and emotive responses to a comfort probe meal ingested 2 hours later (ham and cheese sandwich with orange juice; 300 mL, 425 Kcal) was tested in healthy subjects (n=12) in a cross-over design. Sensations were measured at regular intervals 15 minutes before and 60 minutes after the probe meal. Key Results As compared to the low-calorie breakfast, the high-calorie breakfast reduced basal hunger sensation and influenced the responses to the subsequent probe meal: it increased satiety (4.3±0.2 score vs 2.7±0.2 score; P<.001) and fullness (5.4±0.5 score vs 3.1±0.5; P<.001), but reduced the expected postprandial experience of digestive well-being after a palatable meal (1.3±0.7 score vs 3.0±0.3; P=.045). Conclusion and Inferences Appetite modulation by preload conditioning has differential effects on the cognitive and emotive responses to a meal. Preload conditioning of the postprandial experience may be applicable to dietary planning and prevention of postprandial symptoms. [ABSTRACT FROM AUTHOR]

Background Ingestion of a meal induces cognitive and hedonic sensations and our aim was to determine the relation between both dimensions. Methods In three groups of healthy non-obese men (n=10 per group) three types of meals with equivalent levels of palatability were tested: a liquid meal, a solid-liquid low-calorie meal, and a solid-liquid high-calorie meal. The cognitive and hedonic responses were measured on 10-cm scales before and during the 30-minute postprandial period. Key Results The liquid meal induced a relatively strong cognitive response with satiation (4.7±0.7 score increment), fullness (3.3±0.7 score increment), and inhibition of desire of eating a food of choice; in contrast, its impact on sensation of digestive well-being and satisfaction was not significant (0.7±0.7 score increment). The high-calorie solid-liquid meal, with larger volume load and caloric content, induced much lower satiation (2.4±0.8 score increment; P=.041 vs liquid meal) and fullness sensation (1.3±0.6 score increment; P=.031 vs liquid meal), but a markedly higher level of satisfaction (2.7±0.4 score increment; P=.021 vs liquid meal); the low-calorie mixed meal had less prominent effects with significantly lower satisfaction (1.0±0.4 score increment; P=.039 vs high-calorie meal). Conclusions and Inferences The cognitive (satiation, fullness) and hedonic responses (satisfaction) to meals with equivalent levels of palatability, that is, equally likable, are dissociable. The characteristics of meals in terms of satiation and rewarding power could be adapted to specific clinical targets, whether nutritional supplementation or restriction. [ABSTRACT FROM AUTHOR]

Background: Functional dyspepsia (FD) is most often a meal-induced syndrome. Studies using resting-state functional magnetic resonance imaging (rs-fMRI) reported abnormal connectivity in areas related to pain processing in FD. However, only a few studies have attempted to determine how meal ingestion affects the brain's working patterns. Through rs-fMRI, this study observed how meal ingestion affected brain regions related to visceral hypersensitivity and emotional response networks in FD patients., Methods: A total of 30 FD patients and 32 healthy controls (HC) were enrolled and underwent clinical investigations. Rs-fMRI was performed twice after a 4-h fast and 50 min after a meal. The mean functional connectivity strength (FCS) values were extracted from brain regions with significant differences to show the trend of changes related to meal ingestion after FCS analyses., Results: Depression, anxiety, sleep disturbances, and weight loss were more common in FD patients ( P ≤ 0.001). Compared with HCs (corrected cluster P -value < 0.05), FD patients had significantly higher FCS in the right middle frontal gyrus before meals and higher meal-induced FCS in the left postcentral gyrus. HCs had greater meal-induced activation in the right precuneus and anterior cingulate cortex. FD patients had a decreasing trend in the right inferior frontal gyrus compared to the increasing trend in HCs. We only found anxiety to be negatively correlated with FCS in the right inferior frontal gyrus in FD ( r = -0.459, p = 0.048, uncorrected)., Conclusions: In this study, we discovered that FD patients have different perceptual and emotional responses to food intake in defined brain areas, providing promising impetus for understanding pathogenic brain mechanisms in FD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Chen, Yu, DeSouza, Shen, Zhang, Zhu, Huang and Wang.)

Background We have previously shown that meal ingestion induces cognitive perception (sensations) with a hedonic dimension (well-being) that depends on the characteristics of the meal and the appropriateness of the digestive response. The aim of the present study is to identify metabolomic biomarkers of the cognitive response to meal ingestion. Methods In 18 healthy subjects, the response to a test meal (Edanec, 1 kcal/mL) ingested until maximum satiation (50 mL/min) was assessed. Perception measurements and blood samples were taken before, at the end of the meal, and 20 min after ingestion. The cognitive response and the hedonic dimension were measured on 10 cm scales. Metabolomic analysis was performed using nuclear magnetic resonance (NMR) spectroscopy and values of triglycerides, insulin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1) were determined using conventional laboratory techniques. Key Results Ingestion up to maximum satiation induced sensation of fullness and decreased digestive well-being. The total amount ingested by each subject correlated with the basal sensation of hunger, but not with other sensations or blood metabolite levels. Immediately after ingestion, satiation correlated with an increase in glucose ( R = 0.49; p = 0.038) and valine levels ( R = 0.48; p = 0.043). Twenty-minutes after finalizing ingestion, triglyceride levels had significantly increased which correlated with the recovery in well-being ( R = 0.48; p = 0.046) and the decrease in desire to eat a food of choice ( R = −0.56; p = 0.016). The increase in lipids inversely correlated with abdominal discomfort ( R = −0.51; p = 0.032). Conclusions & Inferences Cognitive and hedonic responses to meal ingestion correlate with changes in circulating metabolites, which may serve as objective biomarkers of perception. [ABSTRACT FROM AUTHOR]

Background Gut dysfunctions may be associated to digestive symptoms. We hypothesized that the gut can also originate pleasant sensations, and wished to demonstrate the hedonic component of the digestive response to a meal. Methods Healthy subjects ( n = 42) were evaluated during basal fasting conditions and during experimentally induced fullness sensation (either by gastric distension or duodenal nutrient infusion). In each set of studies, a 240 mL test meal (12 kcal broth) and water, as inert control meal, were administered on separate days in a randomized, cross-over design. Gastric accommodation, the cognitive response and the hedonic dimension (both by 10 score scales) were measured 9 min before and 60 min after the meal. Key Results In basal conditions, the test meal induced a significantly greater gastric relaxation than the control meal (166 ± 28 mL isotonic volume increase 67 ± 14 mL; p = 0.002). Both meals induced epigastric fullness (3.8 ± 0.7 score and 3.2 ± 0.8 score, respectively; p = 0.740), but contrary to the inert meal, with the active meal this conscious sensation had a pleasant dimension (digestive comfort increase by 1.3 ± 0.6 score with active meal vs −1.1 ± 0.6 decrease with inert meal; p = 0.015). Experimentally induced fullness was associated to a decrease in digestive well-being or abdominal discomfort, which improved only after the active meal but not the inert meal. Conclusions & Inferences When appropriate conditions are met, the response to a meal includes a hedonic dimension involving pleasant sensation of digestive well-being. [ABSTRACT FROM AUTHOR]

Background Patients with irritable bowel syndrome ( IBS) complain of postprandial abdominal pain, but it is still unknown how much of this association is due to chance. Somatization enhances the perception of symptoms after a meal. We assessed: (i) the proportion of meal-related pain periods and the symptom-association probability ( SAP) between the two variables in IBS patients; and (ii) how this association is affected by somatization. Methods Seventy IBS patients recorded the times of meals and abdominal pain in a 10-day diary card. The proportion of postmeal pain periods was calculated in relation to the total number of 90-min periods with pain. Fisher's exact test was used to calculate the probability ( p) of an association within a time window of 90 min, and the SAP was calculated as (1 − p) × 100%. The IBS Symptom Severity Scale, the SCL90-R for psychological symptoms, and the SF-36 for the quality of life were completed. Key Results The proportion of postmeal pain periods was 42 ± 27%. SAP was significant ( p < 0.05) in 32 patients (45%). Somatization was altered in 30 patients (47%), who were younger and had more severe IBS and a poorer quality of life. Somatization did not influence the association between meal ingestion and abdominal pain. Conclusions & Inferences Meal ingestion and abdominal pain are significantly associated in 45% of IBS patients. Somatization influences IBS severity and the patients' quality of life, but not the strength of the association between eating and pain. [ABSTRACT FROM AUTHOR]

Objective To investigate the role of the sympathetic nervous system in the cardiovascular response to quiet standing in the postprandial state. Method Following a 30 min pre-ingestion phase, 14 healthy young male subjects consumed a 600 kcal carbohydrate-rich meal. Arterial blood pressure (BP) and heart rate (HR) were recorded for a further 120 min. Measurements were obtained (Finometer) in both the supine (5 min) and standing (5 min) condition every 30 min. Power spectral analysis of RR-interval and BP variability was calculated, and heart rate responses to the baroreceptor reflex were calculated to estimate spontaneous baroreflex sensitivity (sBRS). Derived stroke volume (SV) was measured to track changes to postural stress postprandially. Results Quiet standing increased RR-interval low frequency power, ratio of RR-interval low frequency power/high frequency power (ratio of RR LF/HF), and systolic BP low frequency power (SBP LF power), and decreased RR HF power and sBRS before, and after eating. After meal ingestion, SBP LF power increased and sBRS decreased in lying and standing conditions. During quiet standing postprandially, DBP and the mean arterial pressure increased ( P < 0.01). The increased BP is associated with increased SV ( P < 0.05) early postprandially, and increased SBP LF power ( P < 0.01) in the later postprandial phase. SBP LF power is inversely correlated with SV postprandially ( P < 0.001, R 2 = 0.96). Conclusion The findings suggest a sympathetic activation mediated by baroreflex resetting. Quiet standing in the postprandial state enhances sympathetic outflow to the vasculature, increasing BP. SV may be a compensatory factor stabilising BP during quiet standing early postprandially. [ABSTRACT FROM AUTHOR]

Objective: The association between caffeine intake and the risk for chronic diseases, namely type 2 diabetes, has not been consistent, and may be influenced by the timing of caffeine ingestion. The aim of this study was to investigate the acute effect of caffeine administered in different scenarios of meal ingestion on postprandial glycemic and lipidemic status, concomitant with changes in body glycogen stores. Methods: Forty overnight-fasted rats were randomly divided into five groups (meal-ingested, caffeine-administered, post-caffeine meal-ingested, co-caffeine meal-ingested, post-meal caffeine- administered), and tube-fed the appropriate intervention, then sacrificed 2 h later. Livers and gastrocnemius muscles were analyzed for glycogen content; blood samples were analyzed for glucose, insulin, triglycerides, and non-esterified fatty acid concentrations. Results: Postprandial plasma glucose concentrations were similar between groups, while significantly higher levels of insulin were witnessed following caffeine administration, irrespective of the timing of meal ingestion. Triglyceride concentrations were significantly lower in the caffeine-administered groups. Regarding glycogen status, although caffeine administration before meal ingestion reduced hepatic glycogen content, co- and post-meal caffeine administration failed to produce such an effect. Muscle glycogen content was not significantly affected by caffeine administration. Conclusions: Caffeine administration seems to decrease insulin sensitivity as indicated by the sustenance of glucose status despite the presence of high insulin levels. The lower triglyceride levels in the presence of caffeine support the theory of retarded postprandial triglyceride absorption. Caffeine seems to play a biphasic role in glucose metabolism, as indicated by its ability to variably influence hepatic glycogen status. [ABSTRACT FROM AUTHOR]

Background Using an experimental model of colonic gas infusion, we previously showed that the abdominal walls adapt to its content by an active phenomenon of abdominal accommodation. We now hypothesized that abdominal accommodation is a physiological phenomenon, and aimed to confirm that it can be induced by ingestion of a meal; a secondary aim was to determine whether the response to gut filling is region-specific. Methods In healthy subjects ( n = 24) a nutrient test meal was administered until tolerated at a rate of 50 mL min−1. Electromyographic (EMG) activity of the anterior wall (upper and lower rectus, external and internal oblique) was measured via four pairs of surface electrodes, and EMG activity of the diaphragm via intraluminal electrodes on an esophageal tube. To address the secondary aim, the response to gastric filling was compared with that induced by colonic filling (1440 mL 30 min−1 anal gas infusion; n = 8). Key Results Participants tolerated 927 ± 66 mL of meal (450-1500 mL). Meal ingestion induced progressive diaphragmatic relaxation (EMG reduction by 16 ± 2%; P < 0.01) and selective contraction of the upper abdominal wall (24 ± 2% increase in activity of the upper rectus and external oblique; P < 0.01 for both), with no significant changes in the lower rectus (4 ± 2%) or internal oblique (5 ± 3%). Colonic gas infusion induced a similar response, but with an overall contraction of the anterior wall. Conclusions & Inferences Meal ingestion induces a metered and region-specific response of the abdominal walls to accommodate the volume load. Abnormal abdominal accommodation could be involved in postprandial bloating. [ABSTRACT FROM AUTHOR]

Several studies have shown that liquid and food intake interfere with the evaluation of body composition in adults. However, since there are no reports about this interference in the elderly population, the need to fast for this evaluation may be dispensable. The objective of the present study was to assess the influence of liquid and solid food on the measurement of body composition by bioelectrical impedance analysis (BIA) and by dual energy X-ray absorptiometry (DXA). Forty-one male volunteers aged 62 to 87 years participated in the study. The subjects were submitted to evaluation of body composition by DXA and BIA under fasting conditions and 1 hour after the ingestion of breakfast (500 ml of orange juice and one 50 g bread roll with butter). There was no significant difference in the variables fat-free mass (FFM) or fat mass (FM) between the fasting condition and the evaluation performed 1 hour after the meal as measured by BIA or DXA. There was also no significant difference when the same variables were compared between methods. In the present study, the ingestion of 500 ml orange juice and of one bread roll with butter by elderly subjects did not affect the results of the parameters of body composition determined by BIA or DXA. Thus, these exams could be performed without the rigor of fasting, often poorly tolerated by the elderly. [ABSTRACT FROM AUTHOR]

Background: Bioelectrical impedance analysis (BIA) can be used for estimating body composition. Earlier studies showed that the ingestion of meals lowers bioelectrical impedance, but none studied the effect of repeated ingestion of an identical meal in narrow intervals on impedance measurements during 24 h. Objectives: The objectives were to study the effect on bioelectrical impedance of 3 identical meals and to compare the results from single-frequency BIA measurements with those from multiple-frequency BIA measurements. Design: Bioelectrical impedance was measured 18 times during 24 h in 18 healthy subjects [10 women and 8 men; ... ± SD age: 31.5 ± 11.7 y; body mass index (in kg/m²): 22.2 ± 2.7]. An identical meal was given at breakfast, lunch, and dinner. Results: Bioelectrical impedance decreased after ingestion of a standard meal (P < 0.05). The decrease in impedance lasted 2-4 h after each meal. The decrease was additive during the day, although it was more pronounced after the first meal because of the combined effect of rising from the supine position and meal ingestion. This is an important consideration when calculating body composition: percentage of body fat varied by 8.8% from the highest to the lowest measurement in women and by 9.9% from the highest to the lowest measurement in men. The bioelectrical impedance at 50 kHz was identical when measured with multiple frequencies or a single frequency. Conclusion: The ingestion of meals leads to an additive decrease in bioelectrical impedance and thus to a decrease in the calculated percentage of body fat. [ABSTRACT FROM AUTHOR]