Meal composition influences postprandial sensations independently of valence and gustation.

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.

Biogastronomy: Factors that determine the biological response to meal ingestion.

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.

Education of the postprandial experience by a sensory-cognitive intervention.

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.

Effects of meal palatability on postprandial sensations.

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.

Appetite influences the responses to meal ingestion.

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.

Brain networks associated with cognitive and hedonic responses to a meal.

BACKGROUND: 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. METHODS: 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. KEY RESULTS: Ingestion induced satiation (3.3±0.4 score increase; P<.001) and abdominal fullness (2.4±0.3 score increase; P<.001). These sensations included an affective dimension involving digestive well-being (2.8±0.3 score increase; P<.001) and positive mood (1.8±0.2 score increase; P<.001). In general, thalamo-cortical connectivity increased with meal ingestion while insular-cortical connectivity mainly decreased. Furthermore, larger meal-induced changes (increase/decrease) in specific thalamic connections were associated with smaller changes in satiety/fullness. In contrast, a larger meal-induced decrease in insular-anterior cingulate cortex connectivity was associated with increased satiety, fullness, and digestive well-being. CONCLUSIONS AND INFERENCES: Perceptual and emotional responses to food intake are related to brain connectivity in defined functional networks. Brain imaging may provide objective biomarkers of subjective effects of meal ingestion.

Relation between cognitive and hedonic responses to a meal.

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.

A fresh look at IBS-opportunities for systems medicine approaches.

NeuroGUT is a EU-funded initial training network (ITN) of 14 research projects in neurogastroenterology that have employed an equal number of early-stage researchers. Neurogut trainees have-among other activities-attended an international conference on irritable bowel syndrome (IBS) in Bologna in 2016 and were asked to critically review and evaluate the current knowledge on IBS for their respective research activities, and to state what they were missing. Most appreciated were the topics brain imaging of gut activity, the role of the gut microbiota, the pharmacology of gut functions, the IBS-IBD interrelation, the new Rome IV criteria, the role of gas, and the placebo response in functional disorders. Missed were more detailed coverage of high-resolution manometry, functional brain imaging, advanced "systems medicine" approaches and bioinformatics technology, better sub-classification of IBS patients, and the development of disease biomarkers, extended at the molecular (genetic/epigenetic, proteonomic) level. They summarize that despite excellent specialized research, there is a gap open that should be filled with systems medicine. For this, it would be necessary that medical research learns even more from the data sciences and other basic disciplines, for example, information technology and system biology, and also welcomes a change in paradigm that enhances open sharing of data, information, and resources.