Caractérisation des phénomènes de convergence des choix alimentaires en contexte collectif au moyen de graphes étiquetés : exemple des choix de plats en restauration collective universitaire

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Peripherally injected cholecystokinin-induced neuronal activation is modified by dietary composition in mice

The aim of this study was to investigate the effect of long-term nutrient intake on the central response to the anorexigenic gut hormone CCK. C57BL/6 mice were fed one of three diets for 6 weeks: standard high carbohydrate (HC), high fat (HF), or high protein (HP). Assessment of brain response to cholecystokinin (CCK) by manganese-enhanced MRI (MEMRI) showed a reduction in neuronal activity both in an appetite-related area (ventromedial nucleus of the hypothalamus) and areas associated with reward (nucleus accumbens and striatum) regardless of diet. When comparing diet effects, while the HF diet did not induce any change in activity, reductions in MEMRI-associated signal were found in the paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) when comparing the HP to the HC diet. In addition, a significant interaction was found between CCK administration and the HF diet, shown by an increased activation in the PVN, which suggests a decrease the inhibiting action of CCK. Our results put forward that the long-term intake of an HP diet leads to a reduction in basal hypothalamic activation while a high-fat diet leads to desensitization to CCK-induced effects in the hypothalamus

Protein status modulates the activity of reward system in response to protein intake

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Iron-Catalysed Reductive Amination of Carbonyl Derivatives with ω-Amino Fatty Acids to Access Cyclic Amines

International audienceAn efficient method for the reductive amination of carbonyl derivatives with ω-amino fatty acids catalysed by an iron complex Fe(CO) (IMes) [IMes=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene] by means of hydrosilylation was developed. A variety of pyrrolidines, piperidines and azepanes were selectively synthesised in moderate-to-excellent yields (36 examples, 47-97 % isolated yield) with a good functional group tolerance

Effect of chronic variable stress on central regulation of food intake and neurogenesis

Chronic stress alters several central mechanisms including those of food intake regulation and neurogenesis. Our goal was to deter-mine the effect of chronic variable stress (CVS) on these two systems. Two experiments were performed using 2 weeks CVS in male Wistar rats. CVS consisted of daily unpredictable exposure to a variety of stressors. In the first experiment, food intake and body weight were measured daily. At the end of CVS, hypothalamic neuropeptide mRNA expression, basal plasma hormone levels and body composition were measured. In the second experiment, the effects of CVS on brain morphology were assessed by MRI, and at the cellular level by staining. Rats exposed to CVS displayed greater corticotropin releasing factor (CRF) and a tendency towards lower neuropeptide Y (NPY) expression, plus a decreased body weight due to diminution of adipose tissue mass compared to control rats. A decrease in food intake only partly explained this decrease since stressed rats also showed a reduced weight gain per kJ ingested. Stressed rats had a 2-fold increase in basal corticosterone levels. The effects of CVS on neuroanatomy of the brain are currently being analysed. In conclusion, CVS affected central food intake regulation. CVS induced a decrease in food intake, probably due to CRF inhibition of orexigenic NPY neurons. The lowered body weight of stressed rats could be explained by an inhibition of food intake and, since CVS only lasted 2 weeks, an acute lipolytic effect of corticosterone

Nutritional labeling modifies meal composition strategies in a computer-based food selection task

International audienceNutritional information via simplified labelling on products’ front of pack has become common in retail stores and is now concerning collective catering. While numerous studies have investigated the effects of such information policies on consumers' decisions in shops, few studies have focused on choices made in collective catering. In such settings, consumers must compose a meal by combining dishes to be eaten during the same occasion. Each choice is then dependent of the selection of other foods, yielding a different decision problem as in a store where items are selected independently of one another. The aim of this study was to understand whether a nutritional labelling, (Nutri-Score®), modified the choices of consumers and more precisely modified the meal composition strategies - the associations between dishes made by consumers. A computerized menu composition task was designed, 371 participants were randomly redirected either to an interface displaying the Nutri-Score® of dishes, or to an interface showing the dishes without Nutri-Score®. Bayesian logistic regressions were used to explore dependency relationships between foods in presence or absence of Nutri-Score®. When considering dishes individually, no significant effects of the Nutri-Score® were observed, but significant effects of the Nutri-Score® on composition strategies could be observed. Two types of strategies seemed to emerge: homogeneous behaviors, where selected dishes had similar scores and, compensatory behaviors where selected dishes had contrasted scores. In conclusion, the effect of a nutritional labelling can have complex consequences on food decisions that extend beyond the selection of food items taken individually

Une expérience unique pour provoquer deux effets d’anticipation sensorielle distincts : l’assimilation et le contraste

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O18: La texture de la nourriture affecte la satiété et les mécanismes centraux de la prise alimentaire chez l’homme : étude par IRM fonctionnelle

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L’accès à de l’eau sucrée a des conséquences délétères mais réversibles, plus marquées chez la souris prédisposée à l’obésité que chez la souris résistante

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