RESUMEN
The most successful obesity therapeutics, glucagon-like peptide-1 receptor (GLP1R) agonists, cause aversive responses such as nausea and vomiting1,2, effects that may contribute to their efficacy. Here, we investigated the brain circuits that link satiety to aversion, and unexpectedly discovered that the neural circuits mediating these effects are functionally separable. Systematic investigation across drug-accessible GLP1R populations revealed that only hindbrain neurons are required for the efficacy of GLP1-based obesity drugs. In vivo two-photon imaging of hindbrain GLP1R neurons demonstrated that most neurons are tuned to either nutritive or aversive stimuli, but not both. Furthermore, simultaneous imaging of hindbrain subregions indicated that area postrema (AP) GLP1R neurons are broadly responsive, whereas nucleus of the solitary tract (NTS) GLP1R neurons are biased towards nutritive stimuli. Strikingly, separate manipulation of these populations demonstrated that activation of NTSGLP1R neurons triggers satiety in the absence of aversion, whereas activation of APGLP1R neurons triggers strong aversion with food intake reduction. Anatomical and behavioural analyses revealed that NTSGLP1R and APGLP1R neurons send projections to different downstream brain regions to drive satiety and aversion, respectively. Importantly, GLP1R agonists reduce food intake even when the aversion pathway is inhibited. Overall, these findings highlight NTSGLP1R neurons as a population that could be selectively targeted to promote weight loss while avoiding the adverse side effects that limit treatment adherence.
Asunto(s)
Receptor del Péptido 1 Similar al Glucagón , Neuronas , Rombencéfalo , Respuesta de Saciedad , Núcleo Solitario , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Animales , Rombencéfalo/fisiología , Rombencéfalo/metabolismo , Rombencéfalo/efectos de los fármacos , Ratones , Masculino , Núcleo Solitario/metabolismo , Núcleo Solitario/efectos de los fármacos , Núcleo Solitario/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Neuronas/efectos de los fármacos , Respuesta de Saciedad/efectos de los fármacos , Respuesta de Saciedad/fisiología , Área Postrema/metabolismo , Área Postrema/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Ingestión de Alimentos/fisiología , Saciedad/fisiología , Saciedad/efectos de los fármacos , Femenino , Ratones Endogámicos C57BL , Fármacos Antiobesidad/farmacología , Obesidad/metabolismo , Péptido 1 Similar al Glucagón/metabolismo , Vías Nerviosas/efectos de los fármacos , Reacción de Prevención/efectos de los fármacos , Reacción de Prevención/fisiologíaRESUMEN
The consumption of protein-rich foods stimulates satiety more than other macronutrient-rich foods; however, the underlying mechanisms-of-action are not well-characterized. The objective of this study was to identify the direct and indirect effects of postprandial amino acid (AA) responses on satiety. Seventeen women (mean ± SEM, age: 33 ± 1 year; BMI: 27.8 ± 0.1 kg/m2) consumed a eucaloric, plant-based diet containing two servings of lean beef/day (i.e., 7.5 oz (207 g)) for 7 days. During day 6, the participants completed a 12 h controlled-feeding, clinical testing day including repeated satiety questionnaires and blood sampling to assess pre- and postprandial plasma AAs, PYY, and GLP-1. Regression and mediation analyses were completed to assess AA predictors and hormonal mediators. Total plasma AAs explained 41.1% of the variance in perceived daily fullness (p < 0.001), 61.0% in PYY (p < 0.001), and 66.1% in GLP-1 (p < 0.001) concentrations, respectively. Several individual AAs significantly predicted fluctuations in daily fullness, PYY, and GLP-1. In completing mediation analyses, the effect of plasma leucine on daily fullness was fully mediated by circulating PYY concentrations (indirect effect = B: 0.09 [Boot 95% CI: 0.032, 0.17]) as no leucine-fullness direct effect was observed. No other mediators were identified. Although a number of circulating AAs predict satiety, leucine was found to do so through changes in PYY concentrations in middle-aged women.
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Aminoácidos , Sobrepeso , Péptido YY , Periodo Posprandial , Carne Roja , Saciedad , Humanos , Femenino , Adulto , Aminoácidos/sangre , Péptido YY/sangre , Saciedad/efectos de los fármacos , Sobrepeso/sangre , Péptido 1 Similar al Glucagón/sangre , Biomarcadores/sangre , Comidas , Animales , Bovinos , Respuesta de Saciedad/efectos de los fármacosRESUMEN
Fat and its hydrolysis products, fatty acids, are indispensable nutritional components; however, prolonged excessive fat consumption, particularly in western diets, contributes to the onset of obesity and multiple metabolic disorders. In this study, we propose a daily-ingestible hydrogel (denoted as ßC-MA hydrogel) composed of natural ß-glucan and sodium carboxymethylcellulose crosslinked by malic acid at 120 °C. This hydrogel exhibits rapid swelling performance, up to 24-fold within 1 min and 176-fold after 1 h in deionized water. It also lengthens gastric retention and increases endogenous satiety signal levels, potentially controlling appetite and reducing food intake. Furthermore, ßC-MA hydrogels that enter the small intestine can effectively inhibit fat hydrolysis and decrease triglyceride synthesis and transport. Specifically, the hydrogels inhibit the release of free fatty acids (FFAs) by approximately 50 % during digestion, influence the translocation of triglycerides and FFAs across the intestinal epithelium, and reduce the serum triglyceride levels by 22.2 %. These findings suggest that ßC-MA hydrogels could serve as a noninvasive gastrointestinal device for weight control, with the advantage of reducing food intake and restoring lipid metabolism homeostasis.
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Hidrogeles , beta-Glucanos , Hidrogeles/química , beta-Glucanos/química , beta-Glucanos/farmacología , Hidrólisis , Animales , Triglicéridos/metabolismo , Masculino , Ratones , Metabolismo de los Lípidos/efectos de los fármacos , Ácidos Grasos no Esterificados/metabolismo , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/efectos de los fármacos , Respuesta de Saciedad/efectos de los fármacos , RatasRESUMEN
The suppressive effect of insulin on food intake has been documented for decades. However, whether insulin signals can encode a certain type of nutrients to regulate nutrient-specific feeding behavior remains elusive. Here, we show that in female Drosophila, a pair of dopaminergic neurons, tritocerebrum 1-dopaminergic neurons (T1-DANs), are directly activated by a protein-intake-induced insulin signal from insulin-producing cells (IPCs). Intriguingly, opto-activating IPCs elicits feeding inhibition for both protein and sugar, while silencing T1-DANs blocks this inhibition only for protein food. Elevating insulin signaling in T1-DANs or opto-activating these neurons is sufficient to mimic protein satiety. Furthermore, this signal is conveyed to local neurons of the protocerebral bridge (PB-LNs) and specifically suppresses protein intake. Therefore, our findings reveal that a brain-derived insulin signal encodes protein satiety and suppresses feeding behavior in a nutrient-specific manner, shedding light on the functional specificity of brain insulin signals in regulating behaviors.
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Proteínas de Drosophila , Insulina , Transducción de Señal , Animales , Femenino , Encéfalo/metabolismo , Neuronas Dopaminérgicas/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Conducta Alimentaria , Insulina/metabolismo , Nutrientes/metabolismo , Respuesta de SaciedadRESUMEN
Dietary protein modulates food intake (FI) via unclear mechanism(s). One possibility is that higher protein leads to greater post-ingestive heat production (Specific dynamic action: SDA) leading to earlier meal termination (increased satiation), and inhibition of further intake (increased satiety). The influence of dietary protein on feeding behaviour in C57BL/6J mice was tested using an automated FI monitoring system (BioDAQ), simultaneous to body temperature (Tb). Total FI, inter meal intervals (IMI, satiety) and meal size (MS, satiation) were related to changes in Tb after consuming low (5%, LP), moderate (15%, MP) and high (30%, HP) protein diets. Diets were tested over three conditions: 1) room temperature (RT, 21 ± 1 °C), 2) room temperature and running wheels (RTRW) and 3) low temperature (10 °C) and running wheels (LTRW). The differences between diets and conditions were also compared using mixed models. Mice housed at RT fed HP diet, reduced total FI compared with LP and MP due to earlier meal termination (satiation effect). FI was lowered in RTRW conditions with no differences between diets. FI significantly increased under LTRW conditions for all diets, with protein content leading to earlier meal termination (satiation) but not the intervals between feeding bouts (satiety). Tb fell immediately after feeding in all conditions. Despite a reduction in total FI in mice fed HP, mediated via increased satiation, this effect was not linked to increased Tb during meals. We conclude effects of dietary protein on intake are not mediated via SDA and Tb.
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Temperatura Corporal , Proteínas en la Dieta , Ratones Endogámicos C57BL , Saciedad , Animales , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/farmacología , Masculino , Ratones , Conducta Alimentaria/fisiología , Ingestión de Alimentos/fisiología , Respuesta de SaciedadRESUMEN
Hunger and satiety can have an influence on decision-making, sensory processing, and motor behavior by altering the internal state of the brain. This process necessitates the integration of peripheral sensory stimuli into the central nervous system. Here, we show how animals without a central nervous system such as the cnidarian Hydra measure and integrate satiety into neuronal circuits and which specific neuronal populations are involved. We demonstrate that this simple nervous system, previously referred to as diffuse, has an endodermal subpopulation (N4) similar to the enteric nervous system (feeding-associated behavior) and an ectodermal population (N3) that performs central nervous system-like functions (physiology/motor). This view of a supposedly simple nervous system could open an important window into the origin of more complex nervous systems.
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Sistema Nervioso Central , Sistema Nervioso Entérico , Hydra , Neuronas , Animales , Hydra/fisiología , Neuronas/fisiología , Sistema Nervioso Entérico/fisiología , Sistema Nervioso Central/fisiología , Conducta Animal/fisiología , Respuesta de Saciedad/fisiologíaRESUMEN
Extensive research is undertaken in rodents to determine the mechanism underlying obesity-induced leptin resistance. While body weight is generally tightly controlled in these studies, the effect of age of experimental animals has received less attention. Specifically, there has been little investigation into leptin regulation of food intake in middle-aged animals, which is a period of particular relevance for weight gain in humans. We investigated whether the satiety effects of leptin remained constant in young (3 months), middle-aged (12 months) or aged (18-22 months) male mice. Although mean body weight increased with age, leptin concentrations did not significantly increase in male mice beyond 12 months of age. Exogenous leptin administration led to a significant reduction in food intake in young mice but had no effect on food intake in middle-aged male mice. This loss of the satiety effect of leptin appeared to be transient, with leptin administration leading to the greatest inhibition of food intake in the aged male mice. Subsequently, we investigated whether these differences were due to changes in leptin transport into the brain with ageing. No change in leptin clearance from the blood or transport into the brain was observed, suggesting the emergence of central resistance to leptin in middle age. These studies demonstrate the presence of dynamic and age-specific changes in the satiety effects of leptin in male mice and highlight the requirement for age to be carefully considered when undertaking metabolic studies in rodents.
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Envejecimiento , Ingestión de Alimentos , Leptina , Ratones Endogámicos C57BL , Respuesta de Saciedad , Animales , Leptina/farmacología , Masculino , Ratones , Ingestión de Alimentos/efectos de los fármacos , Ingestión de Alimentos/fisiología , Envejecimiento/fisiología , Envejecimiento/metabolismo , Respuesta de Saciedad/efectos de los fármacos , Respuesta de Saciedad/fisiología , Peso Corporal/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/efectos de los fármacosRESUMEN
Remedies for the treatment of obesity date to Hippocrates, when patients with obesity were directed to "reduce food and avoid drinking to fullness" and begin "running during the night." Similar recommendations have been repeated ever since, despite the fact that they are largely ineffective. Recently, highly effective therapeutics were developed that may soon enable physicians to manage body weight in patients with obesity in a manner similar to the way that blood pressure is controlled in patients with hypertension. These medicines have grown out of a revolution in our understanding of the molecular and neural control of appetite and body weight, reviewed here.
Asunto(s)
Obesidad , Respuesta de Saciedad , Humanos , Respuesta de Saciedad/fisiología , Apetito/fisiología , Peso CorporalRESUMEN
BACKGROUND: Intestinal nutrient sensing regulates food intake and energy metabolism by acting locally and relaying nutritional status to the brain. It is unclear whether these mechanisms are altered in obese humans. OBJECTIVES: We aimed to investigate differences in duodenal nutrient sensing in humans with or without obesity and the effects of transiently blocking vagal transmission on nutrient sensing, hunger, and appetite. METHODS: In a single-blinded, randomized, cross-over design, subjects with or without obesity (n = 14 and n = 11, respectively) were infused intraduodenally with saline or a combination of glucose and oleic acid for 90 min (glucose load: 22.5 g, 1 kcal/min; oleic acid load: 10 g, 1 kcal/min) in the presence or absence of local anesthetic (benzocaine). Blood was sampled at 10-min intervals (120-240 min) and 15-min intervals until termination of the study for measurements of gut hormones, insulin, leptin, and C-peptide. Hunger and satiety sensations were scored using the visual analog scale, and hepatic glucose production and glucose oxidation rates were measured. RESULTS: Duodenal nutrient infusion in lean subjects led to a 65% drop in acyl ghrelin release and robustly increased cholecystokinin 8 (CCK-8) release (65%; P = 0.023); benzocaine infusion delayed this response (2-factor repeated-measures analysis of variance, P = 0.0065). In contrast, subjects with obesity had significantly blunted response to nutrient infusion, and no further effects were observed with benzocaine. Additionally, significant delays were observed in peptide YY (3-36), pancreatic polypeptide, glucose inhibitory peptide, and glucagon-like peptide 1 (7-36) response. No significant interactions were found between body mass index (BMI) or baseline hormone levels and areas under the curve for hormones except CCK-8 (BMI, P = 0.018; baseline CCK, P = 0.013). Nutrient-induced hunger and satiety sensations were impeded by benzocaine only in the lean cohort. Hunger and satiety sensations in subjects with obesity were not responsive to nutrient entry into the duodenum, and no additional effects were observed by blocking neural signaling. CONCLUSION: Nutrient-induced gut hormone release and response to transient vagal blockade are significantly blunted in subjects with obesity. This trial was registered at clinicaltrials.org as NCT02537314.
Asunto(s)
Apetito , Obesidad , Respuesta de Saciedad , Delgadez , Humanos , Masculino , Femenino , Adulto , Nutrientes/administración & dosificación , Duodeno , Obesidad/terapia , Delgadez/terapiaRESUMEN
Postprandial glycaemic response amplitude plays a critical role in diabetic complications, but is subject to food order and temporal separation within a meal. Effects of partial fruit-for-cereal carbohydrate exchange on glycaemic and appetite responses, as affected by food order and separation, were examined using kiwifruit (KF) and wheaten breakfast cereal biscuit (WB). In a randomized cross-over intervention study, 20 subjects ingested 51.7 g of available carbohydrate as 74 g WB alone, or as 200 g KF and 37 g WB, each delivering 25.85 g of available carbohydrate. The 200 g KF was partially exchanged for 37 g of WB, at 90 min and 30 min before, at the same time as, or 30 min after, ingesting WB. Incremental satiety responses were derived from appetite scores measured using a visual analogue scale, and capillary blood glucose responses were monitored. In all exchanges, KF reduced the glycaemic response (iAUC) by 20-30% with no loss of total satiation. The incremental glycaemic and satiety responses to food ingestion followed each other closely. Glycaemic response amplitudes were reduced almost 50% compared with 74 g WB when KF ingestion preceded WB ingestion by 30 min, and less when the KF was ingested with or 30 min after the cereal. The results suggest that fruit most effectively suppresses the digestion of cereal carbohydrates if ingested long enough before the cereal to prevent overlap of the glycaemic responses, but close enough for fruit components that impede carbohydrate digestion or uptake to interact with the ingested cereal in the gut. Ethics approval was obtained from the Human and Disabilities Ethics Committee (HDEC) of the New Zealand Ministry of Health. The trial was registered with the Australian New Zealand Clinical Trials Registry (Trial ID: ACTRN12615000744550).
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Grano Comestible , Frutas , Humanos , Glucemia , Respuesta de Saciedad , Australia , Carbohidratos de la Dieta/farmacología , Estudios Cruzados , Periodo Posprandial , InsulinaRESUMEN
A relatively new pharmacological target in obesity treatment has been the preproglucagon (PPG) signalling, predominantly with glucagon-like peptide (GLP) 1 receptor agonists. As far as the PPG role within the digestive system is well recognised, its actions in the brain remain understudied. Here, we investigated PPG signalling in the Dorsomedial Hypothalamus (DMH), a structure involved in feeding regulation and metabolism, using in situ hybridisation, electrophysiology, and immunohistochemistry. Our experiments were performed on animals fed both control, and high-fat diet (HFD), uncovering HFD-mediated alterations. First, sensitivity to exendin-4 (Exn4, a GLP1R agonist) was shown to increase under HFD, with a higher number of responsive neurons. The amplitude of the response to both Exn4 and oxyntomodulin (Oxm) was also altered, diminishing its relationship with the cells' spontaneous firing rate. Not only neuronal sensitivity, but also GLP1 presence, and therefore possibly release, was influenced by HFD. Immunofluorescent labelling of the GLP1 showed changes in its density depending on the metabolic state (fasted/fed), but this effect was eliminated by HFD feeding. Interestingly, these dietary differences were absent after a period of restricted feeding, allowing for an anticipation of the alternating metabolic states, which suggests possible prevention of such outcome.
Asunto(s)
Dieta Alta en Grasa , Hipotálamo , Proglucagón , Transducción de Señal , Animales , Ratas , Hipotálamo/fisiología , Proglucagón/metabolismo , Ratas Sprague-Dawley , Masculino , Receptor del Péptido 1 Similar al Glucagón/genética , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Receptor del Péptido 2 Similar al Glucagón/genética , Receptor del Péptido 2 Similar al Glucagón/metabolismo , ARN Mensajero/metabolismo , Neuronas/metabolismo , Sinapsis , Fibras Nerviosas/metabolismo , Electrofisiología , Proteínas Proto-Oncogénicas c-fos/metabolismo , Respuesta de Saciedad , Conducta AlimentariaRESUMEN
The transcripts for Bdnf (brain-derived neurotrophic factor), driven by different promoters, are expressed in different brain regions to control different body functions. Specific promoter(s) that regulates energy balance remain unclear. We show that disruption of Bdnf promoters I and II but not IV and VI in mice (Bdnf-e1-/-, Bdnf-e2-/-) results in obesity. Whereas Bdnf-e1-/- exhibited impaired thermogenesis, Bdnf-e2-/- showed hyperphagia and reduced satiety before the onset of obesity. The Bdnf-e2 transcripts were primarily expressed in ventromedial hypothalamus (VMH), a nucleus known to regulate satiety. Re-expressing Bdnf-e2 transcript in VMH or chemogenetic activation of VMH neurons rescued the hyperphagia and obesity of Bdnf-e2-/- mice. Deletion of BDNF receptor TrkB in VMH neurons in wildtype mice resulted in hyperphagia and obesity, and infusion of TrkB agonistic antibody into VMH of Bdnf-e2-/- mice alleviated these phenotypes. Thus, Bdnf-e2-transcripts in VMH neurons play a key role in regulating energy intake and satiety through TrkB pathway.
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Factor Neurotrófico Derivado del Encéfalo , Receptor trkB , Respuesta de Saciedad , Animales , Ratones , Factor Neurotrófico Derivado del Encéfalo/genética , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Hiperfagia/genética , Hiperfagia/metabolismo , Hipotálamo/metabolismo , Neuronas/metabolismo , Obesidad/genética , Obesidad/metabolismo , Receptor trkB/genética , Receptor trkB/metabolismoRESUMEN
Overconsumption of sugar contributes to obesity in part by changing the activity of brain areas that drive the motivation to seek out and consume food. Sugar-sweetened beverages are the most common source of excess dietary sugar and contribute to weight gain. However, very few studies have assessed the effects of liquid sucrose consumption on motivation. This is due in part to the need for novel approaches to assess motivation in pre-clinical models. To address this, we developed a within-session behavioral economics procedure to assess motivation for liquid sucrose. We first established and validated the procedure: we tested several sucrose concentrations, evaluated sensitivity of the procedure to satiety, and optimized several testing parameters. We then applied this new procedure to determine how intermittent vs. continuous access to liquid sucrose (1 M) in the home cage affects sucrose motivation. We found that intermittent liquid sucrose access results in an escalation of sucrose intake in the home cage, without altering motivation for liquid sucrose during demand testing (1 M or 0.25 M) compared to water-maintained controls. In contrast, continuous home cage access selectively blunted motivation for 1 M sucrose, while motivation for 0.25 M sucrose was similar to intermittent sucrose and control groups. Thus, effects of continuous home cage liquid sucrose access were selective to the familiar sucrose concentration. Finally, effects of sucrose on motivation recovered after removal of liquid sucrose from the diet. These data provide a new approach to examine motivation for liquid sucrose and show that escalation of intake and motivation for sucrose are dissociable processes.
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Sacarosa en la Dieta , Economía del Comportamiento , Motivación , Motivación/efectos de los fármacos , Sacarosa en la Dieta/administración & dosificación , Sacarosa en la Dieta/química , Sacarosa en la Dieta/farmacología , Ratas Sprague-Dawley , Masculino , Animales , Ratas , Reproducibilidad de los Resultados , Respuesta de Saciedad/efectos de los fármacos , Vivienda para Animales , HambreRESUMEN
PURPOSE: Secretin activates brown adipose tissue (BAT) and induces satiation in both mice and humans. However, the exact brain mechanism of this satiety inducing, secretin-mediated gut-BAT-brain axis is largely unknown. METHODS AND RESULTS: In this placebo-controlled, single-blinded neuroimaging study, firstly using [18F]-fluorodeoxyglucose (FDG) PET measures (n = 15), we established that secretin modulated brain glucose consumption through the BAT-brain axis. Predominantly, we found that BAT and caudate glucose uptake levels were negatively correlated (r = -0.54, p = 0.037) during secretin but not placebo condition. Then, using functional magnetic resonance imaging (fMRI; n = 14), we found that secretin improved inhibitory control and downregulated the brain response to appetizing food images. Finally, in a PET-fMRI fusion analysis (n = 10), we disclosed the patterned correspondence between caudate glucose uptake and neuroactivity to reward and inhibition, showing that the secretin-induced neurometabolic coupling patterns promoted satiation. CONCLUSION: These findings suggest that secretin may modulate the BAT-brain metabolic crosstalk and subsequently the neurometabolic coupling to induce satiation. The study advances our understanding of the secretin signaling in motivated eating behavior and highlights the potential role of secretin in treating eating disorders and obesity. TRIAL REGISTRATION: EudraCT no. 2016-002373-35, registered 2 June 2016; Clinical Trials no. NCT03290846, registered 25 September 2017.
Asunto(s)
Tejido Adiposo Pardo , Apetito , Eje Cerebro-Intestino , Encéfalo , Conducta Alimentaria , Neuroimagen Funcional , Respuesta de Saciedad , Secretina , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Pardo/fisiología , Apetito/efectos de los fármacos , Apetito/fisiología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/fisiología , Secretina/metabolismo , Secretina/farmacología , Respuesta de Saciedad/efectos de los fármacos , Respuesta de Saciedad/fisiología , Eje Cerebro-Intestino/efectos de los fármacos , Eje Cerebro-Intestino/fisiología , Método Simple Ciego , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Glucosa/metabolismo , Recompensa , Transducción de Señal/efectos de los fármacos , Humanos , Conducta Alimentaria/efectos de los fármacos , AlimentosRESUMEN
While obesity remains a pressing issue, the wider population continues to be exposed to more digital food content than ever before. Much research has demonstrated the priming effect of visual food content, i.e., exposure to food cues increasing appetite and food intake. In contrast, some recent research points out that repeated imagined consumption can facilitate satiate and decrease food intake. Such findings have been suggested as potential remedies to excessive food cue exposure. However, the practically limitless variety of digital food content available today may undermine satiation attempts. The present work aims to replicate and extend prior findings by introducing a within-subjects baseline comparison, disentangling general and (sensory-) specific eating desires, as well as considering the moderating influence of visual and flavour stimulus variety. Three online studies (n = 1149 total) manipulated food colour and flavour variety and reproducibly revealed a non-linear dose-response pattern of imagined eating: 3 repetitions primed, while 30 repetitions satiated. Priming appeared to be specific to the taste of the exposed stimulus, and satiation, contrary to prior literature, appeared to be more general. Neither colour nor flavour variety reliably moderated any of the responses. Therefore, the results suggest that a more pronounced variety may be required to alter imagery-induced satiation.
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Ingestión de Alimentos , Saciedad , Humanos , Ingestión de Alimentos/fisiología , Saciedad/fisiología , Apetito/fisiología , Alimentos , Preferencias Alimentarias/fisiología , Gusto/fisiología , Aromatizantes , Respuesta de Saciedad , Ingestión de EnergíaRESUMEN
Studies suggest that the type of dietary fat consumed habitually may modulate appetite and further influence weight management. The purpose of this study was to evaluate the impact of an 8-week diet intervention enriched with either cottonseed oil (CSO; polyunsaturated fat-rich) or olive oil (OO; monounsaturated fat-rich) on appetite responses in adults with high cholesterol. This was a parallel design, randomized partial outpatient feeding trial designed to provide approximately 60% of participants daily energy needs with â¼30% of energy needs as CSO (n = 21, BMI 27.3 ± 0.92 kg/m2, age 53 ± 2y) or OO (n = 21, BMI 27.6 ± 1.20 kg/m2, age 54 ± 2y). A high saturated fat meal challenge was completed at pre- and post-intervention visits with 5 h postprandial blood draws and visual analog scales (VAS) for cholecystokinin (CCK), peptide YY (PYY), ghrelin, and subjective appetite, respectively. Participants also completed VAS questionnaires hourly and recorded dietary intake after leaving the lab for the remainder of the day. There was a greater increase in fasting CCK (CSO: 0.54 ± 0.03 to 0.56 ± 0.04; OO: 0.63 ± 0.07 to 0.60 ± 0.06 ng/ml p = 0.05), a greater suppression of postprandial ghrelin (p < 0.01), and a greater increase in postprandial VAS fullness (p = 0.04) in CSO compared to OO. Additionally, there was a greater decrease in self-reported energy intake in CSO compared to OO (CSO: 2464 ± 123 to 2115 ± 123; OO: 2263 ± 147 to 2,434 ± 184 kcal/d p = 0.02). Only postprandial VAS prospective consumption showed greater suppression (p = 0.03) in OO vs. CSO. Altogether, these data show that CSO has a greater effect on appetite suppression than OO diet enrichment and may be beneficial for weight maintenance, especially in a population at-risk for chronic disease. Registered at clinicaltrials.gov: NCT04397055.
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Hambre , Respuesta de Saciedad , Adulto , Humanos , Persona de Mediana Edad , Aceite de Oliva/farmacología , Aceite de Semillas de Algodón , Ghrelina , Estudios Prospectivos , Dieta , Colecistoquinina , Periodo Posprandial , Péptido YYRESUMEN
Organisms use several strategies to mitigate mitochondrial stress, including the activation of the mitochondrial unfolded protein response (UPRmt). The UPRmt in Caenorhabditis elegans, regulated by the transcription factor ATFS-1, expands on this recovery program by inducing an antimicrobial response against pathogens that target mitochondrial function. Here, we show that the mammalian ortholog of ATFS-1, ATF5, protects the host during infection with enteric pathogens but, unexpectedly, by maintaining the integrity of the intestinal barrier. Intriguingly, ATF5 supports intestinal barrier function by promoting a satiety response that prevents obesity and associated hyperglycemia. This consequently averts dysregulated glucose metabolism that is detrimental to barrier function. Mechanistically, we show that intestinal ATF5 stimulates the satiety response by transcriptionally regulating the gastrointestinal peptide hormone cholecystokinin, which promotes the secretion of the hormone leptin. We propose that ATF5 protects the host from enteric pathogens by promoting intestinal barrier function through a satiety-response-mediated metabolic control mechanism.
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Proteínas de Caenorhabditis elegans , Animales , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Respuesta de Saciedad , Caenorhabditis elegans/metabolismo , Mitocondrias/metabolismo , Respuesta de Proteína Desplegada , Mamíferos/metabolismoRESUMEN
We compared the effects of consuming egg-breakfast of superior protein quality to cereal-breakfast of similar energy density and protein quantity, but lower protein quality. Two, two-week randomised crossover clinical trials included 30 otherwise healthy women with overweight or obesity. Subjects received counselling to follow a reduced-calorie diet. Under supervision, participants consumed either breakfast for one-week then crossed over to the opposite breakfast. Experiment-1 outcome variables included post-breakfast appetite hormones, glucose and insulin, subjective markers of satiety and energy intake at lunch and dinner. In Experiment-2, an appealing food (brownies) was included in lunch. Following the breakfasts, Experiment-1 showed no significant differences in outcome variables. In Experiment-2, the egg-breakfast increased fullness (p = 0.038), but lunch-time energy intake was not different. If these findings apply to other breakfasts, it suggests that in comparing two breakfasts with similar protein quantity, the greater protein quality of a breakfast may not be adequate to induce satiety.
Asunto(s)
Desayuno , Grano Comestible , Femenino , Humanos , Apetito , Estudios Cruzados , Saciedad , Respuesta de Saciedad , Pérdida de PesoRESUMEN
CONTEXT: Obesity interventions often result in increased motivation to eat. OBJECTIVE: We investigated relationships between obesity outcomes and changes in brain activation by visual food cues and hormone levels in response to obesity intervention by family-based behavioral treatment (FBT). METHODS: Neuroimaging and hormone assessments were conducted before and after 24-week FBT intervention in children with obesity (OB, nâ =â 28), or children of healthy weight without intervention (HW, nâ =â 17), all 9- to 11-year-old boys and girls. We evaluated meal-induced changes in neural activation to high- vs low-calorie food cues across appetite-processing brain regions and gut hormones. RESULTS: Among children with OB who underwent FBT, greater declines of BMI z-score were associated with lesser reductions after the FBT intervention in meal-induced changes in neural activation to high- vs low-calorie food cues across appetite-processing brain regions (Pâ <â 0.05), and the slope of relationship was significantly different compared with children of HW. In children with OB, less reduction in brain responses to a meal from before to after FBT was associated with greater meal-induced reduction in ghrelin and increased meal-induced stimulation in peptide YY and glucagon-like peptide-1 (all Pâ <â 0.05). CONCLUSION: In response to FBT, adaptations of central satiety responses and peripheral satiety-regulating hormones were noted. After weight loss, changes of peripheral hormone secretion support weight loss, but there was a weaker central satiety response. The findings suggest that even when peripheral satiety responses by gut hormones are intact, the central regulation of satiety is disturbed in children with OB who significantly improve their weight status during FBT, which could favor future weight regain.