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• The degree of fluid satiety differentially affects taste-aversive memory formation. • H3 receptor activation in the insular cortex disrupted CTA only under fluid deprivation regimen. • RAMH in the insular cortex decreases novel appetitive response only in the ad libitum regime. • H3 receptor activation during ad libitum conditioning accelerates aversive memory extinction. Conditioned taste aversion (CTA) is a robust associative learning; liquid deprivation during this conditioning allows researchers to obtain readable measures of associative learning. Recent research suggests that thirst could be a crucial motivator that modulates conditioning and memory extinction processes, highlighting the importance of the body's internal state during learning. Furthermore, the histaminergic system is one of the major modulatory systems controlling several behavioral and neurobiological functions, such as feeding, water intake, and nociception. Therefore, this research aimed to assess the effect of H3 histaminergic receptor activation in the insular cortex (IC) during CTA. For this, we conditioned adult male Wistar rats under two regimens: water deprivation and water ad libitum. A classical CTA protocol was used for water deprivation. Before CTA acquisition, 10 μM R-α-methylhistamine (RAMH), an H3 receptor agonist, was injected into the IC. Results showed that RAMH injections decreased CTA in water-deprived rats without affecting the significant aversion conditioning in rats that were given water ad libitum. Moreover, RAMH accelerated the process of aversive memory extinction under ad libitum water conditions. According to our findings, the degree of liquid satiety differentially affected taste-aversive memory formation, and H3 histamine receptors were more involved under water deprivation conditions during acquisition. However, these receptors modulated the strength of aversive conditioning by altering the rate of aversive memory extinction in the absence of deprivation. In conclusion, histaminergic activity in the IC may influence taste memory dynamics through different mechanisms depending on the degree of liquid satiety or deprivation during conditioning. [ABSTRACT FROM AUTHOR]

Metabolic programming may be induced by reduction or enhancement of litter size, which lead to neonatal over or undernutrition, respectively. Changes in neonatal nutrition can challenge some regulatory processes in adulthood, such as the hypophagic effect of cholecystokinin (CCK). In order to investigate the effects of nutritional programming on the anorexigenic function of CCK in adulthood, pups were raised in small (SL, 3 pups per dam), normal (NL, 10 pups per dam), or large litters (LL, 16 pups per dam), and on postnatal day 60, male rats were treated with vehicle or CCK (10 µg/Kg) for the evaluation of food intake and c-Fos expression in the area postrema (AP), nucleus of solitary tract (NTS), and paraventricular (PVN), arcuate (ARC), ventromedial (VMH), and dorsomedial (DMH) nuclei of the hypothalamus. Overnourished rats showed increased body weight gain that was inversely correlated with neuronal activation of PaPo, VMH, and DMH neurons, whereas undernourished rats had lower body weight gain, inversely correlated with increased neuronal activation of PaPo only. SL rats showed no anorexigenic response and lower neuron activation in the NTS and PVN induced by CCK. LL exhibited preserved hypophagia and neuron activation in the AP, NTS, and PVN in response to CCK. CCK showed no effect in c-Fos immunoreactivity in the ARC, VMH, and DMH in any litter. These results indicate that anorexigenic actions, associated with neuron activation in the NTS and PVN, induced by CCK were impaired by neonatal overnutrition. However, these responses were not disrupted by neonatal undernutrition. Thus, data suggest that an excess or poor supply of nutrients during lactation display divergent effects on programming CCK satiation signaling in male adult rats. • Body weight is inversely correlated to neuron activity in hypothalamic nuclei. • Opposite neonatal nutrition supply has divergent effects on CCK actions in adulthood. • CCK-induced anorexigenic effect is abolished in overnourished rats. • Neonatal undernourished rats have preserved CCK satiation signaling. • SL rats have lower CCK-induced NTS and PVN neuron activation. [ABSTRACT FROM AUTHOR]

Water is critical for survival and thirst is a powerful way of ensuring that fluid levels remain in balance. Overconsumption, however, can have deleterious effects, therefore optimization requires a need to balance the drive for water with the satiation of that water drive. This review will highlight our current understanding of how thirst is both generated and quenched, with particular focus on the roles of angiotensin II, glucagon like-peptide 1, and estradiol in turning on and off the thirst drive. Our understanding of the roles these bioregulators play has benefited from modern behavioral analyses, which have improved the time resolution of intake measures, allowing for attention to the details of the patterns within a bout of intake. This has led to behavioral interpretation in ways that are helpful in understanding the many controls of water intake and has expanded our understanding beyond the dichotomy that something which increases water intake is simply a "stimulator" while something that decreases water intake is simply a "satiety" factor. Synthesizing the available information, we describe a framework in which thirst is driven directly by perturbations in fluid intake and indirectly modified by several bioregulators. This allows us to better highlight areas that are in need of additional attention to form a more comprehensive understanding of how the system transitions between states of thirst and satiety. • Thirst and water intake are under direct and indirect controls. • Stimulation of thirst is better understood than quenching thirst. • Numerous bioregulators influence thirst and water intake. • Drinking microstructure analysis helps understand how bioregulators change intake. [ABSTRACT FROM AUTHOR]

Background A possible driver of obesity is insensitivity (passive overconsumption) to food energy density (ED, kcal/g); however, it is unclear whether this insensitivity applies to all meals. Objectives We assessed the influence of ED on energy intake (kcal) across a broad and continuous range of EDs comprised of noncovertly manipulated, real-world meals. We also allowed for the possibility that the association between energy intake and ED is nonlinear. Methods We completed a secondary analysis of 1519 meals which occurred in a controlled environment as part of a study conducted by Hall and colleagues to assess the effects of food ultra-processing on energy intake. To establish the generalizability of the findings, the analyses were repeated in 32,162 meals collected from free-living humans using data from the UK National Diet and Nutrition Survey (NDNS). Segmented regressions were performed to establish ED "breakpoints" at which the association between consumed meal ED and mean centered meal caloric intake (kcal) changed. Results Significant breakpoints were found in both the Hall et al. data set (1.41 kcal/g) and the NDNS data set (1.75 and 2.94 kcal/g). Centered meal caloric intake did not increase linearly with consumed meal ED, and this pattern was captured by a 2-component ("volume" and "calorie content" [biologically derived from the sensing of fat, carbohydrate, and protein]) model of physical meal size (g), in which volume is the dominant signal with lower energy-dense foods and calorie content is the dominant signal with higher energy-dense foods. Conclusions These analyses reveal that, on some level, humans are sensitive to the energy content of meals and adjust meal size to minimize the acute aversive effects of overconsumption. Future research should consider the relative importance of volume and calorie-content signals, and how individual differences impact everyday dietary behavior and energy balance. [ABSTRACT FROM AUTHOR]

Amylin, a pancreatic hormone, is well-established to suppress feeding by enhancing satiation. Pramlintide, an amylin analog that is FDA-approved for the treatment of diabetes, has also been shown to produce hypophagia. However, the behavioral mechanisms underlying the ability of pramlintide to suppress feeding are unresolved. We hypothesized that systemic pramlintide administration in rats would reduce energy intake, specifically by reducing meal size. Male rats were given b.i.d. administration of intraperitoneal pramlintide or vehicle for 1 week, and chow intake, meal patterns, and body weight were monitored throughout the test period. Consistent with our hypothesis, pramlintide decreased chow intake mainly via suppression of meal size, with corresponding reductions in meal duration on several days. Fewer effects on meal number or feeding rate were detected. Pramlintide also reduced weight gain over the 1-week study. These results highlight that the behavioral mechanisms by which pramlintide produces hypophagia are similar to those driven by amylin itself, and provide important insight into the ability of this pharmacotherapy to promote negative energy balance over a period of chronic administration. • Systemic 2x/day injection of the amylin analog pramlintide reduces feeding in rats. • Pramlintide-induced hypophagia is driven by smaller meal size. • Pramlintide also reduced dark-phase meal duration on several days. • Fewer changes in meal number or feeding rate were observed. • Body weight gain was also suppressed by 7 consecutive days of pramlintide treatment. [ABSTRACT FROM AUTHOR]

Legumes are an important source of plant-based protein that are known to provide many beneficial health effects, but their global consumption is low. Thus, processing legumes to improve their protein digestibility and incorporating them into commonly consumed foods could be a useful strategy to increase legume consumption and obtain the nutritional benefits, including increased protein intake and enhanced satiety. This review highlights various food processing techniques that can be utilised to enhance the digestibility of legume protein, particularly when used to enrich food products. Whether such a strategy benefits metabolic health, satiety perception, and postprandial hormone responses to such foods is then evaluated. Finally, consumer acceptance of legume-based food products is examined. Food processing techniques can be used to enhance the digestibility of legume protein, and this effect is evident when incorporating legume proteins into food products. The increased levels of protein in such foods are found to be more satiating by consumers, while also eliciting improved postprandial hormone responses, suggesting they would aid in improving metabolic health. The incorporation of legumes into foods may reduce the consumer acceptance of such products. However, by utilizing a combination of food processing techniques, the sensory properties of legumes can be effectively manipulated to improve the acceptability of legume-enriched food products. Thus, the incorporation of legume protein into foods appears to be a viable strategy to encourage legume consumption and improve overall health. [Display omitted] • Food processing enhances the protein digestibility of legume-enriched foods. • The incorporation of legumes into foods enhances satiation and satiety. • A balance between glycaemic responses and protein digestibility must be considered. • Food processing can improve the consumer acceptability of legume-enriched foods. [ABSTRACT FROM AUTHOR]

• Estradiol reduced water intake in response to 24 and 48 h water deprivation. • Estradiol reduced water intake through changes in drinking burst number. • Activation of estrogen receptor alpha reduced licks for water. • Estradiol produced a leftward shift in the dose-response curve of exendin-4. It is well documented that estrogens inhibit fluid intake. Most of this research, however, has focused on fluid intake in response to dipsogenic hormone and/or drug treatments in euhydrated rats. Additional research is needed to fully characterize the fluid intake effects of estradiol in response to true hypovolemia. As such, the goals of this series of experiments were to provide a detailed analysis of water intake in response to water deprivation in ovariectomized female rats treated with estradiol. In addition, these experiments also tested if activation of estrogen receptor alpha is sufficient to reduce water intake stimulated by water deprivation and tested for a role of glucagon like peptide-1 in the estrogenic control of water intake. As expected, estradiol reduced water intake in response to 24 and 48 h of water deprivation. The reduction in water intake was associated with a reduction in drinking burst number, with no change in drinking burst size. Pharmacological activation of estrogen receptor alpha reduced intake. Finally, estradiol-treatment caused a leftward shift in the behavioral dose response curve of exendin-4, the glucagon like peptide-1 agonist. While the highest dose of exendin-4 reduced 10 min intake in both oil and estradiol-treated rats, the intermediate dose only reduced intake in rats treated with estradiol. Together, this series of experiments extends previous research by providing a more thorough behavioral analysis of the anti-dipsogenic effect of estradiol in dehydrated rats, in addition to identifying the glucagon like peptide-1 system as a potential bioregulator involved in the underlying mechanisms by which estradiol reduces water intake in the female rat. [ABSTRACT FROM AUTHOR]

Memory and cognitive processes influence the amount of food consumed during a meal, yet the neurobiological mechanisms mediating these effects are poorly understood. The hippocampus (HPC) has recently emerged as a brain region that integrates feeding-relevant biological signals with learning and memory processes to regulate feeding. We investigated whether the gut-derived hormone ghrelin acts in the ventral HPC (vHPC) to increase meal size through interactions with gut-derived satiation signaling. Interactions between vHPC ghrelin signaling, gut-derived satiation signaling, feeding, and interoceptive discrimination learning were assessed via rodent behavioral neuropharmacological approaches. Downstream neural pathways were identified using transsynaptic virus-based tracing strategies. vHPC ghrelin signaling counteracted the food intake–reducing effects produced by various peripheral biological satiation signals, including cholecystokinin, exendin-4 (a glucagon-like peptide-1 receptor agonist), amylin, and mechanical distension of the stomach. Furthermore, vHPC ghrelin signaling produced interoceptive cues that generalized to a perceived state of energy deficit, thereby providing a potential mechanism for the attenuation of satiation processing. Neuroanatomical tracing identified a multiorder connection from vHPC neurons to lateral hypothalamic area orexin (hypocretin)-producing neurons that project to the laterodorsal tegmental nucleus in the hindbrain. Lastly, vHPC ghrelin signaling increased spontaneous meal size via downstream orexin receptor signaling in the laterodorsal tegmental nucleus. vHPC ghrelin signaling increases meal size by counteracting the efficacy of various gut-derived satiation signals. These effects occur via downstream orexin signaling to the hindbrain laterodorsal tegmental nucleus, thereby highlighting a novel hippocampus-hypothalamus-hindbrain pathway regulating meal size control. [ABSTRACT FROM AUTHOR]

Background Longer oral processing decreases food intake. This can be attributed to greater oro-sensory exposure (OSE) and a lower eating rate (ER). How these factors contribute to food intake, and the underlying physiological mechanisms, remain unclear. Objectives We aimed to determine the independent and simultaneous effects of OSE and ER on satiation and associated endocrine responses. Methods Forty participants in study 1 [mean ± SD age: 24 ± 4 y; BMI (in kg/m2): 22 ± 2] and 20 in study 2 (mean ± SD age: 23 ± 3 y; BMI: 23 ± 2) participated in a 2 × 2 randomized trial. In both studies, participants ate chocolate custard with added caramel sauce (low OSE) or caramel fudge (high OSE) and with short (fast ER) or long breaks (slow ER) in between bites, until fullness. In study 2, endocrine responses were measured during the meal. Results In study 1, participants ate (mean ± SEM) 42 ± 15 g less in the slow- than in the fast-ER condition, only within the high-OSE condition (P  = 0.04). In study 2, participants ate 66 ± 21 g less in the high- than in the low-OSE condition and there were no intake differences between slow and fast ER (P  = 0.35). Eight minutes after starting to eat, insulin concentrations increased by 42%–65% in all treatments compared with the control. At the end of the meal, insulin concentrations were 81% higher in the high-OSE, slow-ER than in the low-OSE, fast-ER condition (P  = 0.049). Pancreatic polypeptide (PP) increased by 62%, 5 min after meal onset in the low-OSE, fast-ER condition (P  = 0.005). Ghrelin concentrations did not change. Conclusions Greater OSE increases insulin responsiveness. In contrast, PP responses are stronger when OSE is reduced and ER is fast. Insulin and PP responses may mediate the independent effects of OSE and ER on food intake. These may be beneficial eating strategies, particularly for type 2 diabetic patients, to control food intake and maintain glucose homeostasis. This trial was registered at trialregister.nl as NL6544. [ABSTRACT FROM AUTHOR]

Associative learning is often studied using food reward as the unconditioned stimulus (US). With warm-blooded species, to get the subject more motivated the solution has been to feed less, making the subject hungrier. Here we show the opposite with zebrafish. We randomly assigned zebrafish to two groups: a once-a-day-fed and a five-times-a-day-fed group, with the same amount of food fed per occasion for fish of both groups, a feeding regimen that lasted for three months. Subsequently, we trained fish by pairing food (US) with a red cue card (the conditioned stimulus, CS), which were placed together in one arm of a plus-maze across eight training sessions. We also ran unpaired training, in which the CS and US were presented in different arms. We found the previously once-a-day-fed zebrafish to consume less food throughout habituation and training sessions compared to the previously five-times-a-day-fed ones. Furthermore, five-times-a-day-fed fish in the paired group swam significantly closer to the CS during a post-training probe trial compared to the five-times-a-day-fed unpaired fish, a paired training effect that was absent in once-a-day-fed fish. Groups did not differ in health or general activity. In sum, elevated chronic feeding improved food consumption and enhanced learning and memory performance without affecting activity levels in adult zebrafish. • Food is an excellent rewarding stimulus with which previously neutral stimuli may be paired. • In most species, hungry subjects learn better in food rewarded tasks than well-fed ones. • In zebrafish, we found the opposite: chronically increased feeding led to increased motivation to eat. • Chronically increased feeding led to better learning/memory performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Honey bees can detect nicotine at 0.1 mM or greater concentration in sucrose solution. • Nicotine concentrations 1 mM or greater reduce feeding in a no choice assay. • Chronic nicotine consumption reduces acquisition. • Nicotine and satiation state interact to influence acquisition and memory. In insects, nicotine activates nicotinic acetylcholine receptors, which are expressed throughout the central nervous system. However, little work has been done to investigate the effects of chronic nicotine treatment on learning or other behaviors in non-herbivorous insects. To examine the effects of long term nicotine consumption on learning and memory, honey bees were fed nicotine containing solutions over four days. Bees were able to detect nicotine at 0.1 mM in sucrose solutions, and in a no choice assay, bees reduced food intake when nicotine was 1 mM or higher. Treatment with a low dose of nicotine decreased the proportion of bees able to form an associative memory when bees were conditioned with either a massed or spaced appetitive olfactory training paradigm. On the other hand, higher doses of nicotine increased memory retention and the proportion of bees responding to the odor during 10 min and 24 h recall tests. The reduction in nicotine containing food consumed may also impact response levels during learning and recall tests. These data suggest that long term exposure to nicotine has complex effects on learning and memory. [ABSTRACT FROM AUTHOR]

This paper investigates the role of the outside good utility function on admissible substitution patterns in multiple discrete/continuous demand models. We first present a set of novel results that characterize the functional form of quantity price effects within this class of models. The results highlight the relative inflexibility of many standard outside good utility functions. We then propose a new outside good utility function that admits more flexible marginal utility curves. Our empirical analysis uses household scanner panel data from the potato chip category, where we find empirical support for non-standard rates of satiation for the outside good. We then show how the restrictive substitution patterns induced by standard utility specifications may distort price elasticities and the evaluation of loyalty coupon targeting programs. • Analytical derivation of elasticities as a function of outside good is offered. • New outside good utility specification is introduced via hyperbolic function. • Hyperbolic utility for outside good allows for more flexible substitution pattern. [ABSTRACT FROM AUTHOR]

Cannabis (delta-9-tetrahydrocannabinol), a nonselective cannabinoid-receptor agonist, relieves nausea and pain. Cannabidiol (CBD), a cannabinoid receptor 2 inverse agonist with central effects, also reduces gut sensation and inflammation. We compared the effects of 4 weeks of treatment with pharmaceutical CBD vs placebo in patients with idiopathic or diabetic (diabetes mellitus) gastroparesis. We performed a randomized, double-blinded, placebo-controlled study of CBD twice daily (Epidiolex escalated to 20 mg/kg/d; Jazz Pharmaceuticals, Dublin, Ireland) in patients with nonsurgical gastroparesis with delayed gastric emptying of solids (GES). Symptoms were assessed by the Gastroparesis Cardinal Symptom Index Daily Diary. After 4 weeks of treatment, we measured GES, gastric volumes, and Ensure (Abbott Laboratories, Abbott Park, IL) satiation test (1 kcal/mL, 30 mL/min) to assess volume to comfortable fullness and maximum tolerance. Patients underwent specific FAAH and CNR1 genotyping. Statistical analysis compared 2 treatments using analysis of variance including baseline measurements and body mass index as covariates. Among 44 patients (32 idiopathic, 6 diabetes mellitus type 1, and 6 diabetes mellitus type 2), 5 patients did not tolerate full-dose escalation; 3 withdrew before completing 4 weeks of treatment (2 placebo, 1 CBD); 95% completed 4 weeks of treatment and diaries. Compared with placebo, CBD reduced the total Gastroparesis Cardinal Symptom Index score (P =.008), inability to finish a normal-sized meal (P =.029), number of vomiting episodes/24 hours (P =.006), and overall symptom severity (P =.034). Patients treated with CBD had a higher volume to comfortable fullness and maximum tolerance and slower GES. FAAH rs34420 genotype significantly impacted nutrient drink ingestion. The most common adverse events reported were diarrhea (14 patients), fatigue (8 patients), headache (8 patients), and nausea (7 patients). CBD provides symptom relief in patients with gastroparesis and improves the tolerance of liquid nutrient intake, despite slowing of GES. ClinicalTrials.gov NCT #03941288. [ABSTRACT FROM AUTHOR]

Highlights • Increased chewing is known to enhance satiation. • Hydrogels were engineered to vary in chewing and oral lubrication. • Gels were then consumed by volunteers before a snack. • A 32% reduction in snack intake followed the low chewing/high lubricating gel. • Lubrication therefore may offer a construct to promote satiation. Abstract As overeating, overweight and obesity remain public health concerns, it is crucial to design satiety-enhancing foods that suppress appetite and lower snack intake. Existing research identifies oro-sensory targets to promote satiation and satiety, yet it remains unclear as to whether it is 'chewing' or 'oral lubrication' that might amplify satiation signals. In this study, techniques from experimental psychology, food material science and mechanical engineering have been combined to develop model foods to investigate the role of chewing and oral lubrication on food intake. Novel model gels, similar in pleasantness, were given as a preload then their effects on subjective appetite and intake of a salty snack were measured in a between-subjects design. Three mint flavoured hydrogels were engineered to vary in their texture (fracture stress) and lubrication (inverse of coefficient of friction), and a control group received mint tea. Results showed that snack intake was suppressed by 32% after eating the low chewing/high lubricating preload compared to the high chewing/low lubricating preload (p < 0.05). Hunger ratings decreased from t 1 to t 3 (p < 0.05), however differences between conditions were subtle and not significant. Thus, this proof-of-concept study demonstrates that manipulating oral lubrication is a promising new construct to reduce snack intake that merits future research in the oro-sensory satiety domain. [ABSTRACT FROM AUTHOR]

Abstract The main prey of the Atlantic mackerel undertake diel vertical migrations, however diel and vertical patterns in the feeding by mackerel remains poorly known thus limiting our understanding and quantification of ecosystem trophodynamics and potentially influencing stock assessment and ecosystem based management. By intensive monitoring of adult Atlantic mackerel and its prey during summer in the Irminger Sea, it was found that the diel feeding cycle is of high quantitative importance. Fresh stomach content analysis indicated a marked diel pattern with copepods as the main prey between 16 and 24 (solar time), and euphausiids/myctophids between 22 and 08. Compared with the zooplankton distribution and composition, there were no indications of feeding below the mixed layer. Mackerel selected for the largest and most energy rich prey, namely copepods with prosome lengths >2 mm, and then switched from copepods to euphausiids/myctophids around midnight, despite that the copepods were also aggregated during night. Stomach fullness increased significantly with length and condition, suggesting that individuals that were larger were more effective feeders. The stomach content by weight primarily consisted of copepods (65%, exclusively Calanus finmarchus), euphausiids (18%), and to a lesser extent teleosts (5%, mainly myctophids), hyperiids (4%) and cephalopods (2%). The results are likely widely applicable in the main feeding season and areas (the oceanic parts of the Nordic Seas during summer), because of similarities in the diet of the adult mackerel and in the prey's diel vertical migration. In conclusion, it is imperative to account for the diel dynamics when quantifying the mackerel diet and its impact on prey populations. [ABSTRACT FROM AUTHOR]

The use of neuroimaging tools, especially functional magnetic resonance imaging, in nutritional research has increased substantially over the past 2 decades. Neuroimaging is a research tool with great potential impact on the field of nutrition, but to achieve that potential, appropriate use of techniques and interpretation of neuroimaging results is necessary. In this article, we present guidelines for good methodological practice in functional magnetic resonance imaging studies and flag specific limitations in the hope of helping researchers to make the most of neuroimaging tools and avoid potential pitfalls. We highlight specific considerations for food-related studies, such as how to adjust statistically for common confounders, like, for example, hunger state, menstrual phase, and BMI, as well as how to optimally match different types of food stimuli. Finally, we summarize current research needs and future directions, such as the use of prospective designs and more realistic paradigms for studying eating behavior. [ABSTRACT FROM AUTHOR]

Highlights: • Lower thickness increased ONS intake by 33% without affecting satiation or satiety. • Sweetness intensity did not affect ONS intake. • Sensory sequential profiling showed that mouth-drying increased quadratically. • The change in mouth-drying possibly acts as a cue to halt intake. Abstract Oral nutritional supplements (ONS) can be used to improve the nutritional status of malnourished patients, but their effectiveness depends on adequate intake. This is not always achieved due to the disliked flavour and satiating properties of ONS. The aim of this study was to investigate the effect of sweetness intensity and thickness on intake and sensory sequential profile of an ONS. It was hypothesized that lower sweetness intensity and thickness would decrease oro-sensory stimulation and satiety, improve the sensory profile, and thus, improve ONS intake. The effect of sweetness intensity and thickness on intake and satiety was investigated using a 2 × 2 design (low-high-sweetness and thin/thick). Participants (n = 36) consumed each ONS to satiation. Each ONS was identical in macronutrient and calorie content. Appetite and thirst were measured throughout the morning of the test. Additionally, an expert sensory panel (n = 11), performed a sensory sequential profile of each ONS. No effect of sweetness intensity was found. Results showed that 33% more of the thin, compared to thick, ONS was consumed, without affecting satiety. Furthermore, mouth-drying first increased, up to a consumption volume of 300 ml, and then decreased, independent of sweetness intensity and thickness. In conclusion, this study showed that an ONS with lower thickness increased intake in healthy adults, without affecting satiety. This implies that, for ONS, attention should not be solely focused on nutritional content. Instead, a sensory-nutrition approach is recommended that balances nutritional content with oro-sensory cues. This proof of concept should be further investigated with malnourished older adults. [ABSTRACT FROM AUTHOR]

Previous research has suggested that operant response decrements within experimental sessions are due in part to habituation to the repeated presentation of reinforcers. One way to assess the role of habituation in within-session response decrements is to conduct a test for dishabituation, a phenomenon in which a habituated response to a given stimulus recovers following the presentation of some strong or novel stimulus other than the habituated stimulus. Dishabituation of operant responding has been demonstrated on several occasions in the literature, but studies with non-human subjects have thus far been limited to those using rats and pigeons. Two experiments attempting to replicate these findings with mice were conducted. Two groups of mice nose-poked for a sweetened condensed milk/water reinforcer on either a fixed-ratio 4 or variable-interval 15 s schedule of reinforcement. During testing, baseline sessions were then alternated with two test conditions and a control condition. Test conditions included a 5 s auditory stimulus or flashing of the house light presented mid-session. Control conditions were identical to baseline. Dishabituation was not observed for either group in Experiment 1. In Experiment 2, dishabituation was not observed for the fixed-ratio 4 group but was observed for the variable interval 15 s group. Considerations for further study of operant dishabituation in mice are discussed. • Habituation to reinforcers contributes to within-session operant response decrements. • Brief auditory or visual stimulus presentations have produced dishabituation in rats, pigeons, and humans. • In two experiments, two groups of mice nose-poked for a milk mixture on a fixed-ratio or variable-interval schedule. • In Exp 1, house light flash or tone presented 10 min into session did not produce dishabituation for either group. • In Exp 2, flash and white noise presented 5 min into session produced dishabituation for mice in variable-interval group. [ABSTRACT FROM AUTHOR]

• A non-linear association exists between meal caloric intake and meal energy density. • Meal caloric intake increases with energy density in lower energy-dense meals. • Meal caloric intake decreases slightly with energy density in higher energy-dense meals. • The non-linear pattern in meal caloric intake suggests that human are sensitive to calories. • The results lend further support for our two-component theoretical model of meal size (g). Previously, we demonstrated a non-linear association between meal caloric intake and meal energy density (ED, kcal/g) in data from a controlled trial in the US and from free-living participants in the UK [1]. In both datasets, meal caloric intake increased with ED in lower energy-dense meals (below ∼1.75 kcal/g) and decreased in higher energy-dense meals (above ∼1.75 kcal/g). In the current study, we sought to explore whether this pattern extends to data from free-living participants in Argentina (N = 2738 meals) and Malaysia (N = 4658 meals). Again, a significant breakpoint was found in both the Argentinean (2.04 kcal/g (SE = 0.06)) and Malaysian (2.17 kcal/g (SE = 0.06)) datasets with mean centered meal caloric intake increasing with ED below the breakpoint and decreasing above the breakpoint. These results lend further support for our two-component theoretical model of meal size (g) in which a volume signal is dominant in lower energy-dense meals and a calorie-content signal is dominant in higher energy-dense meals. Together, our research adds to evidence supporting human sensitivity to calories and exposes a complexity in the correspondence between meal energy content and meal size in everyday (non-manipulated) meals. Further research is needed to provide causal evidence for this sensitivity and whether individual variation impacts meal size and energy balance. [ABSTRACT FROM AUTHOR]

Highlights • Visitors who follow an ordered route as well as those who anticipate the content become more satiated. • Longer visit and anticipating the content diminish visitors' emotional response. • Visitors follow a self-regulatory process and adapt the time spent to their level of satiation. • The level of attention might be low if the visit is too short or if the content is not anticipated. Abstract Museums seek to provide visitors with memorable experiences. However, some visitors experience a hedonic decline and satiation after their visit. The present research aims to evaluate how the time spent, the route, and the anticipation of the visit might either prevent or further visitor satiation. A field study and a field experiment are performed. Findings reveal that spending more time in the museum and anticipating the content can increase the perceived satiation and diminish visitors' emotional response, although the attention level diminishes for short visits and when the content is not anticipated. In a real context, following a free route reduces perceived satiation, with visitors following a self-regulatory process and adapting the time spent to the level of satiation. [ABSTRACT FROM AUTHOR]

Background Appetite regulating properties of foods are usually investigated under laboratory conditions, whereas in real life, foods are consumed under at home conditions. The objective of this study was to compare the acute effects of breakfasts when tested in a laboratory condition and in an at home condition. Appetite regulating properties of two bread breakfasts and two cereal breakfasts were also compared. Subjects and methods In this randomized cross-over trial balanced for laboratory and at home test conditions, thirty-two women consumed five breakfasts, i.e. two bread breakfasts, two cereal breakfasts and one fried-egg breakfast. Visual analogue scales for measuring appetite were captured via an on-line scoring system and were analyzed as incremental area under the curve, as satiation phase and as satiety phase. Results Location effects were limited to two small effects only. An overall location effect in hunger feelings was observed (p = 0.040), which occurred specifically during the short satiation period (p = 0.0002) where hunger feelings scored higher under laboratory conditions. Similarly, a location effect was observed for desire to eat (p = 0.001); this was again higher under laboratory conditions. No other location effects were observed. Bread breakfasts did not differ in their appetite regulating properties. The Steel Cut oatmeal breakfast was reported to be more satiating (p = 0.001) as compared to the ready-to-eat cereal. Conclusions Whereas the five breakfasts varied somewhat in their appetite regulating properties, evaluation under laboratory conditions overall did not result in different appetite scores compared to the at home conditions. This suggests that at home testing may be a useful alternative to laboratory test conditions for nutrition research. [ABSTRACT FROM AUTHOR]

Background: Low energy-dense (LED) foods reduce energy intake (EI); whether this effect is sustained over time and during weight loss is unknown.Objective: This trial examined the effects of LED compared with high energy-dense (HED) meals on appetite, EI, and control over eating in the laboratory and during a weight-management program that encourages unrestricted intake of LED foods [Slimming World, UK (SW)] compared with a self-led Standard Care program [NHS weight-loss plan (SC)].Methods: Overweight and obese women [n = 96; mean ± SD age: 41.03 ± 12.61 y; mean ± SD body mass index (in kg/m2): 34.00 ± 3.61] were recruited from the SW or SC programs. Primary outcomes included appetite, food preferences (liking and wanting for LED and HED foods), cravings, and evening meal EI (LED, HED) in response to calorie-matched LED (≤0.8 kcal/g) and HED (≥2.5 kcal/g) breakfast and lunch meals. Probe-day tests were conducted at weeks 3 and 4 and repeated at weeks 12 and 13 in a within-day crossover design. Secondary outcomes, including body weight and program experience, were measured from weeks 1 to 14 in a parallel-group design. Dietary compliance was monitored with the use of weighed food diaries at weeks 3 and 12.Results: Intention-to-treat (ITT) and completers analyses showed that the SW group lost more weight than the SC group [ITT: -5.9% (95% CI: -4.7%, -7.2%) compared with -3.5% (-2.3%, -4.8%), P < 0.05; completers: -6.2% (-4.8%, -7.6%) compared with 3.9% (-2.5%, -5.2%), P < 0.05]. The SW group reported greater control over eating and more motivation to continue the program compared with the SC group. LED meals increased sensations of fullness and reduced hunger on probe days (P < 0.001). Total-day EI was 1057 ± 73 kcal less (95% CI: 912, 1203 kcal; 36%) under LED compared with HED conditions (P < .001). Liking for LED and HED foods and wanting for HED foods were lower before lunch under LED compared with HED conditions, and liking decreased to a greater extent after the LED lunch. The SW group reported fewer cravings under LED compared with HED conditions (P < 0.05). On probe days, appetite and EI outcomes did not differ between weeks 3 and 12 or between the SW and SC groups.Conclusion: LED meals improve appetite control in women attempting weight loss and the effect is sustainable. Consumption of LED meals likely contributed to weight loss in the SW program. This study was registered at clinicaltrials.gov as NCT02012426. [ABSTRACT FROM AUTHOR]

Food liking influences hunger and fullness, however, the direction of this influence has remained unclear due to the difficulty in capturing the complexity of hunger and fullness feelings and the subjective nature of evaluating food liking. The objective of this study was to investigate the impact of food liking on feelings of hunger and fullness utilizing the 5-Factor Satiety Questionnaire. Thirty participants attended two breakfast sessions one week apart in which they evaluated hunger and fullness feelings produced by two equal-caloric smoothies that differed only in that one contained a bittering agent to lower liking. Levels of the bittering agent were determined from a screening procedure and were panelist specific. Evaluations were made at 0 min, 60 min, 120 min, and 180 min after consumption. Food intake from a snack offered three hours after breakfast was covertly recorded. The more palatable control smoothie provided significantly greater mental fullness factor sensations over the three-hour testing period than the bitter smoothie. Physical fullness factor ratings were initially higher for the bitter smoothie than the control smoothie, but dropped to a nearly equal level two hours after consumption. Mental and physical hunger factor sensations were nearly equal between the two smoothies over the three hour testing period. Subjects consumed on average 77 more calories from the snack following the bitter smoothie in comparison to the control. These findings suggest that if people eat a food they greatly enjoy, instead of eating a less-well-liked version, they will experience more pleasure, satisfaction, and satiety. [ABSTRACT FROM AUTHOR]

The purpose of this study is to examine aspects of operant behavior-modeled economic choice for food in rats in closed economy protocols in which food is available for only a few discrete times per daily 23-h session, designed to emulate clustering of human food intake into meals. In the first experiment, rats performed lever press responses for food pellets in an ascending series of ratios or fixed unit prices (FUP) when food was available for four 40-min food opportunities (FO) per day. Daily intake at low FUP was comparable to ad libitum intakes. Intake declined as FUP increased and was not distributed equally among the four FOs. In particular, the last FO of a session (occurring at about lights on in a 12:12 cycle) was the smallest, even when total intake was low due to the response requirement at high FUP. Within FOs, satiation was evident at low FUPs by a decrease in rate of intake across a 40 min FO; at high FUPs responding was evenly distributed. In the second experiment, rats had a choice of responding on two levers for either intermittent inexpensive (II; low FUP according to a four FO schedule) or costly continuous (CC; 20-fold higher FUP but available throughout 23-h sessions) food. Most (73%) of the rats consistently chose almost all of their food from the II source. Further, as the timing of the four II FOs were changed relative to the light: dark Zeitgeber, the time of the smallest meal changed such that the smallest meal (s) were during the light period regardless of ordinal position within a session. These data are discussed in terms of economic and Zeitgeber effects on consumption when food is available intermittently, and are contrasted with results from comparable protocols in mice. [ABSTRACT FROM AUTHOR]

Oro-sensory exposure (OSE) is an important factor in the regulation of food intake with increasing OSE leading to lower food intake. Oral processing time and taste intensity both play an important role in OSE but their individual contribution to satiation is unknown. We aimed to determine the independent and combined effects of oral processing time and taste intensity on satiation. Fifty eight participants (23 ± 9 y, BMI 22 ± 2 kg/m 2 ) participated in a 2 × 2 factorial randomized crossover study in which they consumed one of four gel-based model foods until satiation during four sessions. Model foods were offered ad libitum and differed in texture (soft or hard texture, yielding shorter and longer oral processing time) and sweetness (low or high intensity). Model foods were isocaloric and were matched for flavor and palatability. Outcome measures were intake of the model food and the microstructure of eating behavior, such as number of chews and eating rate. There was an overall significant effect of texture ( p < 0.001) but not sweetness ( p = 0.33) on intake with a 29.2% higher intake of the soft model foods compared to the hard model foods. After correction for palatability the difference in intake between the soft and hard model foods was 21.5% ( p < 0.001). The number of chews was significantly lower for the soft (10.1 ± 6.2) than for the hard (26.9 ± 6.2) model foods ( p < 0.001), which resulted in a significantly lower eating rate (soft, 26.3 ± 10.2 and hard, 15.3 ± 7.1 g/min, p < 0.001). These results show that increasing texture hardness of gel model foods decreases food intake independent of sweet taste intensity. The higher number of chews and faster eating rate may cause this effect. In conclusion, oro-sensory exposure duration rather than taste intensity appears to be the main determinant of food intake. [ABSTRACT FROM AUTHOR]

Greater rates of intermittent reinforcement in the presence of discriminative stimuli generally produce greater resistance to extinction, consistent with predictions of behavioral momentum theory. Other studies reveal more rapid extinction with higher rates of reinforcers – the partial reinforcement extinction effect. Further, repeated extinction often produces more rapid decreases in operant responding due to learning a discrimination between training and extinction contingencies. The present study examined extinction repeatedly with training with different rates of intermittent reinforcement in a multiple schedule. We assessed whether repeated extinction would reverse the pattern of greater resistance to extinction with greater reinforcer rates. Counter to this prediction, resistance to extinction was consistently greater across twelve assessments of training followed by six successive sessions of extinction. Moreover, patterns of responding during extinction resembled those observed during satiation tests, which should not alter discrimination processes with repeated testing. These findings join others suggesting operant responding in extinction can be durable across repeated tests. [ABSTRACT FROM AUTHOR]

Background: Limited information exists on the relation between fat emulsion structure and its effect on the release of gastrointestinal hormones and feelings of satiation.Objective: We investigated the impact of fat emulsion droplet size, gravitational and acid stability, and redispersibility on gastrointestinal responses and sought to deduce the relative importance of the hormones ghrelin, cholecystokinin, glucagon-like peptide-1, and peptide YY (PYY) in controlling fat emptying and related satiation.Methods: Within a randomized, double-blind, 4-armed crossover study, an extensive data set was generated by MRI of gastric function, analysis of hormone profiles, and ratings of satiation in healthy participants [10 women and 7 men with a mean ± SD age of 25 ± 7 y and body mass index (in kg/m2) of 22 ± 1] after intake of 4 different fat emulsions. Iterative Bayesian model averaging variable selection was used to investigate the influence of hormone profiles in controlling fat emulsion emptying and satiation.Results: The emulsion structure had a distinct effect on the gastric emptying (primary outcome), gastrointestinal hormone profiles, and ratings of satiation (secondary outcomes). Gravitational and acid stability were stronger modulators of fat emptying and hormone profiles than were emulsion droplet size or redispersibility. Cholecystokinin and PYY were most strongly affected by fat emulsion instability and droplet size. Although both hormones were relevant predictors of gastric emptying, only PYY was identified as a relevant predictor of satiation.Conclusions: This work indicates that evenly dispersed, stable, small-emulsion droplets within the stomach lead to prolonged gastric distension, longer ghrelin suppression, and accelerated fat sensing (cholecystokinin and PPY), triggering prolonged feelings of satiation. It suggests that the effects of emulsion instability and droplet size on energy consumption are best studied by assessing changes in gastric emptying and ratings of satiation rather than changes in venous hormone profiles. This trial was registered at clinicaltrials.gov as NCT01253005. [ABSTRACT FROM AUTHOR]

Background: Attempts to model cumulative intake curves with quadratic functions have not simultaneously taken gustatory stimulation, satiation, and maximal food intake into account. Objective: Our aim was to develop a dynamic model for cumulative intake curves that captures gustatory stimulation, satiation, and maximal food intake. Design: We developed a first-principles model describing cumulative intake that universally describes gustatory stimulation, satiation, and maximal food intake using 3 key parameters: 1) the initial eating rate, 2) the effective duration of eating, and 3) the maximal food intake. These model parameters were estimated in a study (n = 49) where eating rates were deliberately changed. Baseline data was used to determine the quality of model's fit to data compared with the quadratic model. The 3 parameters were also calculated in a second study consisting of restrained and unrestrained eaters. Finally, we calculated when the gustatory stimulation phase is short or absent. Results: The mean sum squared error for the first-principles model was 337.1 ± 240.4 compared with 581.6 ± 563.5 for the quadratic model, or a 43% improvement in fit. Individual comparison demonstrated lower errors for 94% of the subjects. Both sex (P = 0.002) and eating duration (P = 0.002) were associated with the initial eating rate (adjusted R² = 0.23). Sex was also associated (P = 0.03 and P = 0.012) with the effective eating duration and maximum food intake (adjusted R² = 0.06 and 0.11). In participants directed to eat as much as they could compared with as much as they felt comfortable with, the maximal intake parameter was approximately double the amount. The model found that certain parameter regions resulted in both stimulation and satiation phases, whereas others only produced a satiation phase. Conclusions: The first-principles model better quantifies interindividual differences in food intake, shows how aspects of food intake differ across subpopulations, and can be applied to determine how eating behavior factors influence total food intake. [ABSTRACT FROM AUTHOR]

Food-grade titanium dioxide (E171) is a widely used food additive and the toxicity after oral consumption is still under research, although it has been already banned in some countries. The consumption of this additive occurs mainly through ultra-processed food products which also contain high amounts of fat. High fat diets (HFD) impair the physiological system controlling satiation and satiety, which are responsible for control of food intake and energy status. The impact of E171 on animal behavior has been poorly explored and here we hypothesize that E171 could worsen the effects on feeding behavior induced by HFD. Therefore, we aimed to evaluate the effects of E171 on the feeding pattern and the behavioral satiety sequence (BSS) of mice fed with a regular diet (RD) or a HFD after 1 and 16 weeks of exposure. The results showed that RD + E171 increased food intake and feeding time, but the prototypical structure of the BSS pattern (feeding→ grooming-activity → resting), was preserved. Conversely, food consumption was not altered in HFD + E171, but the BSS pattern was disrupted as the animals prolonged resting time and spent less time being active. Our findings suggest that E171 delayed the onset of satiation in mice fed with RD but induced the opposite effect in mice fed with HFD. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • 61 appetite-related health claim applications from the EU register were retrieved. • Six appetite-related health claims were accepted and 55 rejected by EFSA. • Seven main- and 10 sub-categories were revealed through content analysis. • The resultant framework offers a means to pre-assess future claims. From 2006 to 2020, UK nutrition and health claims were assessed by the European Food Safety Authority (EFSA) under EU Nutrition and Health Claims Regulations (2006). Since Brexit, UK applications are considered by the UK Nutrition and Health Claims Committee (UKNHCC). EFSA guidance documentation drawing together claims related to appetite ratings, weight management, and blood glucose concentrations was most recently published in 2012. 61 EFSA scientific opinions on appetite-related health claims applications from 2010 to 2020 were reviewed. Fifty-five related to hunger, fullness, energy intake, satiation and satiety were rejected, whereas three weight management claims and three blood glucose levels claims were authorised. 17 novel categories of reasons for claims application rejection were synthesised via Inductive Content Analysis (7 main-, 10 sub-categories). The resultant conceptual framework presented herein aims to support commercial pre-assessment of future appetite-related health claim applications and stimulate discussion regarding appetite-related health claims legislation in the new era of UKNHCC. [ABSTRACT FROM AUTHOR]

Food intake occurs in bouts or meals, and numerous meal-generated signals have been identified that act to limit the size of ongoing meals. Hormones such as cholecystokinin (CCK) are secreted from the intestine as ingested food is being processed, and in addition to aiding the digestive process, they provide a signal to the brain that contributes to satiation, limiting the size of the meal. The potency of CCK to elicit satiation is enhanced by elevated levels of adiposity signals such as insulin. In the present experiments we asked whether CCK and insulin interact at the level of the blood-brain barrier (BBB). We first isolated rat brain capillary endothelial cells that comprise the BBB and found that they express the mRNA for both the CCK1R and the insulin receptor, providing a basis for a possible interaction. We then administered insulin intraperitoneally to another group of rats and 15 min later administered CCK-8 intraperitoneally to half of those rats. After another 15 min, CSF and blood samples were obtained and assayed for immunoreactive insulin. Plasma insulin was comparably elevated above baseline in both the CCK-8 and control groups, indicating that the CCK had no effect on circulating insulin levels given these parameters. In contrast, rats administered CCK had CSF-insulin levels that were more than twice as high as those of control rats. We conclude that circulating CCK greatly facilitates the transport of insulin into the brain, likely by acting directly at the BBB. These findings imply that in circumstances in which the plasma levels of both CCK and insulin are elevated, such as during and soon after meals, satiation is likely to be due, in part, to this newly-discovered synergy between CCK and insulin. [ABSTRACT FROM AUTHOR]

We have shown previously that mice given access to four discrete feeding opportunities (FOs) per day show a characteristic sequence of sizes across ordinal FOs. The purpose of the present experiments was to determine the relative contributions of external and internal factors on the sequencing of FO size. The external factors were the light:dark Zeitgeber and the cost of food, imposed via different fixed unit prices (FUP) in a closed operant economy, and the internal factors were signals relating to energy status including time since last food and weight loss. In the first experiment, mice were given 4 FOs spaced 4-h apart, but with the timing of the FOs relative to the Zeitgeber altered by a 4-h Zeitgeber advance or delay of the cycle. Food intake, and associated body weight, declined as price increased, but the temporal order of FO size was invariant within a Zeitgeber condition. The Zeitgeber advanced group showed clear evidence of a shift in meal sequence relating to the light:dark cycle. Thus, external factors seem to be a more important determinant of total intake and sequencing than internal factors. In the second experiment, mice were given the choice between continuous costly (CC) and intermittent inexpensive (II) food. II food was available for four-15 min intervals every 4-h, and the timing of the 15 min intervals was varied relative to the Zeitgeber cycle. In spite of a 20-fold difference in price between CC and II food, mice took approximately equal amounts from each, and all food intake took place during the dark phase. Mice consumed II food only if it was available during the dark phase. Food intake was strongly linked to the light:dark cycle, largely independent of food cost. [ABSTRACT FROM AUTHOR]

Sensory information from the gastrointestinal system can be transmitted to the brain through the vagus nerve, the intermediate-caudal region of the nucleus of the solitary tract (NST), and various subnuclei of the parabrachial complex, notably the external lateral subnucleus (LPBe). The objective of the present study was to examine the relevance of this subnucleus in satiation and food reintake after gastrointestinal food removal. LPBe-lesioned animals were subjected to a re-intake task following the partial withdrawal of gastric food contents shortly after satiation. Lesioned and control animals ingested a similar amount of the initial liquid meal. However, after withdrawal of one-third of the food consumed, LPBe-lesioned rats were not able to compensate for the deficit created, and their re-intake of food was significantly lower than the amount withdrawn after the satiating meal. In contrast, the food re-intake of control animals was similar to the amount withdrawn. Hence, the LPBe does not appear to be critical in the satiation process under the present experimental conditions. However, the LPBe may be part of a system that is essential in rapid visceral adjustments related to short-term food intake, as also shown in other gastrointestinal regulatory behaviors that require immediate processing of visceral sensory information. [ABSTRACT FROM AUTHOR]

Previous studies have shown that food texture affects satiation by influencing the eating rate, bite size and oral transit time. However, investigations into the direct effect of texture on satiation are limited. The objective of the current study was to investigate the effect of textural complexity on satiation, independent of oral processing time and energy density. A preload-test meal design was used in this study; model foods with three levels of textural complexity (low, medium and high) were consumed as preload foods followed by a two-course ad libitum meal. This study was a randomized cross-over trial with 38 subjects. The results clearly showed that food with greater textural complexity led to significantly lower food intake overall. The first course of the meal and total food intake was significantly reduced ( p < 0.05) although food intake at the second course did not differ between groups. Despite the differing total intake, all subjects rated to have the same sense of satiety after three hours post-trial and the time taken to the next eating occasion did not differ between different preload conditions. Increased textural complexity in food enhances satiation and may potentially impact on satiety however this needs to be further confirmed in future studies. The findings suggest that foods with more complex textures can be a helpful tool in reducing the short-term food intake and enhancing the satiation response. [ABSTRACT FROM AUTHOR]

Contrafreeloading involves organisms working for food when an identical source of food is freely available. The present study assessed whether training reinforcement rates influenced contrafreeloading by arranging a within-subject and within-session design using pigeons. Across different alternating discriminative stimuli, variable-interval schedules arranged leaner (30 per hour) and richer (120 per hour) rates of food reinforcement. Responding decreased but persisted in the presence of free food during the session (i.e., contrafreeloading). Further, responding tended to be similar between components initially but greater persistence emerged in the richer component with additional exposure. With pre-session feeding, responding did not change systematically across test sessions and tended to be more persistent in the richer component. Greater persistence with greater training reinforcement rates is generally consistent with an influential theory of response persistence, behavioral momentum theory. However, the different patterns of responding across test sessions between pre- and within-session feeding reveals multiple behavioral processes involved in contrafreeloading that have yet to be fully understood. Behavioral momentum theory could provide a useful theoretical framework for understanding and quantifying the behavioral processes underlying contrafreeloading. [ABSTRACT FROM AUTHOR]

Background: Hormonal fluctuations during the menstrual cycle influence energy intake and expenditure as well as eating preferences and behavior. Objective: We examined the effect in healthy, overweight, premenopausal women of a diet and exercise weight-loss program that was designed to target and moderate the effects of the menstrual cycle compared with the effect of simple energy restriction. Design: A total of 60 healthy, overweight, premenopausal women were included in a 6-mo weight-loss program in which each subject consumed a diet of 1600 kcal/d. Subjects were randomly assigned to either a combined diet and exercise program that was tailored to metabolic changes of the menstrual cycle (Menstralean) or to undergo simple energy restriction (control). Results: Thirty-one women (19 Menstralean and 12 control women) completed the study [mean 6 SD body mass index (in kg/m²): 32.0 6 5.2]. Both groups lost weight during the study. In an intention-to-treat analysis, the Menstralean group did not achieve a clinically significant weight loss compared with that of the control group (P = 0.61). In per-protocol analyses, a more-pronounced weight loss of 4.3 6 1.4 kg (P = 0.002) was shown in adherent Menstralean subjects than in the control group. Conclusion: A differentiated diet and exercise program that is tailored to counteract food cravings and metabolic changes throughout the menstrual cycle may increase weight loss above that achieved with a traditional diet and exercise program in women who can comply with the program. This trial was registered at clinicaltrials.gov as NCT01622114. [ABSTRACT FROM AUTHOR]

Background: Excess fat consumption has been linked to the development of obesity. Fat and salt are a common and appetitive combination in food; however, the effect of either on food intake is unclear. Fat taste sensitivity has been negatively associated with dietary fat intake, but how fat taste sensitivity influences the intake of fat within a meal has, to our knowledge, not yet been investigated.Objectives: Our objectives were, first, to investigate the effects of both fat and salt on ad libitum food intake and, second, to investigate the effects of fat taste sensitivity on satiation responses to fat and whether this was affected by salt.Methods: Forty-eight healthy adults [16 men and 32 women, aged 18-54 y, body mass index (kg/m(2)): 17.8-34.4] were recruited and their fat taste sensitivity was measured by determination of the detection threshold of oleic acid (18:1n-6). In a randomized 2 × 2 crossover design, participants attended 4 lunchtime sessions after a standardized breakfast. Meals consisted of elbow macaroni (56%) with sauce (44%); sauces were manipulated to be1) low-fat (0.02% fat, wt:wt)/low-salt (0.06% NaCl, wt:wt),2) low-fat/high-salt (0.5% NaCl, wt:wt),3) high-fat (34% fat, wt:/wt)/low-salt, or4) high-fat/high-salt. Ad libitum intake (primary outcome) and eating rate, pleasantness, and subjective ratings of hunger and fullness (secondary outcomes) were measured.Results: Salt increased food and energy intakes by 11%, independent of fat concentration (P= 0.022). There was no effect of fat on food intake (P= 0.6), but high-fat meals increased energy intake by 60% (P< 0.001). A sex × fat interaction was found (P= 0.006), with women consuming 15% less by weight of the high-fat meals than the low-fat meals. Fat taste sensitivity was negatively associated with the intake of high-fat meals but only in the presence of low salt (fat taste × salt interaction on delta intake of high-fat - low-fat meals;P= 0.012).Conclusions: The results suggest that salt promotes passive overconsumption of energy in adults and that salt may override fat-mediated satiation in individuals who are sensitive to the taste of fat. This trial was registered at the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au) as ACTRN12615000048583. [ABSTRACT FROM AUTHOR]

An increase in subjective feelings of thirst and ad libitum drinking caused by an increase in serum osmolality have been observed following high intensity intermittent exercise (HIIE) compared to continuous exercise. The increase in serum osmolality is closely linked to the rise in blood lactate and serum sodium concentrations. However, during an ensuing recovery period after HIIE when serum osmolality will decrease, the resultant effect on sensations of thirst and subsequent water intake is unclear. Therefore the aim of the study was to assess the sensations of thirst and subsequent effect on ad libitum water consumption when water intake was immediately allowed, delayed or prevented following a period of HIIE. Methods Twelve males (26 ± 4 years, 80.1 ± 9.3 kg, 1.81 ± 0.05 m, V ̇ O 2peak 60.1 ± 8.9 ml·kg − 1 ·min − 1 ) participated in three randomised trials undertaken 7–14 days apart. Participants rested for 30 min then completed a 60 min HIIE exercise period (20 × 1 min at 100% V ̇ O 2peak with 2 min rest) followed by 60 min of recovery, during which ad libitum water intake was provided immediately (W), delayed until the final 30 min (W30) or not permitted (NW). Body mass was measured at the start and end of the trial. Blood lactate and serum sodium concentrations serum osmolality and sensation of thirst were measured at baseline, immediately post-exercise and during the recovery. Results Body mass loss was different between all trials (W: 0.25 ± 0.45, W30: 0.49 ± 0.37, NW: 1.29 ± 0.37%; p < 0.05). Sensations of thirst peaked post-exercise and decreased in W and W30 following water ingestion (p < 0.05). Total voluntary water intake was greater in W trial (0.846 ± 0.417 vs . 0.630 ± 0.277 l; p < 0.05) but was similar during the first 30 min period of allowed drinking (0.618 ± 0.297 vs . 0.630 ± 0.277 l; p > 0.05). Serum osmolality (299 ± 6 vs . 298 ± 5 vs . 298 ± 3 mOsmol·kg − 1 ), blood lactate (7.1 ± 1.1 vs . 7.2 ± 1.1 vs . 7.1 ± 1.2 mmol·l − 1 ) and serum sodium concentrations (142 ± 2 vs . 145 ± 2 vs . 145 ± 2 mmol·l − 1 ) peaked post-exercise (W vs . W30 vs . NW; p < 0.05) but were not different between trials (p > 0.05). Conclusions Sensations of thirst were increased following HIIE and remained until satiated by water intake. This was despite the likely primary stimulus, serum osmolality, decreasing during the recovery period following a post-exercise peak. A combined effect of reduction in blood lactate and serum sodium concentrations, restoration of plasma volume and water intake contributed to the similar decrease in serum osmolality observed throughout the trials. [ABSTRACT FROM AUTHOR]

Context CCK is understood to play a major role in appetite regulation. Difficulties in measuring CCK have limited the potential to assess its profile in relation to food-induced satiety. Improvements in methodology and progress in theoretical understanding of satiety/satiation make it timely for this to be revisited. Objective First, examine how physiologically relevant postprandial CCK8/33(s) profiles are influenced by fat (HF) or carbohydrate (HCHO) meals. Second, to examine relationships between postprandial CCK and profiles of satiety (hunger/fullness) and satiation (meal size). Participants and design Sixteen overweight/obese adults (11 females/5 males) participated in a randomised-crossover study (46 years, 29.8 kg/m 2 ) in a university research centre. Plasma was collected preprandially and for 180 min postprandially. Simultaneously, ratings of hunger/fullness were tracked for 180 min before an ad libitum lunch was provided. Results CCK8/33(s) levels increased more rapidly and reached a higher peak following HF compared to HCHO breakfast ( F (1,15) = 14.737, p < 0.01). Profiles of hunger/fullness did not differ between conditions ( F (1,15) = 0.505, p = 0.488; F (1,15) = 2.277, p = 0.152). There was no difference in energy intake from the ad libitum meal (HF-3958 versus HCHO-3925 kJ; t (14) = 0.201, p = 0.844). CCK8/33(s) profiles were not associated with subjective appetite during early and late phases of satiety; nor was there an association between CCK8/33(s) and meal size. Conclusions These results demonstrate CCK levels were higher after HF meal compared to HCHO isocaloric meal. There was no association between CCK levels and intensity of satiety, or with meal size. Under these circumstances, CCK does not appear to play a unique independent role in satiety/satiation. CCK probably acts in conjunction with other peptides and the action of the stomach. [ABSTRACT FROM AUTHOR]

Previous research has shown tangibly maintained challenging behavior can be temporarily decreased by providing presession access to the relevant tangible. However, the duration of this beneficial effect is unknown. We measured the subsequent duration of behavior reduction effects following presession access during extended classroom observation sessions by analyzing within-session patterns of responding in three children with autism. An alternating treatments design was used to analyze within- and across-session responding following presession access and presession restriction conditions. The cumulative frequency of challenging behavior was higher following the presession restriction condition for all participants and lower following presession access. Within-session analysis revealed the same basic pattern of responding across participants. Specifically, the first half of the sessions contained very little, if any, challenging behavior; however, after 60 min, the rate of challenging behavior began to increase rapidly for two of the three participants. Results are discussed in terms of implications for practitioners, satiation, habituation, and behavioral contrast. [ABSTRACT FROM AUTHOR]

The role of satiation as a determinant of restaurant patronage has been the subject of increasing research attention. The purpose of this research is to further consider the relationship between satiation and switching behavior in the restaurant industry. Specifically, we seek to address the mediating mechanism of service quality in this framework. Based on the related tenets of diminishing marginal utility and hedonic adaptation, we propose that satiation and service quality are inversely related. The results of an empirical analysis confirm that as consumers become satiated with food, atmosphere, and restaurant service, perceptions of these three facets of overall service quality are diminished, leading to decreased satisfaction and switching intentions. In addition to the practical implications of these results, the finding that satiation directly impacts service quality represents an important step in the overall task of understanding the effects of satiation in determining restaurant patronage behavior. [ABSTRACT FROM AUTHOR]

Eating slowly is associated with a lower body mass index. However, the underlying mechanism is poorly understood. Here, our objective was to determine whether eating a meal at a slow rate improves episodic memory for the meal and promotes satiety. Participants ( N = 40) consumed a 400 ml portion of tomato soup at either a fast (1.97 ml/s) or a slow (0.50 ml/s) rate. Appetite ratings were elicited at baseline and at the end of the meal (satiation). Satiety was assessed using; i) an ad libitum biscuit ‘taste test’ (3 h after the meal) and ii) appetite ratings (collected 2 h after the meal and after the ad libitum snack). Finally, to evaluate episodic memory for the meal, participants self-served the volume of soup that they believed they had consumed earlier (portion size memory) and completed a rating of memory ‘vividness’. Participants who consumed the soup slowly reported a greater increase in fullness, both at the end of the meal and during the inter-meal interval. However, we found little effect of eating rate on subsequent ad libitum snack intake. Importantly, after 3 h, participants who ate the soup slowly remembered eating a larger portion. These findings show that eating slowly promotes self-reported satiation and satiety. For the first time, they also suggest that eating rate influences portion size memory. However, eating slowly did not affect ratings of memory vividness and we found little evidence for a relationship between episodic memory and satiety. Therefore, we are unable to conclude that episodic memory mediates effects of eating rate on satiety. [ABSTRACT FROM AUTHOR]

Background Early clinical studies showed the commercial lipid emulsion Fabuless™ to decrease energy intake (EI) and prevent weight regain, but later studies have failed to confirm this finding. Where appetite suppression has been observed it is commonly attributed to the ileal brake, where emulsified fats pass undigested to the distal small intestine and promote later satiety, but satiety profiles suggest possible transient effects within 15 min. The aim of this study was to determine whether this emulsion promotes short-term satiation and meal termination. Methods In a randomised cross-over intervention 18 lean men were given 4 lipid preloads immediately prior to a breakfast meal, during which ad libitum food consumption, time to meal termination and VAS-rated appetite scores were measured. Preloads were given as lipid emulsion and lipid control, both alone as a ‘shot’ and combined with a dairy yoghurt: (i) lipid emulsion alone (LE, Fabuless™ 4.2g lipid, 0.2 MJ), (ii) lipid control alone (LC, 4 .2g lipid, 0.2 MJ), (iii) LE + yoghurt (1.2 MJ), (iv) LC + yoghurt (1.2 MJ). Results Whilst both yoghurt preloads suppressed EI at breakfast relative to the ‘shots’, as expected, neither lipid emulsion suppressed EI or triggered more rapid meal termination when compared to energy matched lipid controls (P > 0.05). There was also no difference in VAS-assessed appetite scores between emulsion and control, for either preload. Conclusions When consumed with a meal there was no evidence in lean men that this commercial lipid emulsion promotes satiation or suppresses short-term food intake. [ABSTRACT FROM AUTHOR]

After lying on a slanted floor for a while with the eyes closed, we may perceive it to be less slanted than at the beginning. After viewing a slanted floor while lying on a flat base, we may perceive it to be more horizontal. We investigated these postural and visual adaptations and their interactions with participants lying and sitting on the floor. The participants were adapted to a floor that was posturally, visually, or jointly slanted, and were asked to estimate the test slants around the adapting slant. The estimates were described as a linear function of the test slant with a high goodness-of-fit over the adapting slant. This supported normalization, not satiation, view. Second, the slope of the function, i.e., sensitivity to slant, in the lying position was low in the postural and visual conditions but high in the joint condition, whereas the sensitivity in the sitting position was equally high in all conditions. This was explained by an increase in visual and non-visual cues to the gravitational vertical in the sitting position, and by an abnormal pattern of intracorporeal hydrostatic pressure in the lying position. Third, in both body positions, the angle at which the slant appeared horizontal, i.e., the subjective horizontal (SH), was larger in the postural condition than in the visual condition. Finally, when the postural and visual adaptations were joint, the SH in the lying position was somewhere between the postural- and visual-alone SHs, whereas the SH in the sitting position approximated the visual-alone SH. [ABSTRACT FROM AUTHOR]

Background: The relation between hunger, satiation, and integrated gastrointestinal motility and hormonal responses in morbidly obese patients after sleeve gastrectomy has not been determined. Objective: The objective was to assess the effects of sleeve gastrectomy on hunger, satiation, gastric and gallbladder motility, and gastrointestinal hormone response after a liquid meal test. Design: Three groups were studied: morbidly obese patients (n = 16), morbidly obese patients who had had sleeve gastrectomy (n = 8), and nonobese patients (n = 16). The participants fasted for 10 h and then consumed a 200-mL liquid meal (400 kcal + 1.5 g paracetamol). Fasting and postprandial hunger, satiation, hormone concentrations, and gastric and gallbladder emptying were measured several times over 4 h. Results: No differences were observed in hunger and satiation curves between morbidly obese and nonobese groups; however, sleeve gastrectomy patients were less hungry and more satiated than the other groups. Antrum area during fasting in morbidly obese patients was statistically significant larger than in the nonobese and sleeve gastrectomy groups. Gastric emptying was accelerated in the sleeve gastrectomy group compared with the other 2 groups (which had very similar results). Gallbladder emptying was similar in the 3 groups. Sleeve gastrectomy patients showed the lowest ghrelin concentrations and higher early postprandial cholecystokinin and glucagon-like peptide 1 peaks than did the other participants. This group also showed an improved insulin resistance pattern compared with morbidly obese patients. Conclusions: Sleeve gastrectomy seems to be associated with profound changes in gastrointestinal physiology that contribute to reducing hunger and increasing sensations of satiation. These changes include accelerated gastric emptying, enhanced postprandial cholecystokinin and glucagon-like peptide 1 concentrations, and reduced ghrelin release, which together may help patients lose weight and improve their glucose metabolism after surgery. This trial was registered at clinicaltrials.gov as NCT02414893. [ABSTRACT FROM AUTHOR]

Trichothecenes are toxic metabolites produced by fungi that constitute a worldwide hazard for agricultural production and both animal and human health. More than 40 countries have introduced regulations or guidelines for food and feed contamination levels of the most prevalent trichothecene, deoxynivalenol (DON), on the basis of its ability to cause growth suppression. With the development of analytical tools, evaluation of food contamination and exposure revealed that a significant proportion of the human population is chronically exposed to DON doses exceeding the provisional maximum tolerable daily dose. Accordingly, a better understanding of trichothecene impact on health is needed. Upon exposure to low or moderate doses, DON and other trichothecenes induce anorexia, vomiting and reduced weight gain. Several recent studies have addressed the mechanisms by which trichothecenes induce these symptoms and revealed a multifaceted action targeting gut, liver and brain and causing dysregulation in neuroendocrine signaling, immune responses, growth hormone axis, and central neurocircuitries involved in energy homeostasis. Newly identified trichothecene toxicosis biomarkers are just beginning to be exploited and already open up new questions on the potential harmful effects of chronic exposure to DON at apparently asymptomatic very low levels. This review summarizes our current understanding of the effects of DON and other trichothecenes on food intake and weight growth. [ABSTRACT FROM AUTHOR]

Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide input to the highly organized hypothalamic circuitry and vagal complex of nuclei to determine cessation of energy intake during meal ingestion, and the return of appetite and hunger after fasting. Understanding these mechanisms is key to the physiological control of feeding and the derangements that occur in obesity and their restoration with treatment (as shown by the effects of bariatric surgery). [ABSTRACT FROM AUTHOR]

Background: Neural responses to rewarding food cues are significantly different in the fed vs. fasted (> 8 h food-deprived) state. However, the effect of eating to satiety after a shorter (more natural) intermeal interval on neural responses to both rewarding and aversive cues has not been examined. Objective: With the use of a novel functional magnetic resonance imaging (fMRI) task, we investigated the effect of satiation on neural responses to both rewarding and aversive food tastes and pictures. Design: Sixteen healthy participants (8 men, 8 women) were scanned on 2 separate test days, before and after eating a meal to satiation or after not eating for 4 h (satiated vs. premeal). fMRI blood oxygen level-dependent (BOLD) signals to the sight and/or taste of the stimuli were recorded. Results: A whole-brain cluster-corrected analysis (P < 0.05) showed that satiation attenuated the BOLD response to both stimulus types in the ventromedial prefrontal cortex (vmPFC), orbitofrontal cortex, nucleus accumbens, hypothalamus, and insula but increased BOLD activity in the dorsolateral prefrontal cortex (dlPFC; local maxima corrected to P ≤ 0.001). A psychophysiological interaction analysis showed that the vmPFC was more highly connected to the dlPFC when individuals were exposed to food stimuli when satiated than when not satiated. Conclusions: These results suggest that natural satiation attenuates activity in reward-related brain regions and increases activity in the dlPFC, which may reflect a “top down” cognitive influence on satiation. This trial was registered at clinicaltrials.gov as NCT02298049. Am J Clin Nutr 2015;101:697-704. [ABSTRACT FROM AUTHOR]

Although decision making is a ubiquitous function, the understanding of its underlying mechanisms remains limited, particularly at the single-cell level. In this study, we used the decision not to feed that follows satiation in the marine mollusk Aplysia to examine the role of putative decision-making neuron B51 in this process. B51 is a neuron in the feeding neural circuit that exhibits decision-making characteristics in vitro , which bias the circuit toward producing the motor programs responsible for biting behavior. Once satiated, Aplysia decided not to bite for a prolonged period of time (≥24 h) when presented with a food stimulus that normally elicits feeding in non-satiated animals. Twenty-four hours after satiation, suppressed feeding was accompanied by a significant decrease of B51 excitability compared to the control group of unfed animals. No differences were measured in B51 resting membrane properties or synaptic input to B51 between the satiated and control groups. When B51 properties were measured at a time point in which feeding had recovered from the suppressive effects of satiation ( i.e. , 96 h after satiation), no difference in B51 excitability was observed between satiated and control groups. These findings indicate that B51 excitability changes in a manner that is coherent with the modifications in biting resulting from food satiation, thus implicating this neuron as a site of plasticity underlying the decision not to bite following food satiation in Aplysia . [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the ability of a portable near infrared (NIR) instrument to collect the spectra in vivo of different tissues in healthy individuals and to relate their spectral information with food and energy intake, satiation, and satiety data. In this study, a hand-held NIR instrument was used to collect the spectra of different human tissues (e.g. arm, ear, face, jaw and wrist) with partial least squares (PLS) regression used to relate the NIR data with food and energy intake, satiation, and satiety measured in healthy individuals. The coefficient of determination in cross-validation (R2 CV) and the standard error in cross validation (SECV) for the prediction of satiety ranged between 0.58 and 0.62 and 223.3–235.0 total area under the curve (AUC), respectively, depending on the tissue analysed. The PLS cross-validation models based on the NIR spectra collected in both the arm and face tissues gave the best prediction of food intake (R2 CV 0.47–0.51, SECV 110.8-115 g). No workable calibrations were developed for the prediction of satiation, which might be associated with the inherent complexity of this parameter as well as the experimental conditions used to collect the data (e.g. type of tissue analysed). These results demonstrated the potential ability of in vivo NIR spectroscopy to identify tissue differences associated with satiety and food intake in individuals. However, a wider variety of food types, diets, and human subjects (samples) are needed to develop robust relationships between the NIR spectra of a tissue with both satiety and food intake. [Display omitted] • The NIR spectra of tissues was related to food satiety and appetite. • Variation in the individual spectra of tissues was observed. • Tissue NIR fingerprint spectra has potential to monitor satiety and appetite. [ABSTRACT FROM AUTHOR]