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Food managers face the dilemma of having to increase their product sales products without increasing risk for obesity. Here we posit that a strategy based on repeating front‐of‐package images of a flavor ingredient can help solve this dilemma. Prior literature reports positive benefits in terms of purchase from displaying one or more front‐of‐package flavor‐giving ingredient images but offers limited insights into the effect of repeating the same flavor‐giving ingredient image. Based on four experiments, we found a differential effect of flavor‐giving ingredient images repetition on consumption and purchase intention only when cognitive resources were available. The more flavor‐giving ingredient images, the lower product consumption (Study 1), but the easier mental flavor imagery, and the stronger purchase intention (Study 2). Specifically, the increase in flavor mental imagery produced by image repetition induces sensory‐specific satiety that drives more intention to purchase (Study 3). These findings are of interest for both reducing obesity due to overeating and designing front‐of‐package imagery. [ABSTRACT FROM AUTHOR]

Ubiquitous exposure to visual food content has been implicated in the development of obesity with both individual and societal costs. The development and increasing adoption of Extended Reality (XR) experiences, which deliver an unprecedented immersion in digital content, would seem to carry the risk of further exacerbating the consequences of visual food exposure on real-world eating behavior. However, some studies have also identified potentially health-promoting effects of exposure to visual food stimuli. One example is repeated imagined consumption, which has been demonstrated to decrease subsequent food consumption. This work contains the first comparison between imagined eating and actual eating, to investigate how the simulated activity fares against its real counterpart in terms of inducing satiation. Three-hundred participants took part in an experiment at a local food festival. The participants were randomized between three experimental conditions: imagined eating, actual eating, and control. Each condition consisted of thirty trials. Before and after the experimental manipulation, the participants recorded their eating desires and enjoyment of a piece of chocolate candy. The resulting data showed generally no difference between the imagined eating and control conditions, which stands in conflict with the prior literature. In contrast, the differences between imagined and actual eating were significant. These results may be explained by differences in the experimental tasks' dose–response relationships, as well as environmental-contextual disturbances. Overall, the findings do not corroborate the efficacy of imagined eating within a real-life context. [ABSTRACT FROM AUTHOR]

Sensory-specific satiety describes a decline in hedonic value of the taste of a food as it is consumed, relative to a non-consumed food - the pudding tummy phenomenon. Incentive motivation towards consumed foods has also been shown to decline. Interestingly, several studies report that brief exposure to food odours can also produce a sensory-specific satiety effect, in the absence of consumption, selectively reducing hedonic ratings and subsequent high calorie food choices. Yet, other studies report goal-priming effects of ambient odours, in which brief implicit exposure increases the hedonic value of odour congruent food options. The present study aimed to determine whether exposure to ambient food odours would enhance or reduce incentive motivation for associated foods. Participants completed either an ambient odour (N = 38) or food consumption (N = 40) task. In both, participants were randomly assigned to an indulgent (chocolate) or non-indulgent (orange) food group and completed two blocks of a cross-modality matching grip-force task. One block was completed immediately before, the other immediately after, odour exposure/food consumption. A grip-force transducer measured effort exerted "to win" briefly presented (33 or 200ms) visual images of these foods, relative to control stimuli. In both studies, participants exerted greater effort to win the food items than control images. While neither satiety nor priming effects were found following ambient odour exposure, a classic sensory-specific satiety effect was found in the food consumption study. That is, force exerted for chocolate images declined significantly following chocolate consumption, in the absence of any decline in motivation for orange stimuli. While differences in odour exposure findings could be explained by factors such as concentration, timing, and nature of exposure, questions remain about the robustness of previously reported odour induced satiety and priming effects., Competing Interests: Declaration of competing interest RH.‘s PhD studentship was partly funded by GlaxoSmithKline (G.S.K). G.S.K had no role in the design, analysis, or decision to publish this study., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Pairing a palatable flavor (US) with an initially neutral flavor cue (CS) results in an acquired conditioned preference for the latter. Two main associations have been proposed to explain the acquisition of flavor preferences: Flavor-Flavor and Flavor-Nutrient learning. Although the hedonic reaction triggered by US consumption has also been suggested as a possible additional component underlying acquired flavor preference, this issue has received little attention. Here we explored whether the amount of training to the CS-US compound can favor the formation of a Flavor-Hedonic reaction association using rats as subjects and sucrose as the US. We expected that the more exposure to the CS-US compound, the stronger the S-R type association. Since S-R associations are not sensitive to devaluation procedures, we used a Sensory-Specific Satiety procedure to devalue the US after conditioning and then measured preferences for the CS. On Experiment 1 with a short restrictive training (classic procedure), preference for the CS was decreased after devaluation of the US compared to the control condition. On Experiment 2, with short unrestrictive training, preference for the CS was again weakened. Experiment 3 with a long unrestrictive training, rats expressed preference for the CS regardless of the devaluation procedure. These results suggest that, as with an instrumental paradigm, extensive training in flavor preference learning undermines the US devaluation effect. • Pairing a flavor with sucrose results in a flavor conditioned preference. • The hedonic value of sucrose is devalued after its intake (Sensory-Specific Satiety). • After a short flavor-sucrose training, devaluing sucrose suppresses the conditioned preference. • Extended training to flavor-sucrose leads to a flavor preference that is insensitive to devaluation. [ABSTRACT FROM AUTHOR]

Pavlovian conditioning enables predictive stimuli to control action performance and action selection. The present experiments used sensory-specific satiety to examine the role of outcome value in these two forms of control. Experiment 1 employed a general Pavlovian-instrumental transfer design to show that a stimulus predicting a food outcome energizes the performance of an instrumental action earning another food outcome. This energizing effect was removed when the stimulus-predicted outcome or a novel outcome was devalued by sensory-specific satiety. Experiments 2 and 3 employed a specific Pavlovian-instrumental transfer design to demonstrate that a stimulus predicting a particular food outcome promotes the selection of an instrumental action earning the same, but not a different, food outcome. Remarkably, this effect was maintained when all or just one of the stimulus-predicted outcomes were devalued by sensory-specific satiety. These results indicate that satiety alone removes the expression of general PIT. By contrast, satiety or outcome-specific devaluation does not regulate the expression of specific PIT, which is insensitive to changes in outcome value. This dissociation is consistent with the view that general and specific PIT are two separate phenomena driven by distinct psychological mechanisms. [ABSTRACT FROM AUTHOR]

Pavlovian conditioning enables predictive stimuli to control action performance and action selection. The present experiments used sensory-specific satiety to examine the role of outcome value in these two forms of control. Experiment 1 employed a general Pavlovian-instrumental transfer design to show that a stimulus predicting a food outcome energizes the performance of an instrumental action earning another food outcome. This energizing effect was removed when the stimulus-predicted outcome or a novel outcome was devalued by sensory-specific satiety. Experiments 2 and 3 employed a specific Pavlovian-instrumental transfer design to demonstrate that a stimulus predicting a particular food outcome promotes the selection of an instrumental action earning the same, but not a different, food outcome. Remarkably, this effect was maintained when all or just one of the stimulus-predicted outcomes were devalued by sensory-specific satiety. These results indicate that satiety alone removes the expression of general PIT. By contrast, satiety or outcome-specific devaluation does not regulate the expression of specific PIT, which is insensitive to changes in outcome value. This dissociation is consistent with the view that general and specific PIT are two separate phenomena driven by distinct psychological mechanisms.

Ubiquitous exposure to visual food content has been implicated in the development of obesity with both individual and societal costs. The development and increasing adoption of Extended Reality (XR) experiences, which deliver an unprecedented immersion in digital content, would seem to carry the risk of further exacerbating the consequences of visual food exposure on real-world eating behavior. However, some studies have also identified potentially health-promoting effects of exposure to visual food stimuli. One example is repeated imagined consumption, which has been demonstrated to decrease subsequent food consumption. This work contains the first comparison between imagined eating and actual eating, to investigate how the simulated activity fares against its real counterpart in terms of inducing satiation. Three-hundred participants took part in an experiment at a local food festival. The participants were randomized between three experimental conditions: imagined eating, actual eating, and control. Each condition consisted of thirty trials. Before and after the experimental manipulation, the participants recorded their eating desires and enjoyment of a piece of chocolate candy. The resulting data showed generally no difference between the imagined eating and control conditions, which stands in conflict with the prior literature. In contrast, the differences between imagined and actual eating were significant. These results may be explained by differences in the experimental tasks’ dose–response relationships, as well as environmental-contextual disturbances. Overall, the findings do not corroborate the efficacy of imagined eating within a real-life context.

• Individuals with higher perceived stress levels had lower sensory-specific satiety (SSS). • The olfactory-specific satiety did not differ between the high- and the low stress groups. • For all participants, interoceptive sensibility was positively associated with the magnitude of SSS. Previous studies have shown that chronic stress increases food intake. One possible mechanism may be due to altered sensory-specific satiety (SSS) among people with high level of chronic stress. In the current study, seventy-six participants were divided into either high-stress or low-stress groups according to their Perceived Stress Scale (PSS) scores. Participants were assigned to consume one of two foods (banana milk and corn soup) ad libitum until they felt comfortably satiated. Before and after eating, participants rated their liking and wanting for the flavor and the odor (via retronasal and orthonasal routes) of the eaten and uneaten foods. Individual interoceptive sensibility and eating behavior were measured using the Multidimensional Assessment of Interoceptive Awareness (MAIA) and Reasons Individuals Stop Eating Questionnaire (RISE-Q-15), respectively. Compared to the low-stress group, the high-stress group demonstrated blunted SSS to the whole food flavor. No significant difference was found for olfactory-specific satiety (retronasal or orthonasal) between the two groups. In addition, across the whole sample of participants, MAIA total score was positively associated with the magnitude of SSS (r = 0.29, p = 0.01). These results indicate that chronic perceived stress may play a role in the experience of reward during eating. [ABSTRACT FROM AUTHOR]

Oral texture is represented in the brain areas that represent taste, including the primary taste cortex, the orbitofrontal cortex, and the amygdala. Some neurons represent viscosity, and their responses correlate with the subjective thickness of a food. Other neurons represent fat in the mouth, and represent it by its texture not by its chemical composition, in that they also respond to paraffin oil and silicone in the mouth. The discovery has been made that these fat‐responsive neurons encode the coefficient of sliding friction and not viscosity, and this opens the way for the development of new foods with the pleasant mouth feel of fat and with health‐promoting designed nutritional properties. A few other neurons respond to free fatty acids (such as linoleic acid), do not respond to fat in the mouth, and may contribute to some "off" tastes in the mouth. Some other neurons code for astringency. Others neurons respond to other aspects of texture such as the crisp fresh texture of a slice of apple versus the same apple after blending. Different neurons respond to different combinations of these texture properties, oral temperature, taste, and in the orbitofrontal cortex to olfactory and visual properties of food. In the orbitofrontal cortex, the pleasantness and reward value of the food is represented, but the primary taste cortex represents taste and texture independently of value. These discoveries were made in macaques that have similar cortical brain areas for taste and texture processing as humans, and complementary human functional neuroimaging studies are described. [ABSTRACT FROM AUTHOR]

Increases in food variety and portion size independently promote intake. Little is known about how these effects combine or how they depend on meal structure. In two randomized crossover experiments, once a week for four weeks, women ate a lunch meal that was varied in two properties: variety (low: three bowls of the favorite dish vs. high: three bowls, each with a different main dish) and portion size (small: 450 g vs. large: 600 g). In Experiment 1 (n = 42), dishes were served simultaneously and in Experiment 2 (n = 49), dishes were served sequentially over three courses. At each meal, the primary outcome of food intake was measured; additionally, we measured sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten). In Experiment 1 (simultaneous structure) variety and portion size did not interact (p = 0.72) but both independently increased intake; participants consumed 15 ± 7 g more at meals with high variety compared to low and 57 ± 7 g more from large portions compared to small (both p < 0.03). Similarly, in Experiment 2 (sequential structure) variety and portion size did not interact (p = 0.99) but participants consumed 30 ± 8 g more at high-variety meals and 51 ± 8 g more from large portions (both p < 0.001). SSS was not influenced by portion size in either experiment (both p > 0.16) or by variety in Experiment 1 (p = 0.58), but SSS was smaller at high-variety meals in Experiment 2 (p = 0.001). Thus, variety and large portions promoted greater food intake for a similar or smaller hedonic decline, indicating these effects were facilitated by delayed SSS. At meals with either a simultaneous or sequential structure, high variety and large portions combined to increase intake, suggesting that these common properties act together to promote overconsumption. [ABSTRACT FROM AUTHOR]

• Food switching is defined by how frequently one alternates between foods at a meal. • Greater food switching is associated with increased EAH intake in children. • Food switching may increase intake via delayed sensory-specific satiation. • Food switching mediates the association between reward-based eating and EAH. • Reward-based eating interacts with switching to confer increased obesity risk. Reward-based eating is a trait that increases risk for eating in the absence of hunger (EAH) and obesity. Eating behaviors such as switching more frequently between different foods may increase intake during EAH by delaying the onset of sensory-specific satiation (SSS); however, this question has not been empirically tested. 1) Test whether switching between foods mediates the relationship between reward-based eating and EAH intake. 2) Test whether switching between foods during EAH moderates the relationship between reward-based eating and weight status. Data were analyzed from a study assessing decision-making in children (n = 63 children; 9.4 ± 1.4 years, 77.0 ± 22.4 BMI%tile). Reward-based eating was quantified using the Children's Eating Behaviour Questionnaire. EAH was assessed as the amount of palatable food consumed following ad libitum consumption of a standard meal. Videos of eating behavior were coded for eating time, number of different foods consumed, and food switches. Ordinary least squares regressions were conducted to test hypotheses. Switching was positively associated with EAH intake for both kcal (p < 0.01) and grams (p < 0.01) such that each additional switch was associated with an increased intake of 17.0 kcal or 3.5 gs. Switching mediated the relationship between reward-based eating and EAH (p < 0.01) such that more frequent switching fully accounted for the positive association between reward-based eating and EAH (ps < 0.01). While reward-based eating was also positively associated with weight status (p < 0.01), this association was moderated by food switching (p < 0.01) such that the relationship was stronger for children who switch more frequently (p < 0.01). Frequent switching between foods was positively associated with EAH intake and mediated the relationship between reward-based eating and EAH. Moreover, reward-based eating was more strongly related to weight status in children who switched more frequently. Thus, food switching may contribute to overconsumption and be an important behavioral indicator of increased obesity risk in children. Studies across multiple meals and contexts will help determine if switching is a reliable behavioral phenotype. [ABSTRACT FROM AUTHOR]

• Tested the liking of and wanting for foods after participants' repeated imagination. • Sensory-specific satiety occurred after repeated imagination of consuming foods. • Sensory-specific satiety to a certain high-caloric food transferred to other high-caloric foods. • Imagined consumption may be an effective strategy to nudge healthy eating behaviors. Numerous studies have demonstrated that repeatedly consuming a specific food item within a short period of time can reduce individuals' liking of and wanting for this food. This phenomenon is referred to as sensory-specific satiety. Recent research has shown that sensory-specific satiety can also be elicited by repeated imagined consumption. The present study was conducted to examine whether repeated imagined consumption of one food could induce the transfer of sensory-specific satiety to other foods. In three experiments, the participants were instructed to repeatedly imagine consuming a high-caloric food 30 times and rate the extent to which they liked and desired other high- or low-caloric foods after imagining consumption 3 and 30 times. The results revealed a significant decrease in the liking of and wanting for the imagined food and other high-caloric foods they did not imagine consuming, whereas no such effects were observed for the unimagined low-caloric foods. These results suggest that repeated imagined consumption of a certain high-caloric food can also induce sensory-specific satiety to other high-caloric foods, thereby indicating the transfer of sensory-specific satiety based on repeated imagination without actual consumption. Our findings have implications in the practice of nudging strategies aimed at encouraging healthier eating behaviors by prompting individuals to repeatedly imagine consuming high-caloric foods prior to actual food consumption. [ABSTRACT FROM AUTHOR]

Highlights • An action that delivers an ingestible substance can become linked directly to postingestive sensations. • This linking accompanies chunking when the final action in the chunked series is consummatory. • A stimulus then evokes recall of the action and this evokes anticipation of the postingestive sensations. • This enables the rate of the action to be directly sensitive to the current motivational state. • It prevents the rate from being sensitive to either outcome devaluation or contingency degradation. Abstract In animal behavioral experiments, extended training causes instrumental actions that deliver ingestible substances to lose sensitivity to outcome devaluation and contingency degradation, and to gain direct sensitivity to the current motivational state. These features of habitual control have been attributed to a process that relies on stimulus-response (S-R) associations linking the context to instrumental actions and Pavlovian associations linking the same context to orally-sensed properties of substances attained there. This Pavlovian process was conceived based on the results of irrelevant incentive experiments, but it is not supported by the results of all such experiments. An alternative process is therefore proposed here. In this process, recall of the instrumental action is evoked by an S-R association, but the rate at which this action is then performed is controlled by anticipation of postingestive sensations that have frequently followed it. This anticipation relies on recall of an association linking the action directly to the postingestive sensations. This association is learned during the formation of a chunked action series that begins with the instrumental action and ends with a consummatory response. It enables a prediction of subjective value that is directly influenced by the current motivational state, but is not influenced by devaluation or non-contingent delivery of the substance that has produced the postingestive sensations. [ABSTRACT FROM AUTHOR]

We investigated the role of attention and eating simulation in satiety changes induced by repeated exposure to the visual appearance of food. Participants evaluated their subjective impressions of visually exposed and unexposed food before and after observing movies depicting food being removed from a dish. When participants attended to the food in the movie, changes in appetite from pre- to post-observation ratings were higher for unexposed than for exposed food. However, satiety changes were not observed when participants attended to letters superimposed onto the movie. Additionally, satiety did not change when the movie was played backward so that it did not simulate eating. The results showed the importance of attention in the satiety changes elicited by visual exposure to food. Furthermore, the results also suggest that the observation of visual images triggering the simulation of eating action may play an important role in the satiety changes induced by visual exposure to food. [ABSTRACT FROM AUTHOR]

• Repeated imagined consumption of savoury food change sensory-specific appetite. • Three repetitions increase, while thirty repetitions decrease appetite. • Satiation to sweet (vs. savoury) food is more taste-transferable. Repeated imagined consumption of food has become an intriguing and novel means to reduce, and thereby manage, appetite. However, it is thus far unknown how the sensory-specific satiation derived from imagined consumption transfers from food of one taste to another. This work presents two online studies (n = 748). The first study was a follow-up on a previous series of experiments on sweet food, now investigating sensory-specific appetite responses to savoury food. Participants were randomly assigned to imagine the consumption of depicted food items for either 3 or 30 trials, with appetite being assessed before and after the experimental manipulation. Akin to the previous experiments, savoury-specific appetite increased after 3 trials and showed no change (compared to baseline) after 30 trials. However, none of the two conditions had a statistically significant effect on general appetite. The second study compared the satiation transferability between 30 trials of imagined consumption of sweet to savoury food and vice versa. The data indicated that satiating on sweet food may transfer more readily to savoury food than the other way around. Collectively, these studies suggest that, in the context of imagined consumption, sweet and savoury food are equivalent in modulating the respective taste-specific appetites, while sweet food has a higher capacity to modulate general appetite as well as the appetite for food not consumed. [ABSTRACT FROM AUTHOR]

The influence of sweet taste sensitivity on food intake is not well understood. We investigated the involvement of salivary leptin and SNP of the sweet taste receptor genes (TAS1R2/TAS1R3) on sweet taste sensitivity, sensory-specific satiety (SSS) and macronutrient intake in healthy human adults. In all, nineteen high sweet sensitivity (HS) and eleven low sweet sensitivity (LS) subjects were classified based on the sweetness perception of one solution (9mM sucrose) forced-choice triangle test. All participants completed a randomised crossover design experiment where they consumed one of three iso-energetic soup preloads differing in primary taste quality (sweet, non-sweet taste-control or no-taste energy-control). A period of 1 h after the preload, participants were offered a buffet meal consisting of foods varying in taste (sweet or nonsweet) and fat content. Subjective measures included hunger/fullness and SSS for sweetness. Saliva and buccal cells were collected to measure leptin level and to study the TAS1R2/TAS1R3 specific SNP, respectively. Salivary leptin concentrations were significantly higher in LS than HS participants (P<0·05). In addition, HS showed stronger sweet SSS compared with LH participants (P <0·05), and consumed less carbohydrate (% energy) and more non-sweet foods than LS (P <0·01 and P<0·05, respectively). Alleles from each TAS1R2 locus (GG compared with AA alleles of rs12033832, and CT/CC compared with TT alleles of rs35874116) were related to higher consumption of carbohydrates (% energy) and higher amount of sweet foods, respectively (P <0·05). In contrast, no associations were found for the TAS1R3 alleles. These results contribute to understand the links between taste sensitivity, macronutrient appetite and food consumption. [ABSTRACT FROM AUTHOR]

The influence of binge-like feeding schedules on subsequent food-related behavior is not well understood. We investigated the effect of repeated cycles of restriction and refeeding on two food-related behaviors; goal-directed responding for a palatable food reward and sensory-specific satiety. Hungry rats were trained to perform two instrumental actions for two distinct food outcomes and were then subjected to repeated cycles of restricted and unrestricted access to their maintenance chow for 30-days or were maintained on food restriction. Goal-directed control was then assessed using specific satiety-induced outcome devaluation. Rats were given 1 h access to one of theoutcomes and were then immediately given a choice between the two actions. Rats maintained on restriction responded more for the valued than the devalued reward but rats with a history of restriction and refeeding failed to show this effect. Importantly, all rats showed sensory-specific satiety when offered a choice between the two foods, indicating that pre-feeding selectively reduced the value of the pre-fed food. By contrast, sensory-specific satiety was not observed in rats with a history of intermittent feeding when the foods were offered sequentially. These results indicate that, similar to calorically dense diets, intermittent feeding patterns can impair the performance of goal-directed actions as well as the ability to reject a pre-fed food when it is offered alone. [ABSTRACT FROM AUTHOR]

Sensory-specific satiety (SSS) is the temporary decreased pleasantness of a recently eaten food, which inhibits further eating. Evidence is currently mixed whether SSS is weaker in obese people, and whether such difference precedes or follows from the obese state. Animal models allow testing whether diet-induced obesity causes SSS impairment. Female rats (n = 24) were randomly assigned to an obesogenic high-fat, high-sugar choice diet or chow-only control. Tests of SSS involved pre-feeding a single palatable, distinctively-flavored food (cheese- or cocoa-flavored) prior to free choice between both foods. Rats were tested for short-term SSS (2 h pre-feeding immediately followed by 2 h choice) and long-term SSS (3 day pre-feeding prior to choice on day 4). In both short- and long-term tests rats exhibited SSS by shifting preference towards the food not recently eaten. SSS was not impaired in obese rats. On the contrary, in the long-term tests they showed stronger SSS than controls. This demonstrates that neither the obese state nor a history of excess energy consumption fundamentally causes impaired SSS in rats. The putative impaired SSS in obese people may instead reflect a specific predisposition, properties of the obesogenic diet, or history of restrictive dieting and bingeing. [ABSTRACT FROM AUTHOR]

Food preferences are for a large part determined by the macronutrient content and taste of foods, but may change depending on internal and external factors. Here, we discuss a newly developed food preference task, the Macronutrient and Taste Preference Ranking Task (MTPRT), in which participants rank groups of four food products according to how much they desire to eat the products. The MTPRT includes pictures of sweet and savory food products from four categories: high-carbohydrate, high-fat, high-protein and low-energy. A within-subjects study on sensory-specific satiety was conducted to assess the task’s reliability and validity. Sixty-nine healthy participants performed two test sessions that were at least one week apart. Participants ate either a sweet or a savory meal, which were similar in macronutrient content. Before and after eating the meal participants rated appetite and completed the MTPRT. In hungry state, preference scores for all food categories were significantly correlated between the two test sessions (all r > 0.68, all p < 0.001). Preference for sweet decreased after the sweet meal and increased after the savory meal. In addition, preference for protein decreased more after consuming the savory meal than it did after consuming the sweet meal. Preference for carbohydrate and fat decreased after meal consumption, regardless of taste. Preference for low-energy increased after meal consumption. These results show the MTPRT is a reliable and valid task for measuring food preferences. The MTPRT can be used for both hypothesis-driven and exploratory studies to examine the influence of different factors on changes in food preferences. [ABSTRACT FROM AUTHOR]

As a food is consumed, its perceived pleasantness declines compared to that of other foods. Although this phenomenon, referred to as sensory-specific satiety, is well-established by means of measuring food intake and pleasantness ratings, this study was aimed at gaining more insight into the mechanisms that underlie such cognitive output behavior using two measures used in (food) emotion research, namely Autonomic Nervous System (ANS) responses and facial expressions. Twenty-four healthy female participants visited four times in a hungry state, in which they received 4 different semi-liquid meals (2 sweet and 2 savory) delivered via a time-controlled pump leading to sensory-specific satiety. Before and after the meals they were presented with a sip of all four different test meals where ANS responses (heart rate, skin conductance and skin temperature) and facial expressions were recorded. As expected, pleasantness ratings showed a significant decrease after eating the same meal or a meal similar in taste (sweet or savory) (p < 0.001), and less decrease after eating a meal with a different taste. In general, consumption of the test meals resulted in increased heart rate, reduced skin conductance and skin temperature, as well as intensified anger and disgusted facial expressions (p < 0.05). In addition, skin conductance, skin temperature, sad and angry expressions also showed effects reflecting sensory-specific satiety. In conclusion, ANS responses and facial expressions indicate that sensory specific satiety of foods 1) not only reduces the food's pleasantness but also arousal and 2) are possibly mediated by changes in food emotions. [ABSTRACT FROM AUTHOR]

This study explores the motivational dimensions underlying food consumption in tourism, and to examine the effects of two food-related personality traits, namely food neophobia and variety-seeking, on these motivational dimensions. A tourist food consumption motivational scale was developed and seven motivational dimensions were identified: novelty and variety, authentic experience and prestige, interpersonal and culture, price/value and assurance, health concern, familiarity and eating habit, and sensory and contextual pleasure. Both food neophobia and variety-seeking were found to have significant effects on various motivational dimensions. The implications of the findings for practice and future research are discussed. [ABSTRACT FROM AUTHOR]

Individuals eat more when served more food, but little is known about how this portion size effect is moderated by meal-related characteristics, particularly the inclusion of water served as a beverage. Patterns of eating and drinking as well as consumption of water could affect satiation by modifying exposure to the sensory qualities of food. In a crossover design, 44 adults ate lunch in the laboratory once a week for 4 weeks and intake was measured. The meal was a pasta dish that was varied in portion size (400, 500, 600, or 700 g) plus 700 g of water. Meals were video-recorded to count bites and sips and the number of switches between them. Sensory-specific satiety (SSS) was evaluated as the relative decline in hedonic ratings of the pasta after consumption. Serving larger portions led to a curvilinear increase in food intake (p < 0.0001). Neither switching between bites and sips nor water intake moderated the portion size effect. Independent of portion served, across all meals switching more frequently was related to greater food consumption (5.7 ± 1.8 g more food consumed for each additional switch, p = 0.004). Greater water intake was also related to greater food intake across portions (1.1 ± 0.5 g more food consumed for each additional 10 g of water, p = 0.025), but this effect was not significant after accounting for switching (p = 0.38). The magnitude of SSS was unaffected by switching, suggesting that switching allowed greater food intake for a given hedonic decline. At a meal with a single food, intake was greater when larger portions were served and also when there was more switching between bites and sips. Switching between food and water may promote energy intake by attenuating the development of SSS. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Sensory properties of some foods may be of importance to energy consumption and thus the development and maintenance of childhood obesity. This study compares selected food related qualities in overweight and normal weight children. Ninety-two participants were included; 55 were overweight with a mean age of 11.6 years (range 6-18 years) and a mean BMI z-score of 2.71 (range 1.29-4.60). The 37 normal weight children had a mean age of 13.0 years (range 6-19 years) and a mean BMI z-score of 0.16 (range -1.71 to 1.24). All children completed a half-hour long meal test consisting of alternation between consumption of foods and answering of questionnaires. Compared to the normal weight, the overweight children displayed lower self-reported intake paces (χ2(2) = 6.3, p = 0.04), higher changes in liking for mozzarella (F(1,63) = 9.55, p = 0.003) and pretzels (F(1,87) = 5.27, p = 0.024), and declines in wanting for something fat, of which the normal weight children displayed an increase (F(1,83) = 4,10, p = 0.046). No differences were found for sensory-specific satiety, wanting for the main food yoghurt, hunger, or satiety. In conclusion, overweight children did not differ from normal weight children in terms of sensory-specific satiety, hunger, or satiety. However, overweight children had lower intake paces and appeared to differ from normal weight children regarding foods with a fatty taste. [ABSTRACT FROM AUTHOR]

Serving larger portions leads to increased food intake, but behavioral factors that influence the magnitude of this portion size effect have not been well characterized. We investigated whether measures of eating microstructure such as eating rate and bite size moderated the portion size effect. We also explored how sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten) was affected by eating microstructure and larger portions. In a randomized crossover design, 44 adults aged 18-68 y (66% women; 46% with overweight and obesity) ate lunch in the laboratory once a week for 4 weeks. The meal consisted of pasta that was varied in portion size (400, 500, 600, or 700 g) and 700 g of water. Meals were video-recorded to assess bite count and meal duration, which were used to calculate mean eating rate (g/min) and mean bite size (g/bite). At each meal participants also completed an assessment of SSS. The results showed that as larger portions were served, meal intake increased in a curvilinear manner (p < 0.0001). Measures of eating microstructure did not moderate the portion size effect but were related to intake across all portions; faster eating rate, larger bite size, higher bite count, and longer meal duration were associated with greater consumption at all meals (all p < 0.0001). SSS was not influenced by any measure of eating microstructure or by portion size (all p > 0.10). In summary, the portion size effect was not moderated by eating microstructure, but relatively faster eating rates and larger bite sizes at meals, along with large portions, combined to increase food intake. [ABSTRACT FROM AUTHOR]

I describe my 50 year career in ingestive behavior in the hope of inspiring young scientists to join in the excitement of discovering why animals, especially the human animal, eat and drink. My interest in ingestive behavior started by chance in a freshman biology class at the University of Pennsylvania taught by Alan Epstein. Once I was exposed to the thrill of doing research my plans for medical school were abandoned and I traveled to the University of Cambridge in England where with James Fitzsimons I completed a Ph.D. in physiology on studies of thirst in rats. After I moved on to the University of Oxford, the early training in biologic mechanisms provided a good basis for studies in humans. We characterized the sensations associated with thirst and the mechanisms involved in its initiation and termination. We also continued to work with animal models in a series of studies of dietary obesity. The effect of dietary variety on rat's intake led to studies of sensory-specific satiety in humans. In recent years the primary interest of my lab has been how food properties affect intake, satiety, and body weight. At the Johns Hopkins School of Medicine and now at The Pennsylvania State University, we have conducted systematic studies of the effects of the macronutrients, variety, portion size, and energy density in both adults and children. Currently our research aims to understand how to leverage the robust effects of variety, portion size, and energy density to encourage healthy eating and drinking. Throughout my career I have been lucky to have been in supportive environments surrounded by creative, insightful, and diligent colleagues. [ABSTRACT FROM AUTHOR]

Typically, the subjective pleasantness of an odor decreases after it has been repeatedly smelled. This study investigates how the pleasantness ("liking") and the wish to be further exposed to the same odor ("wanting") are affected by variety on a longer time scale, and how they relate to actual food intake. Twenty-five participants rated a coconut odor presented 120 times for its liking and wanting before being offered coconut sweets. The amount eaten was assessed. Individual patterns of change were described by fitting 3 different models to the ratings. To study effects of variety on odor evaluation, the ratings were compared with a previous study where coconut was 1 of 3 odors presented in an alternating way. Initially, both liking and wanting the odors were high, but decreased over repetitions in 75% of the subjects. About 40% of all subjects showed an exponential change of ratings, 40% a step-like change, and 20% a linear change. Food intake was not related to the pattern of change in the ratings. Moreover, decreased olfactory pleasure did not seem to affect eating behavior. However, participants who rated the coconut odor higher at the beginning ate twice as many sweets as the others. Odor variety did not affect the experienced pleasure of smelling (liking), but did affect the motivation to experience the same smell again (wanting). This has not been reported for food or touch stimulation and may be specific for the perception of odors. [ABSTRACT FROM AUTHOR]

Our olfactory sense plays an important role in eating behavior by modulating our food preferences and intake. However, hunger or satiety may also influence how we perceive odors. Albeit speculative, contradictory results found in the past may have resulted from confounding by type of meal that participants ate to induce satiety. We aimed to investigate the influence of hunger state on olfactory sensitivity, comparing hunger to satiety using 2 different types of lunch to control for sensory-specific satiety. Odor detection thresholds were measured in 2 groups of participants (39 per group, 18-40 years), under 3 conditions: when hungry (twice), after a sweet lunch, and after a savory lunch. One group had their detection thresholds tested for a sweet odor, whereas in the other group, sensitivity to a savory odor was measured. Differences in olfactory sensitivity conditions were analyzed using linear mixed models. Participants had higher scores on the odor sensitivity task in a hungry versus satiated state (P = 0.001). Within the satiated condition, there was no effect of type of lunch on odor sensitivity. In conclusion, hunger slightly enhances sensitivity to food odors, but did not significantly depend on the type of food participants ate, suggesting no clear influence of sensory-specific satiety. [ABSTRACT FROM AUTHOR]

• First study of aroma and taste sensory-specific effects on subsequent snack intake. • Breakfasts with high-intensity vanilla aroma and sweet taste led to less sweet, and more non-sweet snack intake. • Exposures to vanilla aroma and sweet taste did not affect the overall snack intake. • Sensory characteristics of a meal are important in driving subsequent snack choices. Exposure to sensory cues has been shown to profoundly affect sensory-specific appetite and satiety in empirical settings. The present study aims to understand whether taste and aroma, presented in a real food matrix, can elicit sensory-specific effects on subsequent snack consumption in real life. A total of 61 male participants (final N = 40; 21–39 years; 19.7–41.5 kg·m−2) undertook five breakfast sessions. In each session, participants were served oat puddings of customised, pre-determined portions, which was either plain (used as the control), or with added low or high intensity of vanilla aroma or non-caloric sweetness. Participants were asked to report pre- and post-meal satiety and meal pleasantness using a Satiety Labelled Intensity Magnitude (SLIM) and a hedonic Visual Analogue scale (VAS), respectively. Participants then recorded all-day food intake using standard Food Records, which enabled estimates of individual total, sweet , and non-sweet snack intake. Our results showed that breakfasts with high-intensity aroma or taste led to more significant reductions in hedonic VAS post-breakfast, as opposed to the control or low-intensity conditions (p < 0.05). The total snack intake was maintained at a similar level across the conditions (p > 0.05). Compared to the control or low-intensity conditions, breakfasts with high-intensity vanilla aroma or sweet taste were associated with increased sensory-incongruent (i.e., non-sweet) and decreased sensory-congruent (i.e., sweet) snack intake (non-sweet intake: aroma (F (2, 108) = 59.65, p < 0.001), taste (F (2, 108) = 43.74, p < 0.001); sweet intake: aroma (F (2, 108) = 6.93, p = 0.001), taste (F (2, 108) = 13.94, p < 0.001)). Overall, this study is the first to compare sensory-specific effects of retronasally-introduced aroma and taste on snack intake throughout the day, highlighting the important functional roles of sensory exposures in orientating food choices. [ABSTRACT FROM AUTHOR]

Complementary neuronal recordings in primates, and functional neuroimaging in humans, show that the primary taste cortex in the anterior insula provides separate and combined representations of the taste, temperature, and texture (including fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in a second tier of processing, in the orbitofrontal cortex, these sensory inputs are for some neurons combined by associative learning with olfactory and visual inputs, and these neurons encode food reward value on a continuous scale in that they only respond to food when hungry, and in that activations correlate linearly with subjective pleasantness. Cognitive factors, including word-level descriptions, and selective attention to affective value, modulate the representation of the reward value of taste and olfactory stimuli in the orbitofrontal cortex and a region to which it projects, the anterior cingulate cortex, a tertiary taste cortical area. The food reward representations formed in this way play an important role in the control of appetite, and food intake. Individual differences in these reward representations may contribute to obesity, and there are age-related differences in these value representations that shape the foods that people in different age groups find palatable. In a third tier of processing in medial prefrontal cortex area 10, decisions between stimuli of different reward value are taken, by attractor decision-making networks. [ABSTRACT FROM AUTHOR]

The sensory-affective attributes of beverages have an important influence on a given intake and successive consumptions because of sensory-specific satiety (SSS; defined as a decrease in pleasantness ratings of a food eaten relative to uneaten foods). No studies have, however, investigated how multiple sessions of SSS for familiar drinks over a period of several days up to a week may change their pleasantness and how these hedonic-related judgments are affected by the context during SSS testing. With twenty-six participants, the present study explored the medium lasting and contextual effects of repeated SSS sessions for a bitter-sweet infusion on olfactory and flavour pleasantness over the course of three exposures in either a laboratory or a cafeteria setting. The results showed olfactory and flavour SSS for the infusion following each consumption in both the artificial and the natural setting. More interestingly, despite the failure to detect medium-term SSS (i.e., a greater decrease in pleasantness ratings of a food eaten relative to uneaten foods after repeated SSS sessions over several days as compared to the first SSS session), a contextual modulation of olfactory SSS was observed with a lesser overall magnitude in the cafeteria compared to the laboratory setting. To the best of our knowledge, the impact of eating location on the development of satiation and the differential contextual sensitivity of SSS for orthonasal odours and flavours has not been reported previously. The implications of potential environmental control of SSS are considered in this study. [ABSTRACT FROM AUTHOR]

Ubiquitous exposure to visual food content has been implicated in the development of obesity with both individual and societal costs. The development and increasing adoption of Extended Reality (XR) experiences, which deliver an unprecedented immersion in digital content, would seem to carry the risk of further exacerbating the consequences of visual food exposure on real-world eating behavior. However, some studies have also identified potentially health-promoting effects of exposure to visual food stimuli. One example is repeated imagined consumption, which has been demonstrated to decrease subsequent food consumption. This work contains the first comparison between imagined eating and actual eating, to investigate how the simulated activity fares against its real counterpart in terms of inducing satiation. Three-hundred participants took part in an experiment at a local food festival. The participants were randomized between three experimental conditions: imagined eating, actual eating, and control. Each condition consisted of thirty trials. Before and after the experimental manipulation, the participants recorded their eating desires and enjoyment of a piece of chocolate candy. The resulting data showed generally no difference between the imagined eating and control conditions, which stands in conflict with the prior literature. In contrast, the differences between imagined and actual eating were significant. These results may be explained by differences in the experimental tasks' dose-response relationships, as well as environmental-contextual disturbances. Overall, the findings do not corroborate the efficacy of imagined eating within a real-life context.

A range of animal and human data demonstrates that excessive consumption of palatable food leads to neuroadaptive responses in brain circuits underlying reward. Unrestrained consumption of palatable food has been shown to increase the reinforcing value of food and weaken inhibitory control; however, whether it impacts upon the sensory representations of palatable solutions has not been formally tested.These experiments sought to determine whether exposure to a cafeteria diet consisting of palatable high fat foods impacts upon the ability of rats to learn about food-associated cues and the sensory properties of ingested foods. We found that rats fed a cafeteria diet for 2 weeks were impaired in the control of Pavlovian responding in accordance to the incentive value of palatable outcomes associated with auditory cues following devaluation by sensory-specific satiety. Sensoryspecific satiety is one mechanism by which a diet containing different foods increases ingestion relative to one lacking variety. Hence, choosing to consume greater quantities of a range of foods may contribute to the current prevalence of obesity. We observed that rats fed a cafeteria diet for 2 weeks showed impaired sensory-specific satiety following consumption of a high calorie solution.The deficit in expression of sensory-specific satiety was also present 1 week following the withdrawal of cafeteria foods. Thus, exposure to obesogenic diets may impact upon neurocircuitry involved in motivated control of behavior. [ABSTRACT FROM AUTHOR]

The results of three experiments reveal that memory for end enjoyment, rather than beginning enjoyment, of a pleasant gustatory experience determines how soon people desire to repeat that experience. We found that memory for end moments, when people are most satiated, interferes with memory for initial moments. Consequently, end moments are more influential than initial moments when people decide how long to wait until consuming a food again. The findings elucidate the role of memory in delay until repeated consumption, demonstrate how sensory-specific satiety and portion sizes influence future consumption, and suggest one process by which recency effects influence judgments and decisions based on past experiences. [ABSTRACT FROM PUBLISHER]

Abstract: We demonstrate in two studies that people get more satiated on a food after repeatedly rating or choosing among similar foods shown in pictures. Repeated evaluations of food apparently have an effect similar to actual consumption—decreased enjoyment of foods that share a similar taste characteristic (i.e., sensory-specific satiety). We provide mediation evidence to show that satiation manifests because considering a food engenders spontaneous simulations of the taste of that food item, which by itself is enough to produce satiation. These findings establish sensory simulations as an important mechanism underlying satiation, and provide behavioral evidence that simple evaluations can produce sensory-specific satiety. [Copyright &y& Elsevier]

Highlights: [•] We review the ways in which colour can affect pleasantness and consumption of food. [•] Several mechanisms account for colour variety reducing the decrease in pleasantness. [•] While colour variety can enhance selection, no increase on continuous intake has been evidenced. [•] Colour variety can enhance, but also suppress, motivation to eat. [ABSTRACT FROM AUTHOR]