Sensory-specific Satiety Research Articles

No evidence for goal priming or sensory specific satiety effects following exposure to ambient food odours

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.

Manipulations of the context-response relationship reduce the expression of response habits

Habitual instrumental behaviour is believed to rely on stimulus–response (S–R) associations. However, the method most commonly used to identify habitual behaviour, outcome devaluation, provides only indirect evidence of S-R control. Therefore, it is important to have a better understanding of the S-R association believed to underlie habitual responding. Under free-operant conditions, the context itself likely serves as at least part of the relevant stimuli in the association, and so modifications to the predictive power of the context should alter the expression of habits. The following experiments investigated how changes to the relationship between the training context and performance of the response, either by changing the context during testing or by exposing animals to the context alone, without the response lever present, impacted behavioural control during a devaluation test. We found evidence that the training context is important for the expression of habits; testing animals in a different context than where they were trained resulted in increased goal-directed control (Experiment 1). Furthermore, context alone exposure also increased goal-directed control with animals that received context alone exposure showing stronger devaluation effects, whether the context alone exposure happened on the last day of training (Experiment 2) or throughout training (Experiment 3). These findings are consistent with prior reports that the training context is important for the expression of habits and extends these findings by using sensory-specific satiety as a means for devaluation and by using context alone exposure to alter behavioural control.

The nature of training in flavor preference learning determines the underlying associative structure

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.

Food Texture Perception and Its Influence on Consumer Preferences

Abstract Purpose: The general purpose of this study was to evaluate food texture perception and its influence on consumer preferences. Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library. Findings: The findings reveal that there exists a contextual and methodological gap relating to food texture perception and its influence on consumer preferences. Preliminary empirical review revealed that that food texture plays a pivotal role in shaping consumer preferences and purchase decisions across various product categories. Through a review of empirical studies, it was found that texture preferences are influenced by sensory experiences, cultural norms, and individual differences. Cross-cultural variability in texture preferences was noted among Western, Asian, and Middle Eastern populations, highlighting the importance of considering cultural factors in product development. Furthermore, texture was found to elicit emotional responses during eating, with certain textures evoking positive emotions while others elicited negative ones. The practical implications of texture research were underscored, emphasizing its relevance for food manufacturers, marketers, and policymakers in developing products that align with consumer expectations and promoting healthier food choices. Unique Contribution to Theory, Practice and Policy: The Sensory-Specific Satiety theory, Elaboration Likelihood Model (ELM) and Schema theory may be used in anchoring future studies on food texture perception and its influence on consumer preferences. The study provided recommendations that contributed to theory, practice, and policy in the field of food science and consumer behavior. The study suggested further exploration of texture perception mechanisms, tailored product development strategies based on sensory evaluations, and sensory marketing approaches emphasizing texture cues. Additionally, it recommended integrating sensory considerations into food regulations, promoting consumer education on texture-related labeling, and investing in sensory research and innovation. These recommendations aimed to enhance understanding of texture perception, improve product development and marketing strategies, and inform policy initiatives to meet consumer preferences effectively.

High perceived stress is associated with decreased sensory-specific satiety in humans

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.

Variety and portion size combine to increase food intake at single-course and multi-course meals

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.

Sex-biased effects of outcome devaluation by sensory-specific satiety on Pavlovian-conditioned behavior.

Goal-directed behavior relies on accurate mental representations of the value of expected outcomes. Disruptions to this process are a central feature of several neuropsychiatric disorders, including addiction. Goal-directed behavior is most frequently studied using instrumental paradigms paired with outcome devaluation, but cue-evoked behaviors in Pavlovian settings can also be goal-directed and therefore sensitive to changes in outcome value. Emerging literature suggests that male and female rats may differ in the degree to which their Pavlovian-conditioned responses are goal-directed, but interpretation of these findings is complicated by the tendency of female and male rats to engage in distinct types of Pavlovian responses when trained with localizable cues. Here, we used outcome devaluation via sensory-specific satiety to assess the behavioral responses in male and female Long Evans rats trained to respond to an auditory CS (conditioned stimulus) in a Pavlovian-conditioning paradigm. We found that satiety-induced devaluation led to a decrease in behavioral responding to the reward-predictive CS, with males showing an effect on both port entry latency and probability and females showing an effect only on port entry probability. Overall, our results suggest that outcome devaluation affects Pavlovian-conditioned responses in both male and female rats, but that females may be less sensitive to outcome devaluation.

Neonatal overfeeding alters the functioning of the mesolimbic dopaminergic circuitry involving changes in DNA methylation and effects on feeding behavior

Mesolimbic dopaminergic circuit is essential for food reward and motivational behaviors and can contribute to weight gain and obesity. Litter reduction is a classical model for studying the effects of neonatal overfeeding and overweight. Litters of Wistar rats were reduced to 4 pups/dam for small litter (SL) and 10 pups/dam for normal litter at postnatal day (PND) 4. Immediately after performing the feeding behavior tests, the animals were sacrificed in PND21 and PND90. The ventral tegmental area (VTA), Nucleus Accumbens Core (NAcC) and Shell (NAcSh) were isolated from frozen brain sections using the Palkovits micropunch technique. RNA and DNA were extracted from these areas, gene expression was measured by RT-qPCR and DNA methylation levels were measured by MSRM-qPCR technique. SL-PND21 animals presented increased expression levels of Tyrosine Hydroxylase and Dopamine Receptor D2 in VTA, decreased expression levels of dopamine active transporter (DAT) in VTA, and higher expression levels of DAT in NAcC. On the other hand, SL-PND90 animals showed decreased expression levels of Dopamine Receptor D1 and higher expression of DAT in NAcSh. These animals also evidenced impaired sensory-specific satiety. In addition, altered promoter methylation was observed at weaning, and remained in adulthood. This work demonstrates that neonatal overfeeding induces disruptions in the mesolimbic dopaminergic circuitry and causes alterations in feeding behavior from weaning to adulthood, suggesting that the neonatal period is critical for the normal development of dopaminergic circuit that impact on feeding behavior.

Reduced liking and wanting for high-caloric foods: The transfer effect of sensory-specific satiety through repeated imagination

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.

Effects of flavour variety on the intake and palatability of commercial feed in nursery pigs.

Sensory-specific satiety (SSS) could negatively affect pigs' feed intake, even when diets satisfy their nutritional requirements. We evaluated the short-term effects of SSS on feed intake and palatability. Thirty-two nursery pigs (tested in pairs) were exposed to short-term feeding trials for 6 days. In Trial 1, animals received for 90 min over three consecutive days three feeders: with different flavours (VAR); the same flavour (MON); or a mixture of the three flavours (MIX) in a 3 × 3 Latin square design. In Trial 2, with the same animals and different flavours, the three feeders were delivered successively (1 feeder every 30 min). In Trial 1, there was a day-by-diet interaction (F 4,36 = 2.98; p = 0.032), where the VAR diet was least consumed on the first day but most consumed subsequently. In Trial 2 a triple interaction between diet, day and delivery order modified pig's intake (F 12,15 = 3.33; p = 0.015), and consumption patterns (F 12,15 = 3.52; p = 0.012); where VAR diet presented the highest values in the last delivery order on the third experimental day. Flavour variety may decrease the effect of SSS, increasing feed intake and hedonic value in nursery pigs when there was a previous experience with those flavours.

Switching between foods: A potential behavioral phenotype of hedonic hunger and increased obesity risk in children

ContextReward-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. Objectives1) 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. MethodsData 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. ResultsSwitching 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). ConclusionsFrequent 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.

Comparing the imagined consumption of sweet and savoury food on sensory-specific satiety

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.

Quantification of sensory specific satiety and desire to eat bitter or sweet-bitter infusions of yerba mate in women with normal weight

Among the beneficial properties of yerba mate, it has been proven that it produces a decrease in appetite, weight loss and a decrease in fat deposits. Sensory properties influence the palatability of food and ultimately influence the amount consumed. It is very frequent that infusions of mate alone or sweetened produce judgments of the type "I drink mate and I am satiated". The aim of this study was to quantify the specific sensory satiety (SSS) and the desire to eat (DE) of these infusions in females with normal body weight.Thirty female university students and professors participated, who reported their weight and height to determine the body mass index (BMI). To determine the SSS and DE, 1.2% W/V (MT) mate infusion was prepared, 5% W/V sweetened MT with sugar (MT-A) or Stevia rebaudiana B extract at 0.03% P /V (MT-B). In all cases, the infusions were prepared by placing the mate bag containing 3 g of sample in contact with 250 ml of water at 90 °C for 6 minutes. The infusions were consumed at 70°C. For the SSS and DE evaluations, crackers, vanilla-flavored light yogurt, and unsweetened corn flakes were presented as controls. The consumers evaluated in three sessions the perceived pleasure/desire to eat before and after consuming a 250 ml cup of each infusion and a 4 g portion of the controls using unstructured scales of 100 mm length. The SSS and the DE were calculated as the difference of the magnitudes of pleasure pre and post ingestion introducing the correction factor calculated from the respective magnitudes assigned to the controls. Data were analyzed using the General Linear Model and Tukey's test for post hoc contrasts to check for significant effects of reported SSS or DE for the three infusions. Referring to the BMI, all the women reported weights and heights that denote normal weight (average BMI = 20.9). The appearance of satiety occurs both in MT, MT-A and MT-B (average SSE = -11.8) and there is also a decrease in the desire to eat after mate overload (average DE = -13.5). It can be concluded that the SSS and the DE, which regulate the cessation of intake, are maintained even though the caloric density and the taste of these infusions change. It remains to find out if these mechanisms are down regulated due to the increase in body weight, which would cause a lack of satiety and the desire to eat this type of infusions.

Effects of Test Location and Sample Number on the Liking Ratings of Almond Beverage and Vegan Ramen Products.

The present study investigated the effects of the evaluation environment and sample number on liking ratings within the same testing session. It comprised two experiments that determined consumer taste ratings of the following food products: (1) almond beverage and (2) vegan ramen, as rated by 322 and 287 Korean consumers, respectively. Consumers tasted each food product under either laboratory or home-used test conditions. Additionally, three levels of sample numbers were established for evaluation (almond beverage test: 1, 2, and 4; vegan ramen test: 1, 3, and 5) in each test condition. A target sample was selected for each of the two food products to directly ascertain the effects of the evaluation environment and sample number on the liking ratings. The results revealed that during the same evaluation session, the sample number affected the liking ratings of the target sample more than the testing location. Moreover, the sample number effect was product item dependent, that is, no significant change was noted in the liking ratings of the target almond beverage sample according to sample number, whereas significant differences were observed in the liking ratings of the target vegan ramen sample. Furthermore, the sample number effect was more prominent under laboratory test conditions than under home-used test conditions probably due to the serving order effect driven by hedonic contrast, carry over effect, and sensory specific satiety. The findings demonstrate that home-used tests should be recommended over laboratory tests when measuring the liking of a small number of multiple sample food items with high flavor complexity.

Switching between bites of food and sips of water is related to food intake across meals varying in portion size

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.

Imagined eating – An investigation of priming and sensory-specific satiety

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.

Cocaine falls into oblivion during volitional initiation of choice trials.

When facing a choice, most animals quit drugs in favour of a variety of nondrug alternatives. We recently found, rather unexpectedly, that choice of the nondrug alternative is in fact inflexible and habitual. One possible contributing factor to habitual choice is the intermittency and uncontrollability of choice trials in previous studies. Here, we asked whether and to what extent volitional control over the occurrence of choice trials could change animals' preference by preventing habitual choice. To do so, rats were trained to nosepoke in a hole to trigger the presentation of two operant levers: one associated with cocaine, the other with saccharin. Rats were then free to choose among the two levers to obtain the corresponding reward, after which both levers retracted until rats self-initiated the next choice trial. Overall, we found that volitional control over choice trials did not change preference. Most rats preferred saccharin over cocaine and selected this option almost exclusively. Intriguingly, after repeated choice and consumption of saccharin, rats transiently lost interest in this option (i.e., due to sensory-specific satiety), but they did not switch to cocaine, preferring instead to pause during long periods of time before reinitiating a choice trial for saccharin. This finding suggests that during volitional initiation of a choice trial, rats fail to consider cocaine as an option. We discuss a possible associative mechanism to explain this perplexing behaviour.

Eating rate and bite size were related to food intake across meals varying in portion size: A randomized crossover trial in adults

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.

Sensory specific satiety or appetite? Investigating effects of retronasally-introduced aroma and taste cues on subsequent real-life snack intake

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.

Sensory-Specific Satiety Dissociates General and Specific Pavlovian-Instrumental Transfer.

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.