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Children in Australia and similar countries consume low amounts of vegetables. The present study investigated if children’s carrot consumption can be heightened by providing whole vs diced carrots in a real life setting. Children (n = 60, 25 males, ages 8.6 ± 1.6 yrs.) watched a 90-min movie on two different occasions, while randomly being served 1000 g of diced carrots on one occasion and whole carrots on the other occasion. Consumption, hunger and taste liking were measured at the start, 10 min and 90 min after the consumption period started. Overall, the consumption of whole carrots (median intake: 39 g after 10 min) was significantly higher (Z = −2.4, p = 0.02), than the consumption of diced carrots (median intake: 26 g after 10 min), and trended towards being higher after 90 min (median intake whole: 126 g, median intake diced: 66 g, z = −1.7, p = 0.08). The majority of children (67%) consumed more whole than diced carrots with the increase in consumption being on average 75% greater when carrots were presented whole as opposed to diced. Although liking of carrots was significantly correlated with consumption (diced: r = 0.63, p The present study suggests that serving carrots whole, rather than diced could be a promising strategy to increase children’s vegetable consumption in a snacking occasion.

This study investigated acute effects of coffee and caffeine consumption on reward value of coffee. Acutely caffeine abstinent, coffee consumers (n = 96, mean total daily caffeine intake 363 mg), evaluated coffee and water 5 and 50 minutes after consuming either decaffeinated coffee or water (single blind) with either 150 mg caffeine or placebo (double blind). Relative to water, coffee but not caffeine reduced reward value of coffee, as indexed by desire to consume coffee and the monetary value of coffee. Neither coffee nor caffeine consumption clearly affected the pleasantness of the taste of coffee (liking), or ad libitum coffee intake. As expected, caffeine increased alertness at the 50-minute timepoint. The effect of coffee consumption on coffee reward value is analogous to sensory-specific satiety demonstrated in studies on eating, but there was not an effect of caffeine analogous the post-ingestive inhibitory effect of food intake on food reward.

Background Reward sensitivity can generalize across domains, but evidence for generalization of suppressive reward-related stimulation is sparse, especially in the context of interoceptive nutrient-related stimuli. We hypothesized that subliminal fatty acid-induced gut-brain signals could attenuate sensitivity to exteroceptive rewards, not only within the food domain but also across domains. Method Intragastric infusion of 2.5 g lauric acid (fat condition) or saline (saline condition) was administered to 59 healthy heterosexual male volunteers in a blinded fashion. To assess whether the resulting interoceptive signals attenuate reward sensitivity within the food domain, participants rated the palatability of food images and performed a progressive ratio task. To assess whether such attenuation effect generalizes to the sexual and financial reward domains, participants rated attractiveness of female face images and performed an intertemporal monetary choice task. Results Participants' ratings of food images were lower (F1,172 = 4.51, p = 0.035, Cohen's d: -0.20) in the fat condition. The progressive ratio task terminated earlier in the fat condition compared to saline (F1,52 = 4.17, p = 0.046, odds ratio = 0.31, 95%CI [0.11, 0.98]). Participants' ratings of female face images did not differ between conditions (F1,172 = 1.85, p = 0.19, Cohen's d: -0.15). Moreover, the monetary discounting rate did not differ significantly between conditions. Conclusion Overall, these findings suggest a domain-specific effect of subliminal fatty acid infusion on decreasing reward sensitivity. ispartof: PHYSIOLOGY & BEHAVIOR vol:219 ispartof: location:United States status: published

Tempting environmental food cues and metabolic signals are important factors in appetite regulation. Food intake reduces liking of food cues that are congruent to the food eaten (sensory-specific satiety). With this study we aimed to assess effects of sensory-specific satiety on neural processing (perceptual and evaluative) of visual and olfactory food cues. Twenty healthy female subjects (age: 20 ± 2 years; BMI: 22 ± 2 kg/m2) participated in two separate test sessions during which they consumed an ad libitum amount of a sweet or savoury meal. Before and after consumption, event-related potentials were recorded in response to visual and olfactory cues signalling high-energy sweet, high-energy savoury, low-energy sweet and low-energy savoury food and non-food items. In general, we observed that food intake led to event-related potentials with an increased negative and decreased positive amplitudes for food, but also non-food cues. Changes were most pronounced in response to high-energy sweet food pictures after a sweet meal, and occurred in early processes of perception (~80–150 ms) and later processes of cognitive evaluation (~300–700 ms). Food intake appears to lead to general changes in neural processing that are related to motivated attention, and sensory-specific changes that reflect decreased positive valence of the stimuli and/or modulation of top-down cognitive control over processing of cues congruent to the food eaten to satiety.

Background There are consistent, evidence-based global public health recommendations to reduce intakes of free sugars. However, the corresponding evidence for recommending reduced exposure to sweetness is less clear. Objective Our aim was to identify and review the published evidence investigating the impact of dietary exposure to sweet-tasting foods or beverages on the subsequent generalized acceptance, preference, or choice of sweet foods and beverages in the diet. Design Systematic searches were conducted to identify all studies testing relations of variation in exposure to sweetness through foods and beverages with subsequent variation in the generalized acceptance, preference, or choice of sweetened foods or beverages, in humans aged >6 mo. Results Twenty-one studies met our inclusion criteria, comprising 7 population cohort studies involving 2320 children and 14 controlled trials involving 1113 individuals. These studies were heterogeneous in study design, population, exposure, and outcomes measured, and few were explicitly designed to address our research question. The findings from these were inconsistent. We found equivocal evidence from population cohort studies. The evidence from controlled studies suggests that a higher sweet taste exposure tends to lead to reduced preferences for sweetness in the shorter term, but very limited effects were found in the longer term. Conclusions A small and heterogeneous body of research currently has considered the impact of varying exposure to sweet taste on subsequent generalized sweet taste preferences, and this evidence is equivocal regarding the presence and possible direction of a relation. Future work should focus on adequately powered studies with well-characterized exposures of sufficient duration. This review was registered with PROSPERO as CRD42016051840, 24 November 2016.

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.

Sensory-specific satiety (SSS) describes a reduction in the pleasantness of the taste of (momentary liking) and desire to consume a food that occurs with eating, compared with the relative preservation of liking and desire for uneaten foods. We conducted three studies in healthy female and male participants to test whether SSS generalises from sweet drinks to sweet foods. Studies 1 (n = 40) and 2 (n = 64) used a two-condition cross-over design. Participants consumed non-carbonated, fruit squash drinks sweetened with low-calorie sweeteners (LCS) versus water and evaluated various food and drink samples (stimuli). Generalisation of SSS was evident across all sweet stimuli, without having an effect on non-sweet (savoury) stimuli. These SSS effects were present when measured shortly after consumption of the sweet drink, but not 2 h later. There was no evidence of a ‘rebound’ increase above baseline in liking or desire to consume sweet foods 2 h after the sweet drink versus water. In study 3, 51 participants consumed labelled and branded 500 ml cola and water drinks (4 conditions, cross-over design) immediately before and during ad libitum consumption of sweet and non-sweet snack foods. Compared with still water, ‘diet’ (LCS-sweetened) cola reduced sweet food intake, but not total ad libitum intake. Carbonated water decreased hunger and increased fullness compared with still water, without differentially affecting thirst. Energy compensation from the ad libitum snacks for consumption of sugar-containing cola averaged only 20%. Together, these results demonstrate that consumption of LCS drinks acutely decreases desire for sweet foods, which supports their use in place of sugar-sweetened drinks. Further studies on the effects of carbonation of appetite are warranted.

Attention-deficit/hyperactivity disorder (ADHD) is associated with neurobehavioral reward system dysfunctions that pose debilitating impairments in adaptive decision-making. A candidate mechanism for such anomalies in ADHD may be a compromise in the control of motivated behaviors. Thus, demonstrating and restoring potential motivational control irregularities may serve significant clinical benefit. The motivational control of action guides goal-directed behaviors that are driven by outcome value, and habits that are inflexibly cue-triggered. We examined whether ADHD symptomology within the general population is linked to habitual control, and whether a motivation-based manipulation can break well-learned habits. We obtained symptom severity scores from 106 participants and administered a Go/NoGo task that capitalizes on familiar, well-learned associations (green-Go and red-NoGo) to demonstrate outcome-insensitivity when compared to newly learned Go/NoGo associations. We tested for outcome-insensitive habits by changing the Go and NoGo contingencies, such that Go signals became NoGo signals and vice versa. We found that generally, participants responded less accurately when green and red stimuli were mapped to color-response contingencies that were incongruent with daily experiences, whereas novel Go/NoGo stimuli evoked similar accuracy regardless of color-response mappings. Thus, our Go/NoGo task successfully elicited outcome-insensitive habits (i.e., persistent responses to familiar stimuli without regard for consequences); however, this effect was independent of ADHD symptomology. Nevertheless, we found an association between hyperactivity and congruent Go response latency, suggesting heightened pre-potency to perform habitual Go actions as hyperactivity increases. To examine habit disruption, participants returned to the lab and underwent the familiar version of the Go/NoGo task, but were given mid-experiment performance tracking information and a monetary incentive prior to contingency change. We found that this motivational boost via dual feedback prevented the incongruency-related accuracy impairment, effectively breaking the habit, albeit independent of ADHD symptomology. Our findings present only a modest link between ADHD symptomology and motivational control, which may be due to compensatory mechanisms in ADHD driving goal-directed control, or our task’s potential insensitivity to individual differences in ADHD symptomology. Further investigations may be crucial for determining whether ADHD is related to motivational impairments.

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 vs 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. This article is protected by copyright. All rights reserved. [Abstract copyright: This article is protected by copyright. All rights reserved.]

Binge eating is characterized by the consumption of a large amount of palatable food in a short period of time and is a core feature of many eating disorders. Patients with eating disorders are also known to display impairments in inhibitory control, cognition and decision-making, which may promote and maintain binge eating symptomology. In the current study, we examined whether rats that were subsequently characterized as displaying a higher propensity to binge eat would show pre-existing deficits in reinforcer devaluation—a paradigm used to examine decision-making following reductions in the value of a food reinforcer. Female rats were first trained to respond on two levers for the delivery of two food reinforcers (sucrose and maltodextrin solutions). At the test stage, rats were provided 1 h access to one of the two reinforcers to allow for devaluation via sensory specific satiety, immediately followed by an extinction test with both levers. Normal rats typically show reductions in responding on the lever associated with the devalued reinforcer (i.e., intact goal-directed responding). Subsequently, we used intermittent access to palatable food to identify high (BE prone [BEP]; n = 14), intermediate (BE neutral [BEN]; n = 48), and low (BE resistant [BER]; n = 13) phenotypes of binge eating. Prior reinforcer devaluation performance showed BEN and BER rats suppressed responding on the lever associated with the devalued reinforcer while BEP rats did not. This insensitivity to instrumental reinforcer devaluation in BEP rats did not reflect impaired sensory-specific satiety as during a food choice test, BEP rats showed a more robust alteration in food preferences following devaluation. Additionally, across all rats sensory specific satiety was correlated with subsequent intake of palatable food. Collectively, these findings suggest dissociable effects of devaluation procedures on instrumental actions and consummatory behaviors in BEP rats, and may indicate that pre-existing differences in goal-directed behavior and sensory-specific satiety contribute to the propensity to overeat palatable food.

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.

International audience; Across the lifespan, eating is a common everyday act driven by the search for pleasure and reinforced by experienced pleasure. Pleasure is an innate indicator of the satisfaction of physiological needs, in addition to other attributes. Pleasure from eating is also learned and contributes to the development of children's eating habits, which remain mostly stable until adulthood. Based on classical models of determinants of food consumption behaviour, we identified three dimensions of pleasure from eating learned during childhood: 1/the sensory dimension, i.e., pleasure from sensory sensations during food consumption; 2/the interpersonal dimension, i.e., pleasure from the social context of food consumption; and 3/the psychosocial dimension, i.e., pleasure from cognitive representations of food. The objective of this narrative review is to explore whether these three dimensions may play a role in promotion of healthy eating behaviour among children. Up to now, it was assumed that providing nutritional information, pointing out which types of foods are "good" or "bad" for health, would drive healthier food choices in children. Today, we know that such strategies based on a cognitive approach toward eating have a limited impact on healthy choices and can even be counter-productive, leading children to avoid healthy foods. In the context of increasing rates of childhood obesity, new perspectives are needed to build efficient interventions that might help children adopt a healthy diet. This review suggests new directions for further research to test the efficacy of novel interventions that emphasize pleasure from eating.

Consumers’ satisfaction is important for the food industry to ensure product success. Determinants to food satisfaction are multifactorial and a method approaching the multiple determinants would provide a detailed picture of determinant behind consumers’ hedonic food appreciation. The aims of this study were (1) to develop a method that could give detailed information about sensory- and food satisfaction (2) to study differences in sensory satisfaction in a case study, and (3) to study the factors related to food satisfaction. Focus group interviews and a literature study provided an overview of factors with potential to affect food satisfaction. A total of four questionnaires, covering factors before-, during- and after intake as well as demographics, were developed to measure factors related to satisfaction. The questionnaires were utilised in a cross-over consumer study with 79 subjects consuming two sensory different variants of chicken soup. Soups were sensory evaluated utilising expert statements. The consumer study showed that sensory satisfaction was highly influenced by liking of taste and appearance, whereas liking of odour and texture influenced sensory satisfaction moderately. Food satisfaction was influenced by factors measured during- and post intake; sensory satisfaction, fulfilment of expectations, reason for ending intake, product performance relative to expectations, hunger and fullness after intake were found highly influential in food satisfaction. Pre-intake factors did not substantially influence food satisfaction. Though the use of multiple variables gave a detailed picture of factors involved in food satisfaction, there was still variation in food satisfaction that remained unaccounted.

Preliminary investigations reveal altered learning patterns in horses performing oral stereotypic behaviour which coincide with differential functioning of the basal ganglia group of brain structures. However, no studies to date have investigated similar differences in the equine locomotor stereotypy phenotype. The aim of this investigation was to employ behavioural probes shown previously to reveal basal ganglia dysfunction to initialise the neurologic studies of locomotor stereotypy and to compare cognitive and neural aspects of the locomotor and oral stereotypy phenotype. Spontaneous blink rate (SBR—number of full left eye-ball occlusions by the eye-lid in 30 min) and behavioural initiation rate (BIR- Behavioural transitions in 30 min) were conducted utilising a sample of crib-biting (n = 8), weaving (n = 8) and stereotypy free (n = 8) animals. Horses were observed within their home box for SBR and BIR, with this being repeated three times over three consecutive days. All horses then completed an extinction learning paradigm featuring sensory specific satiety to dissect appetitive and habitual response patterns. Animals were initially shaped to press an A4 sized conditioned stimulus (CS) card mounted on an operant device for a food reward (5 g pelleted feed). The extinction schedule was then split into two separate tasks. Task 1 required animals to conduct 20 operant responses (OR) followed by sensory devaluation (1 kg freely available feed), whilst Task 2 required 40 OR prior to the devaluation phase. Following reward devaluation horses were subjected to an extinction phase where responses to the CS card were not rewarded. Crib-biting horses demonstrated significantly lower SBR than control (p

It has been proposed that both positive and negative symptoms in schizophrenia (SZ) may derive, at least in part, from a disrupted ability to accurately and flexibly represent the value of stimuli and actions. To assess relationships between dimensions of psychopathology in SZ, and the tendency to devalue food stimuli, on which subjects were fed to satiety, we administered a sensory-specific satiety (SSS) paradigm to 42 SZ patients and 44 controls. In each of 2 sessions, subjects received 16 0.7-ml squirts of each of 2 rewarding foods and 32 squirts of a control solution, using syringes. In between the 2 sessions, each subject was instructed to drink one of the foods until he/she felt “full, but not uncomfortable.” At 10 regular intervals, interspersed throughout the 2 sessions, subjects rated each liquid for pleasantness, using a Likert-type scale. Mann-Whitney U-tests revealed group differences in SSS effects. Within-group tests revealed that, while controls showed an effect of satiety that was sensory specific, patients showed an effect of satiety that was not, devaluing the sated and unsated foods similarly. In SZ patients, we observed correlations between the magnitude of SSS effects and measures of both positive and negative symptoms. We argue that the ability to flexibly and rapidly update representations of the value of stimuli and actions figures critically in the ability of patients with psychotic illness to process salient events and adaptively engage in goal-directed behavior.

Taste and smell changes are common side effects during chemotherapy in cancer patient and may have an impact on food preferences, food intake and quality of life. However, these relations have hardly been studied systematically in specific cancer populations. The overall aim of this thesis was to assess how the sense of taste and smell change upon treatment with chemotherapy in breast cancer and oesophagogastric cancer patients, and to investigate their consequences in terms of food preferences, food intake and quality of life. To measure food preferences for both macronutrients and tastes, the Macronutrient and Taste Preference Ranking Task (MTPRT) was developed. in chapter 2, it was shown that by inducing sensory specific satiety for a standardized sweet and savoury meal, it is possible to detect shifts in preferences for both tastes and macronutrients with the MTPRT, and that these results are reproducible. In Chapter 3 we studied objective and subjective taste and smell perception and food preferences in advanced oesophagogastric cancer patients undergoing palliative chemotherapy. The result showed that only objective taste function decreases during chemotherapy, but other chemosensory measures were unchanged. A lower subjective taste perception was related to a lower preference for high-protein products. Therefore it is important to consider patients’ taste perception, when providing dietary advice to OGC patients Chapter 4 describes a study with similar outcome measures as chapter 3, but in breast cancer patients at several time points during and after chemotherapy, and compared to a healthy control group. The study showed that breast cancer patients like high-protein, high-fat, sweet and savoury products less during chemotherapy, thus showing altered preferences for macronutrients, but not for tastes. Furthermore, results showed a temporary decrease in taste and smell perception during chemotherapy. These findings show that patients should be informed prior to treatment on chemosensory changes, and that these changes should be monitored during treatment due to the consequences for nutritional intake and quality of life In chapter 5 we assessed the dietary intake of breast cancer patients before and during chemotherapy compared to a healthy control group, and associations with experienced symptoms during chemotherapy. It was shown that symptoms induced by chemotherapy were associated with lower total energy, protein and fat intake, which was manifested by a lower intake of specific food groups. Therefore, to ensure an optimal dietary intake during chemotherapy, it is important to monitor nutritional status and symptom burden during chemotherapy in breast cancer patients. To better understand the impact of chemosensory changes during chemotherapy on daily life, 13 advanced oesophagogastric cancer patients were interviewed (see chapter 6). Patients described a substantial impact of chemosensory and food-related changes on daily life (by changing daily routines), social life (eating being less sociable) and roles in the household (changing roles in cooking and grocery shopping). Finally, in chapter 7, we assessed the association between self-reported taste and smell perception and quality of life in breast cancer patients. A worse taste and smell perception was associated with a worse global quality of life, role, social and emotional functioning shortly after chemotherapy. In patients treated with trastuzumab, a worse taste and smell perception was still associated with quality of life, social and role functioning half a year after chemotherapy had ended. From the studies in this thesis we can conclude that chemotherapy mainly affects the sense of taste. The subjective perception of taste was associated with a lower preference for food products and lower energy intake. This indicates that it is not necessarily an actual change in the sense of taste or smell that has an impact on patients, but flavour perception as a whole and potentially a lower enjoyment of food. Moreover, these perceived changes in taste and smell can have a substantial impact on cancer patients’ lives, in a practical way by changing daily patterns of eating, but also socially and in roles in the household. A changed chemosensory perception during chemotherapy may lead to a worsened nutritional status, and could thereby negatively impact the response to chemotherapy. Therefore chemosensory perception should be monitored during chemotherapy. Future studies should further investigate the mechanisms behind chemosensory changes, factors that contribute to subjective taste perception and possible interventions to alleviate chemosensory changes during chemotherapy.

Children’s vegetable consumption is often lower than that needed to promote optimal health and development, and practical approaches for increasing vegetable consumption are needed. Sensory Specific Satiety (SSS) reduces the liking and consumption of a consumed food over the course of an eating occasion and is an important factor in meal termination. The present study aimed to investigate the development of SSS when children ate vegetables of different sizes. The absence of SSS would be an encouraging sign to provide children more vegetables during a meal. Seventy-two children (33 boys, ages 8.8 ± 1.5 years) were recruited from Australian primary schools. Participating children consumed either whole or diced carrots for a maximum period of 10-min from a 500 g box. Cucumber was used as a control vegetable. Children’s liking of carrots and cucumber was measured with a 5-point child friendly hedonic scale prior to and after carrot consumption. In comparison to cucumber, liking for neither diced (p = 0.57) nor whole carrots (p = 0.18) changed during ad libitum consumption of carrots, indicating that SSS did not occur. However, children (n = 36) who finished eating carrots within the 10-min time limit, spent more time eating the whole carrots compared to the diced carrots (p < 0.05), which tended to result in a higher consumption of whole carrots (p < 0.06). This suggests that, in order to increase vegetable consumption, it is better to present children whole carrots than diced carrots. These findings might aid in the development of strategies to promote children’s greater vegetable consumption.

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.

Among the key characteristics of the Western obesogenic food environment is a highly palatable and varied food supply. Laboratory investigations of eating behavior in both humans and animals established key roles for palatability and variety in stimulating appetite, delaying satiety, and promoting excessive energy intake. There is a robust effect of food palatability and variety on short-term food intake, and increased variety and palatability also cause weight gain in animal models. However, laboratory paradigms do not replicate the complexities of eating in a natural setting, and there is a shortage of evidence to estimate the magnitude of effects on weight in humans. There are substantial individual differences in susceptibility to the palatability effect and this may be a key determinant in individual vulnerability to weight gain. The understanding of pathways through which palatability and variety can affect eating is advancing, and epidemiologic and intervention studies are needed to translate laboratory findings into applications in public health or clinical domains, and to establish whether there is a role for greater regulation of the food environment in tackling increases in obesity.

Increased energy consumption, especially increased consumption of sweet energy-dense food, is thought to be one of the main contributors to the escalating rates in overweight individuals and obesity globally. The individual’s ability to detect or sense sweetness in the oral cavity is thought to be one of many factors influencing food acceptance, and therefore, taste may play an essential role in modulating food acceptance and/or energy intake. Emerging evidence now suggests that the sweet taste signaling mechanisms identified in the oral cavity also operate in the gastrointestinal system and may influence the development of satiety. Understanding the individual differences in detecting sweetness in both the oral and gastrointestinal system towards both caloric sugar and high intensity sweetener and the functional role of the sweet taste system may be important in understanding the reasons for excess energy intake. This review will summarize evidence of possible associations between the sweet taste mechanisms within the oral cavity, gastrointestinal tract and the brain systems towards both caloric sugar and high intensity sweetener and sweet taste function, which may influence satiation, satiety and, perhaps, predisposition to being overweight and obesity.

It is often claimed that colour (e.g., in a meal) affects consumption behaviour. However, just how strong is the evidence in support of this claim, and what are the underlying mechanisms? It has been shown that not only the colour itself, but also the variety and the arrangement of the differently-coloured components in a meal influence consumers' ratings of the pleasantness of a meal (across time) and, to a certain extent, might even affect their consumption behaviour as well. Typically, eating the same food constantly or repeatedly leads to a decrease in its perceived pleasantness, which, as a consequence, might lead to decreased intake of that food. However, variation within a meal (in one or several sensory attributes, or holistically) has been shown to slow down this process. In this review, we first briefly summarize the literature on how general variety in a meal influences these variables and the major theories that have been put forward by researchers to explain them. We then go on to evaluate the evidence of these effects based mainly on the colour of the food explaining the different processes that might affect colour-based sensory-specific satiety and, in more detail, consumption behaviour. In addition, we also discuss the overlap in the definitions of these terms and provide additional hypothesis as to why, in some cases, the opposite pattern of results has been observed.

The complex, interacting influences on eating behavior and energy expenditure prevent elucidation of the causal role of any single factor in the current obesity epidemic. However, greater variety in the food supply, particularly in the form of highly palatable, energy-dense foods, has likely made a contribution. This study was undertaken to test the hypothesis that greater dietary variety is associated with greater caloric intake within individual meals consumed by free-feeding, socially-housed female rhesus monkeys. Meal patterns were assessed during two, two-week dietary phases. One phase consisted of a choice between a standard chow diet and a highly palatable diet (HPD). The other phase consisted of access to the chow only. Food intake for each subject was recorded continuously using previously validated, automated feeders, and a meal was defined based on a minimum kilocalorie requirement and a minimum inter-meal interval. During the choice condition, animals electively consumed mixed meals that incorporated both diets as well as other meals that consisted exclusively of a single diet – chow-only or HPD-only. Animals consumed the most calories per meal when the meal was comprised of both the chow and HPD, which differed in caloric density, flavor, and texture. Interestingly, however, there was no significant difference in the amount of calories consumed as HPD-only meals in the choice condition compared to meals in the chow-only, no choice condition, suggesting consumption of a single food during a meal, regardless of palatability, provides a constant sensory experience that may lead to more rapid habituation and subsequent meal cessation. Additionally, during the dietary choice condition, animals consumed fewer calories in the form of chow-only meals. Thus, the present results suggest that limiting dietary variety, regardless of palatability, may be a useful strategy for weight loss in overweight and obese individuals by reducing caloric intake within individual meals.

The overall aim of this study was to explore long-term consumer acceptance of new environmentally sustainable alternatives to meat. We investigated whether meat substitutes, which are relatively new food products, would be better appreciated after repeated consumption. Eighty-nine non-vegetarian participants joined an in-home use test and consumed one type of product with their self-selected hot meal for 20 times during 10 weeks: Quorn (meat-like), tofu (not meat-like) or a meat reference (chicken filet). Initial liking (100-mm line scale) for chicken was higher (81 ± 19) than for Quorn (60 ± 28) and tofu (68 ± 21). On a product group level, boredom occurred with all three products and after 20 exposures there were no significant differences in product liking anymore. However, there were noticeably different individual responses within the three product groups, showing both ‘boredom’ and ‘mere exposure’ patterns. Mere exposure occurred significantly more frequent with tofu, with more than half of the participants showing an increased liking over time. We also found that meal patterns were related to boredom: bored persons used more different types of meals, probably to alleviate product boredom. This study demonstrates that liking of meat substitutes can be increased by repeated exposure for a segment of consumers. In addition, it indicates that the meal context should be considered in future in-home repeated exposure studies. Refereed/Peer-reviewed

Excessive eating is a major determinant of the present obesity epidemic. Early infancy is a critical period in food preference formation and habits established in this period track into adulthood. This behavior is learned though repeated experiences with foods. Many mechanisms influence children’s eating patterns and overall energy intake. In this review we focus on food preference formation, the food itself, and environmental factors related to the eating situation. We will highlight some of the many possible actions that are available to parents and practitioners to facilitate eating behavior supporting healthy diets in children. The plasticity of food preferences underlines the importance of parents’ and caregivers’ continuous efforts in helping children develop healthy eating patterns. It is never too late, but starting in early infancy holds many advantages.

What is the relationship between memory and appetite? We explored this question by examining preferences for recently consumed food in patients with amnesia. Although the patients were unable to remember having eaten, and were inclined to eat multiple meals, we found that sensory-specific satiety was intact in these patients. The data suggest that sensory-specific satiety can occur in the absence of explicit memory for having eaten and that impaired sensory-specific satiety does not underlie the phenomenon of multiple-meal eating in amnesia. Overeating in amnesia may be due to disruption of learned control by physiological aftereffects of a recent meal or to problems utilizing internal cues relating to nutritional state.

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.

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.

Flavor reflects taste, olfactory, and oral texture inputs, and can be influenced by the sight of food, and by cognitive descriptions and attention. This contribution shows how flavor is built by the appropriate combinations of these different sensory inputs and modulatory processes in the primate (including human) brain. Complementary neuronal recordings, 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. In the next cortical area, 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 in that they only respond to food when hungry, and in that activations correlate 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.

Complementary neuronal recordings and functional neuroimaging in human subjects 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 the orbitofrontal cortex (OFC), these sensory inputs are for some neurons combined by learning with olfactory and visual inputs, and these neurons encode food reward in that they only respond to food when hungry, and in that activations correlate with subjective pleasantness. Cognitive factors, including word-level descriptions, and attention modulate the representation of the reward value of food in the OFC and a region to which it projects, the anterior cingulate cortex. Further, there are individual differences in the representation of the reward value of food in the OFC. It is argued that over-eating and obesity are related in many cases to an increased reward value of the sensory inputs produced by foods, and their modulation by cognition and attention that over-ride existing satiety signals. It is proposed that control of all rather than one or several of these factors that influence food reward and eating may be important in the prevention and treatment of overeating and obesity.

Background The sensory attributes of foods may have an important influence on intake because of sensory-specific satiety (SSS). Foods with high SSS may aid in body weight maintenance as a result of termination of consumption before metabolic satiety. No studies have investigated whether long-term exposure to a food might change SSS or how this affects food intake. Objective The objective was to compare the effects of daily consumption of 3 energy-dense snack foods (hazelnuts, chocolate, and potato chips) for 12 wk on SSS and ad libitum intake during a tasting session. Design One hundred eighteen participants took part in this randomized, controlled, parallel study with 4 arms: control group (no additional food) or ∼1100 kJ/d for each snack. SSS, food intake, and body composition were measured at baseline and at week 12. Results Daily consumption of snacks for 12 wk resulted in a statistically significant reduction in SSS in all 3 snack groups (P = 0.015). However, no such changes were seen in the control group (P = 0.608). Ad libitum energy intake increased over the study during the tasting sessions for the snack food across all groups, including the control group (P = 0.039). Inverse associations were found between baseline SSS and BMI (P = 0.039), percentage body fat (P = 0.013), and fat mass (P = 0.004). Conclusion Habitual consumption of a high energy-dense snack food results in a decrease in SSS, which could lead to a higher energy intake of the snack. This trial was registered at www.anzctr.org.au as ACTRN12609000265279.

After food consumption, the motivation to eat (wanting) decreases and associated brain reward responses change. Wanting-related brain responses and how these are affected by consumption of specific foods are ill documented. Moreover, the predictive value of food-induced brain responses for subsequent consumption has not been assessed. We aimed to determine the effects of consumption of sweet and savory foods on taste activation in the brain and to assess how far taste activation can predict subsequent ad libitum intake. Fifteen healthy men (age: 27 +/- 2 y, BMI: 22.0 +/- 1.5 kg/m(2)) participated in a randomized crossover trial. After a >3-h fast, participants were scanned with the use of functional MR( before and after consumption of a sweet or savory preload (0.35 L fruit or tomato juice) on two occasions. After the scans, the preload juice was consumed ad libitum. During scanning, participants tasted the juices and rated their pleasantness. Striatal taste activation decreased after juice consumption, independent of pleasantness. Sweet and savory taste activation were not differentially affected by consumption. Anterior cingulate taste activation predicted subsequent ad libitum intake of sweet (r = -0.78; P

Taste is involved in food preference and choice, and it is thought that it can modulate appetite and food intake. The present study investigated the effect of savory or sweet taste on satiation, reward, and food intake and according to individual differences in eating behavior traits underlying susceptibility to overeating. In a crossover design, 30 women (BMI = 22.7 ± 2.3; age = 21.9 ± 2.6 y) consumed a fixed energy preload (360 kJ/g) with a savory, sweet, or bland taste before selecting and consuming items from a test meal ad libitum. Sensations of hunger were used to calculate the satiating efficiency of the preloads. A computerized task was used to examine effects on food reward (explicit liking and implicit wanting). The Three Factor Eating Questionnaire was used to compare individual differences in eating behavior traits. Satiation and total food intake did not differ according to preload taste, but there was an effect on explicit liking and food selection. The savory preload reduced liking and intake of high-fat savory foods compared to sweet or bland preloads. The eating behavior trait disinhibition interacted with preload taste to determine test meal intake. Higher scores were associated with increased food intake after the sweet preload compared to the savory preload. Independent of preload taste, disinhibition was associated with lower satiating efficiency of the preloads and enhanced implicit wanting for high-fat sweet food. Savory taste has a stronger modulating effect on food preference than sweet or bland taste and may help to preserve normal appetite regulation in people who are susceptible to overeating.

In the context of increasing prevalence of overweight and obesity in societies worldwide, enhancing the satiating capacity of foods may help people control their energy intake and weight. This requires an integrated approach between various food-related disciplines. By structuring this approach around the new product development process, this paper aims to present the contours of such an integrative approach by going through the current state of the art around satiety enhancing foods. It portrays actual food choice as the end result of a complex interaction between internal satiety signals, other food benefits, and environmental cues. Three interrelated routes to satiating enhancement are to change the food composition to develop stronger physiological satiation and satiety signals, anticipate and build on smart external stimuli at the moment of purchase and consumption, and improve palatability and acceptance of satiety enhanced foods. Key research challenges in achieving these routes in the field of nutrition, food technology, consumer, marketing, and communication are outlined.

The brain areas that represent taste also provide a representation of oral texture.Fat textureisrepresentedbyneuronsindependentlyof viscosity:someneuronsrespond to fat independently of viscosity, and other neurons encode viscosity. The neurons that respond to fat also respond to silicone and paraffin oil, indicating that the sensing is texture- not chemo-specific. This fat sensing is not related to free fatty acidssuchaslinoleicacid;afewotherneuronswithresponsestofreefattyacidstypically do not respond to fat in the mouth. Fat texture-sensitive neurons are found in theprimarytastecortex,thesecondarytastecortexintheorbitofrontalcortexwhere the pleasantness of food is represented, and in the amygdala. Different neurons respondtodifferentcombinationsof texture,taste,oraltemperature,andintheorbitofrontal cortex to olfactory and visual properties of food.Complementary human functional neuroimaging studies are described.

Liquids have been shown to have a low satiating efficiency. The may be related to the high rate of consumption for liquids which may be higher than 200 g/min. In a number of studies, we showed that the positive relationship between eating rate and energy intake is mediated by oro-sensory exposure time. Longer sensory exposure times are consistently associated with lower food intakes. This observation maybe linked to the role of cephalic phase responses to foods. Cephalic phase responses are a set of physiological responses, which are conceived to prepare the digestive system for the incoming flow of nutrients after ingestion, with the aim of maintaining homeostasis. Results from various studies suggest that cephalic phase responses are much smaller (absent) for liquids compared to solids. It is hypothesised that the absence of cephalic phase responses to liquid foods may be one of the causes why liquid energies enter the body undetected and lead to weak energy intake compensation. This idea fits with the concept of the taste system as a nutrient-sensing system that informs the brain and the gastro-intestinal system about what is coming into our body. With liquids, this system is bypassed. Slower eating may help the human body to associate the sensory signals from food with their metabolic consequences. Foods that are eaten quickly may impair this association, and may therefore lead to overconsumption of energy, and ultimately to weight gain.

Sensory-specific satiety, which is defined as a relative decrease in pleasantness, is increased by greater oro-sensory stimulation. Both sensory-specific satiety and pleasantness affect taste activation in the orbitofrontal cortex. In contrast, metabolic satiety, which results from energy intake, is expected to modulate taste activation in reward areas. The aim of this study was to determine the effects of the amount of oro-sensory stimulation and energy content on consumption-induced changes in taste activation. Ten men participated in a 2 × 2 randomized crossover study. Subjects were scanned twice using functional magnetic resonance imaging: after fasting for at least 2 h and after treatment, on four occasions. Treatment consisted of the ingestion of 450 mL of orangeade (sweetened with 10% sucrose or non-caloric sweeteners) at 150 mL/min, with either small (5 mL) or large (20 mL) sips. During scanning, subjects alternately tasted orangeade, milk and tomato juice and rated its pleasantness. Before and after the scans, subjects rated pleasantness, prospective consumption, desire to eat and sweetness for all tastants. Main findings were that, before treatment, the amygdala was activated more by non-caloric than by caloric orangeade. Caloric orangeade activated part of the striatum before, but not after treatment. We observed no main effects of sip size on taste activation and no interaction between sip size and caloric content. In conclusion, the brain responds differentially to caloric and non-caloric versions of a sweet drink and consumption of calories can modulate taste activation in the striatum. Further research is needed to confirm that the observed differences are due to caloric content and not to (subliminal) differences in the sensory profile. In addition, implications for the effectiveness of non-caloric sweeteners in decreasing energy intake need to be established

Odor stimuli play an important role in the perception of food flavor. Olfactory dysfunction is thus likely to affect eating behavior. In the present study, we hypothesized that dysfunctional olfactory perception promotes sensory-specific satiety, a decrease in pleasure derived from a certain test food during and shortly after its consumption relative to other unconsumed control foods. A total of 34 hyposmic/anosmic participants were compared with 29 normosmic control participants. All participants repeatedly consumed a fixed portion of one and the same food item, a procedure known to induce sensory satiation. We found evidence for sensory-specific satiety (SSS) regardless of olfactory function. It thus appears that olfactory deficits have no major effect on SSS.

The main objectives of our study were (1) to compare several direct and indirect measures of liking and wanting for food and thereby (2) investigating the transfer effect of sensory specific satiety (SSS) for sweet and savory taste to other foods. We used a cross-over design whereby 61 healthy, unrestrained subjects (19M/42F), with a mean age of 21.9 (SD 3.1) y and a mean BMI of 21.7 (SD 1.5) kg/m2 were offered a standardized amount of rice meal with either a sweet or savory taste. Afterwards, liking and wanting for 16 snack products, varying in taste (sweet/savory) and fat (high/low), were assessed. Method 1 assessed ad libitum intake, method 2 the willingness to work for access, and method 3 explicit and implicit responses to photographic food stimuli. All the methods used showed a similar pattern of results; after eating a preload with a certain taste, the liking and wanting of snacks with a similar taste were less than for snacks with a dissimilar taste. This transfer effect was not equipotent for sweet and savory tastes. It appears that in young, healthy adults, savory taste has a stronger modulating effect on subsequent food choice than sweet.

The ‘anorexia of aging’ refers to reduced appetite and energy intakes observed in some older adults. Satiation (the process that leads to the termination of eating, which may be accompanied by a feeling of satisfaction) and satiety (the feeling of fullness that persists after eating, potentially suppressing further energy intake until hunger returns) are important factors in the control of appetite and energy intake, and there is evidence that some aspects of satiation and satiety are altered in older adults. Factors affected include gastric emptying, which could affect satiation, and levels of gut hormones which could affect satiety. Sensory specific satiety also appears to be reduced in older subjects. This might be important in the anorexia of aging and dietary strategies could be used to reduce satiety and encourage an increased energy intake. However, many other factors may affect the anorexia of aging and it is important to understand these in order to help those at risk of malnutrition.

ll animals, but especially omnivores such as rats and humans, face the seemingly daunting task of selecting a diet that supplies all of the essential nutrients. The complexity of factors that can affect food selection was out­lined in a recent review which listed the follow­ing influences on the appetite for specific foods: metabolic influences (eg, caloric requirements, neurotransmitter levels, hor­mones); specific appetites (eg, NaCI when salt-deficient); disease states (eg, diabetes, cancer); pharmacological influences (eg, ano­rectic drugs); environmental influences (eg, temperature); social influences (eg, culture, re­ligion); learned preferences and aversions; and hedonic factors (eg, palatability, taste, tex­ture, odor).

Objective: To discover whether eating behaviour traits show continuity and stability over childhood.Subjects/Methods: Mothers of 428 twin children from the Twins Early Development Study participated in a study of eating and weight in 1999 when the children were 4 years old. Families were contacted again in 2006 when the children were aged 10 years, with complete data on 322 children; a response rate of 75%. At both times, mothers completed the Child Eating Behaviour Questionnaire (CEBQ) for each child. Continuity was assessed with correlations between scores at the two time points, and stability by changes in mean scores over time.Results: For all CEBQ subscales, correlations between the two time points were highly significant ( P-values

Complementary neurophysiological recordings in rhesus macaques (Macaca mulatta) and functional neuroimaging in human subjects show that the primary taste cortex in the rostral insula and adjoining frontal operculum provides separate and combined representations of the taste, temperature and texture (including viscosity and fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are for some neurons combined by learning with olfactory and visual inputs. Different neurons respond to different combinations, providing a rich representation of the sensory properties of food. In the orbitofrontal cortex feeding to satiety with one food decreases the responses of these neurons to that food, but not to other foods, showing that sensory-specific satiety is computed in the primate (including the human) orbitofrontal cortex. Consistently, activation of parts of the human orbitofrontal cortex correlates with subjective ratings of the pleasantness of the taste and smell of food. Cognitive factors, such as a word label presented with an odour, influence the pleasantness of the odour, and the activation produced by the odour in the orbitofrontal cortex. Food intake is thus controlled by building a multimodal representation of the sensory properties of food in the orbitofrontal cortex and gating this representation by satiety signals to produce a representation of the pleasantness or reward value of food that drives food intake. Factors that lead this system to become unbalanced and contribute to overeating and obesity are described.

Complementary neuronal recordings, 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 the orbitofrontal cortex (OFC), these sensory inputs are for some neurons combined by associative learning with olfactory and visual inputs, and these neurons encode food reward in that they only respond to food when hungry and in that activations correlate 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 OFC 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.

The effect of a repeated monotonous exposure on ad libitum intake, pleasantness and boredom in elderly people in a real life situation is unclear. We therefore investigated the effects of repeated exposure to ad libitum intake of three orange-based drinks on boredom and acceptance in young and elderly people. Young (n=32) and elderly women (n=36) participated in a randomized within subjects cross over trial with three intervention periods of 12 days each followed by a 2-day wash out period. During each intervention period, the participants received 1 L of one type of drink per day. The three drinks varied in sweetness intensity. Intake was measured by weighing the returned packets and pleasantness, boredom and sweetness were rated on a 10-point scale. For the young women, mean consumption of the three drinks (p

Television viewing (TVV) has been linked with obesity, possibly through increased sedentary behavior and/or through increased ingestion during TVV. The proposition that TVV causes increased feeding, however, has not been subjected to experimental verification until recently. Our objective was to determine if the amount eaten of two familiar, palatable, high-density foods (pizza and macaroni and cheese) was increased during a 30-min meal when watching TV. In a within-subjects design, one group of undergraduates (n = 10) ate pizza while watching a TV show of their choice for one session and when listening to a symphony during the other session. A second group of undergraduates (n = 10) ate macaroni and cheese (M&C). TVV increased caloric intake by 36% (one slice on average) for pizza and by 71% for M&C. Eating patterns also differed between conditions. Although the length of time to eat a slice of pizza remained stable between viewing conditions, the amount of time before starting another slice was shorter during TVV. In contrast, M&C was eaten at a faster rate and for a longer period of time during TVV. Thus, watching television increases the amount eaten of high-density, palatable, familiar foods and may constitute one vector contributing to the current obesity crisis.

Complementary neurophysiological recordings in macaques and functional neuroimaging in humans show that the primary taste cortex in the rostral insula and adjoining frontal operculum provides separate and combined representations of the taste, temperature and texture (including viscosity and fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are for some neurons combined by learning with olfactory and visual inputs. Different neurons respond to different combinations, providing a rich representation of the sensory properties of food. In the orbitofrontal cortex, feeding to satiety with one food decreases the responses of these neurons to that food, but not to other foods, showing that sensory-specific satiety is computed in the primate (including human) orbitofrontal cortex. Consistently, activation of parts of the human orbitofrontal cortex correlates with subjective ratings of the pleasantness of the taste and smell of food. Cognitive factors, such as a word label presented with an odour, influence the pleasantness of the odour and the activation produced by the odour in the orbitofrontal cortex. These findings provide a basis for understanding how what is in the mouth is represented by independent information channels in the brain; how the information from these channels is combined; and how and where the reward and subjective affective value of food is represented and is influenced by satiety signals. Activation of these representations in the orbitofrontal cortex may provide the goal for eating, and understanding them helps to provide a basis for understanding appetite and its disorders.