Extrinsic Factors Underlying Food Valuation in the Human Brain

Does 'portion size' matter? Brain responses to food and non-food cues presented in varying amounts

Larger portions of food elicit greater intake than smaller portions of food, particularly when foods are high in energy density (kcal/g; ED). The neural mechanisms underlying this effect remain unclear. The present study used fMRI to assess brain activation to food (higher-ED, lower-ED) and non-food (office supplies) images presented in larger and smaller (i.e., age-appropriate) amounts in 61, 7-8-year-olds (29 male, 32 female) without obesity. Larger amounts of food increased activation in bilateral visual and right parahippocampal areas compared to smaller amounts; greater activation to food amount (larger > smaller) in this cluster was associated with smaller increases in food intake as portions increased. Activation to amount (larger > smaller) was stronger for food than office supplies in primary and secondary visual areas, but, for office supplies only, extended into bilateral parahippocampus, inferior parietal cortex, and additional visual areas (e.g., V7). Activation was greater for higher-vs. lower-ED food images in ventromedial prefrontal cortex for both larger and smaller amounts of food; however, this activation extended into left lateral orbital frontal cortex for smaller amounts only. Activation to food cues did not differ by familial risk for obesity. These results highlight potentially distinct neural pathways for encoding food energy content and quantity.

What's cooking, if not meat? Effects of repeated home-use, recipe inspiration and meal context on perception of plant-based meat analogues

Plant-based meat analogues (PBMA) may help consumers in shifting towards more plant-based diets, but PBMA are not widely used yet, and little is known about their longer-term acceptance. This study investigated whether consumer acceptance of PBMA changed with repeated home-use, and whether providing recipe suggestions in the form of meal boxes could influence PBMA acceptance. To this end, Dutch regular meat eaters (n = 61) prepared, consumed and evaluated two meals (one from a meal box, one self-created) with PBMA (PB mince and PB chicken, counterbalanced across meal types) per week at home for four weeks. As a secondary objective, potential longer-term effects of repeated home-use of PBMA on meat (analogue) consumption habits and attitudes (e.g. motives for choosing PBMA, attitudes toward eating less meat) were assessed in a pre-vs post-intervention survey. Responses were compared with a control group of consumers not participating in the home-use study (n = 179). Results provided no evidence that PBMA liking changed with repeated home-use, nor that the provision of meal boxes increased liking of PBMA. Instead, PBMA liking was strongly influenced by the meal context, which may have overruled potential effects of repeated exposure. Findings from the pre- vs. post-intervention survey suggest that repeated exposure may stimulate longer-term consumption of PBMA, although more seems needed to bring about a structural shift toward a less animal-based consumption pattern. Future research should investigate whether more sophisticated recipes that provide a suitable meal context for PBMA and elevate consumers' meal experiences may improve PBMA acceptance and facilitate the transition toward more sustainable diets.

Unveiling the Path to Resilience: Prioritizing Mental Health, Sleep, and Nutrition in the Post-COVID Era

The COVID-19 pandemic has disrupted daily life, impacting relationships, work, and education. This has led to increased stress, anxiety, and depression, along with altered sleep patterns and eating behaviors. Quarantine and isolation have worsened mental health, especially in children and the elderly, due to the loss of activities and physical contact. Sleep disorders and negative dreams perpetuate poor sleep quality, increasing the risk of health issues. Sedentary lifestyles and emotional effects contribute to unhealthy eating patterns and obesity, exacerbated by disrupted routines and limited outdoor activities. Addressing these challenges requires prioritizing mental health, promoting healthy sleep habits, and addressing obesity factors. The pandemic has profoundly affected human well-being, but resilience, mental health, sleep, and nutrition can enhance overall well-being and adaptability in the post-COVID era. This comprehensive opinion aims to raise awareness of the wide-ranging impacts of this pandemic on various aspects of human well-being and to emphasize the importance of implementing strategies that prioritize mental health, improve sleep habits, address eating behaviors, and foster resilience to navigate and thrive in the face of future challenges.

Neural mechanisms of expert persuasion on willingness to pay for sugar

Introduction: Sugar consumption is associated with many negative health consequences. It is, therefore, important to understand what can effectively influence individuals to consume less sugar. We recently showed that a healthy eating call by a health expert can significantly decrease the willingness to pay (WTP) for sugar-containing food. Here, we investigate which aspects of neural responses to the same healthy eating call can predict the efficacy of expert persuasion.

Methods: Forty-five healthy participants performed two blocks of a bidding task, in which they had to bid on sugar-containing, sugar-free and non-edible products, while their electroencephalography (EEG) was recorded. In between the two blocks, they listened to a healthy eating call by a nutritionist emphasizing the risks of sugar consumption.

Results: We found that after listening to the healthy eating call, participants significantly decreased their WTP for sugar-containing products. Moreover, a higher intersubject correlation of EEG (a measure of engagement) during listening to the healthy eating call resulted in a larger decrease in WTP for sugar-containing food. Whether or not a participant’s valuation of a product was highly influenced by the healthy eating call could also be predicted by spatiotemporal patterns of EEG responses to the healthy eating call, using a machine learning classification model. Finally, the healthy eating call increased the amplitude of the P300 component of the visual event-related potential in response to sugar-containing food.

Disussion: Overall, our results shed light on the neural basis of expert persuasion and demonstrate that EEG is a powerful tool to design and assess health-related advertisements before they are released to the public.

Hypothalamic interaction with reward-related regions during subjective evaluation of foods

The reward system implemented in the midbrain, ventral striatum, orbitofrontal cortex, and ventromedial prefrontal cortex evaluates and compares various types of rewards given to the organisms. It has been suggested that autonomic factors influence reward-related processing via the hypothalamus, but how the hypothalamus modulates the reward system remains elusive. In this functional magnetic resonance imaging study, the hypothalamus was parcellated into individual hypothalamic nuclei performing different autonomic functions using boundary mapping parcellation analyses. The effective interaction during subjective evaluation of foods in a reward task was then investigated between the human hypothalamic nuclei and the reward-related regions. We found significant brain activity decrease in the paraventricular nucleus (PVH) and lateral nucleus in the hypothalamus in food evaluation compared with monetary evaluation. A psychophysiological interaction analysis revealed dual interactions between the PVH and (1) midbrain region and (2) ventromedial prefrontal cortex, with the former correlated with the stronger tendency of participants toward food-seeking. A dynamic causal modeling analysis further revealed unidirectional interactions from the PVH to the midbrain and ventromedial prefrontal cortex. These results suggest that the PVH in the human hypothalamus interacts with the reward-related regions in the cerebral cortex via multiple pathways (i.e., the midbrain pathway and ventromedial prefrontal pathway) to evaluate rewards for subsequent decision-making.

"Expert persuasion" can decrease willingness to pay for sugar-containing food

Recent studies have revealed types of eating nudges that can steer consumers toward choosing healthier options. However, most of the previously studied interventions target individual decisions and are not directed to changing consumers’ underlying perception of unhealthy food. Here, we investigate how a healthy eating call—first-person narrative by a health expert—affects individuals’ willingness to pay (WTP) for sugar-free and sugar-containing food products. Participants performed two blocks of a bidding task, in which they had to bid on sweets labeled either as “sugar- free” or as “sugar-containing.” In-between the two blocks, half of the participants listened to a narrative by a dietary specialist emphasizing the health risks of sugar consumption, whereas the remaining participants listened to a control narrative irrelevant to food choices. We demonstrate that the health expert’s narrative decreased individuals’ WTP for sugar-containing food, but did not modulate their WTP for sugar- free food. Overall, our findings confirm that consumers may conform to healthy eating calls by rather devaluating unhealthy food products than by increasing the value of healthy ones. This paves the way for an avenue of innovative marketing strategies to support individuals in their food choices.

Dissecting ultra-processed foods and drinks: Do they have a potential to impact the brain?

Ultra-processed foods and drinks (UPF) are formulation of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes. They usually have a low nutrient but high energy density, with a high content of saturated and trans fats, and added sugars. In addition, they have characteristic organoleptic properties, and usually contain sophisticated additives, including artificial sweeteners, to intensify their sensory qualities and imitate the appearance of minimally processed foods. In addition, recent research has warned about the presence of chemicals (e.g., bisphenol) and neo-formed contaminants in these products. UPF production and consumption growth have been spectacular in the last decades, being specially consumed in children and adolescents. UPF features have been associated with a range of adverse health effects such as overeating, the promotion of inflammatory and oxidative stress processes, gut dysbiosis, and metabolic dysfunction including problems in glucose regulation. The evidence that these UPF-related adverse health effects may have on the neural network implicated in eating behavior are discussed, including the potential impact on serotonergic and dopaminergic neurotransmission, brain integrity and function. We end this review by placing UPF in the context of current food environments, by suggesting that an increased exposure to these products through different channels, such as marketing, may contribute to the automatic recruitment of the brain regions associated with food consumption and choice, with a detrimental effect on inhibitory-related prefrontal cortices. While further research is essential, preliminary evidence point to UPF consumption as a potential detrimental factor for brain health and eating behavior.

Insight into the Role of Psychological Factors in Oral Mucosa Diseases

With the development of psychology and medicine, more and more diseases have found their psychological origins and associations, especially ulceration and other mucosal injuries, within the digestive system. However, the association of psychological factors with lesions of the oral mucosa, including oral squamous cell carcinoma (OSCC), burning mouth syndrome (BMS), and recurrent aphthous stomatitis (RAS), have not been fully characterized. In this review, after introducing the association between psychological and nervous factors and diseases, we provide detailed descriptions of the psychology and nerve fibers involved in the pathology of OSCC, BMS, and RAS, pointing out the underlying mechanisms and suggesting the clinical indications.

Is It Worth It? Obesity Affects Snack Food Valuation Across the Menstrual Cycle

Background

The importance of menstrual cycle physiology in appetite and obesity is poorly understood. We investigated the effects of body mass index (BMI), menstrual cycle phase and sweet and salty taste on monetary valuation of snack foods.

Methods

We recruited 72 women and after the application of in- and exclusion criteria 31 participants with healthy weight and 25 with obesity remained. The participants completed a willingness to pay (WTP) task to measure subjective value of 30 snack food items in the pre-ovulatory and mid-luteal cycle phases.

Results

Generalized linear mixed model (GLMM) analysis revealed that BMI, cycle phase and snack taste interacted to influence WTP (−0.15 [−0.22, −0.03], p = 0.002). Hence, WTP was inversely related to BMI, but the strength of the relation depended on cycle phase and taste. The WTP of participants with healthy weight for salty taste changed across cycle phase but the WTP for sweet taste was not affected by cycle phase. Moreover, the cycle effect for the salty snacks ceased in participants with obesity.

Conclusion

The inverse effect of BMI on WTP valuation of snack foods contrasts with the positive effect of BMI on pleasantness ratings for milkshakes by the same women that we previously reported. This indicates that the two measures reflect different aspects of food-related valuative processing in obesity. Furthermore, the WTP data suggest that the selection of salty snacks may differ from that of sweet snacks in the pre-ovulatory phase of the menstrual cycle for individuals of healthy weight. The cycle phase does not seem to affect food valuation of participants with obesity. These findings are relevant to understanding and treating obesity in women.

“Sound” Decisions: The Combined Role of Ambient Noise and Cognitive Regulation on the Neurophysiology of Food Cravings

Our ability to evaluate long-term goals over immediate rewards is manifested in the brain’s decision circuit. Simplistically, it can be divided into a fast, impulsive, reward “system 1” and a slow, deliberate, control “system 2.” In a noisy eating environment, our cognitive resources may get depleted, potentially leading to cognitive overload, emotional arousal, and consequently more rash decisions, such as unhealthy food choices. Here, we investigated the combined impact of cognitive regulation and ambient noise on food cravings through neurophysiological activity. Thirty-seven participants were recruited for an adapted version of the Regulation of Craving (ROC) task. All participants underwent two sessions of the ROC task; once with soft ambient restaurant noise (∼50 dB) and once with loud ambient restaurant noise (∼70 dB), while data from electroencephalography (EEG), electrodermal activity (EDA), and self-reported craving were collected for all palatable food images presented in the task. The results indicated that thinking about future (“later”) consequences vs. immediate (“now”) sensations associated with the food decreased cravings, which were mediated by frontal EEG alpha power. Likewise, “later” trials also increased frontal alpha asymmetry (FAA) —an index for emotional motivation. Furthermore, loud (vs. soft) noise increased alpha, beta, and theta activity, but for theta activity, this was solely occurring during “later” trials. Similarly, EDA signal peak probability was also higher during loud noise. Collectively, our findings suggest that the presence of loud ambient noise in conjunction with prospective thinking can lead to the highest emotional arousal and cognitive load as measured by EDA and EEG, respectively, both of which are important in regulating cravings and decisions. Thus, exploring the combined effects of interoceptive regulation and exteroceptive cues on food-related decision-making could be methodologically advantageous in consumer neuroscience and entail theoretical, commercial, and managerial implications.

Evaluation of energy density and macronutrients after extremely brief time exposure

Many food decisions are made rapidly and without reflective processing. The ability to determine nutritional information accurately is a precursor of food decisions and is important for a healthy diet and weight management. However, little is known about the cognitive evaluation of food attributes based on visual information in relation to assessing nutritional content. We investigated the accuracy of visual encoding of nutritional information after brief and extended time exposures to food images. The following questions were addressed: (1) how accurately do people estimate energy and macronutrients after brief exposure to food images, and (2) how does estimation accuracy change with time exposure and the type of nutritional information? Participants were first asked to rate the energy density (calories) and macronutrient content (carbohydrates/fat/protein) of different sets of food images under three time conditions (97, 500 or 1000 ms) and then asked to perform the task with no time constraints. We calculated estimation accuracy by computing the correlations between estimated and actual nutritional information for each time exposure and compared estimation accuracy with respect to the type of nutritional information and the exposure time. The estimated and actual energy densities and individual macronutrient content were significantly correlated, even after a brief exposure time (97 ms). The degree of accuracy of the estimations did not differ with additional time exposure, suggesting that <100 ms was sufficient to predict the energy and macronutrients from food images. Additionally, carbohydrate estimates were less accurate than the estimates of other nutritional variables (proteins, fat and calories), regardless of the exposure time. These results revealed rapid and accurate assessment of food attributes based on visual information and the accuracy of visual encoding of nutritional information after brief and extended time exposure to food imagery.

Novel Food-Based Product Communication: A Neurophysiological Study

The steady increase in the global food demand requires alternative sources. Food sources from invertebrates could be a viable alternative. Despite a growing interest in terrestrial invertebrates as novel food, Western consumers have to cope with fears and taboos. This research aims to investigate possible communication strategies of novel food through labels. To understand the complexity underlying food choice and novel food attitude, two studies were carried out. In Study 1, the main drivers in the food decision-making process were identified. Based on these results, in Study 2, two different food labels for crackers made with earthworm flour were designed. Applying a neurophysiological approach, we measured participants' neuropsychophysiological activation and behavioural response while watching food labels. A video on nutritional and ecological issues was shown to consumers to reduce aversion towards earthworms as food. The results in Study 1 indicate health and sensory dimensions as the major drivers in food choice. The data of Study 2 supported the effectiveness of the statement about nutritional qualities of the products on male participants, who tend to have a more positive reaction than female participants toward the novel product made with earthworm flour when the label's claim focuses on nutritional advantages. Limitations and practical implications are discussed.