Food Stimuli Research Articles

Effects of food stimuli on event-related potentials of restrained eating subgroups during task switching

Executive functions are thought to affect problematic eating behaviors in restrained eaters. While neurophysiological features of inhibitory control among restrained eaters in particular have been extensively investigated, considerably less is known about its influence on cognitive flexibility. The present study investigated the behavioral and neural correlates of food-related cognitive flexibility with event-related potentials (ERPs) associated in a task-switching paradigm among successful restrained eaters (SREs, n = 30) and unsuccessful restrained eaters (UREs, n = 32). Behavioral results revealed smaller switch reaction times among SREs than among UREs in both food-stimuli and neutral-stimuli tasks. ERP analyses indicated that neutral-switch trials, especially in UREs, displayed larger N2 amplitudes. In addition, SREs displayed larger P3 amplitudes in frontal, frontal-central, and central than UREs. P3 amplitude increased significantly during food-stimuli tasks compared to that during neutral-stimuli tasks. These results indicate that SREs possess better efficiency in enhanced cognitive transformation during the processing of target monitoring and conflict resolution. This is the first study to provide evidence for differences between SREs and UREs during task switching using ERP measures and reliance on different food-related processing strategies among SREs compared to UREs.

Investigation of eye tracking, electrodermal activity and facial expressions as biometric signatures of food reward and intake in normal weight adults

Pervasive exposure to a vast and varied food repertoire has contributed to the obesity epidemic. Within this issue, there is a need for a better understanding of the psychophysiological responses to food cues that precede food choice and food intake to establish how these responses contribute to the link between food availability and increasing obesity levels. Biometric measures such as eye tracking, electrodermal activity and facial expressions may separately or collectively provide deeper insight into psychophysiological processes underlying food reward and food intake. We examined how biometric responses differed in foods varying in fat and taste and explored how these biometric signatures to food cues were related to food preference behaviours, food choice, and food intake. We developed and tested a biometric food preference task designed to concurrently assess biometric responses (eye tracking, electrodermal activity and facial expressions) and food reward to visual food stimuli from different food categories in 100 normal weight adults. Food intake and selection was examined using a simultaneous choice ad libitum buffet. The results from this cross-sectional study showed significant differences in visual attention towards foods varying in fat content and taste prior to making rapid food choice decisions. Furthermore, the study found positive associations between maintained attention during a forced choice paradigm and subsequent food reward and food intake measures. Attention, arousal and facial expression during passive viewing were not associated with food reward or intake measures, except for an association between negative valence and explicit liking such that less liked foods elicited stronger negative facial expressions. The findings indicate that implicit, biometric responses to food cues predict both food reward and actual food intake.

Preserved Inhibitory Control Deficits of Overweight Participants in a Gamified Stop-Signal Task: Experimental Study of Validity.

BackgroundGamification in mental health could increase training adherence, motivation, and transfer effects, but the external validity of gamified tasks is unclear. This study documents that gamified task variants can show preserved associations between markers of behavioral deficits and health-related variables. We draw on the inhibitory control deficit in overweight populations to investigate effects of gamification on performance measures in a web-based experimental task.ObjectiveThis study tested whether associations between inhibitory control and overweight were preserved in a gamified stop-signal task (SST).MethodsTwo versions of an adaptive SST were developed and tested in an online experiment. Participants (n=111) were randomized to 1 of the 2 task variants and completed a series of questionnaires along with either the gamified SST or a conventional SST. To maximize its possible effects on participants’ inhibitory control, the gamified SST included multiple game elements in addition to the task itself and the stimuli. Both variants drew on the identical core mechanics, but the gamified variant included an additional narrative, graphical theme, scoring system with visual and emotional feedback, and the presence of a companion character. In both tasks, food and neutral low-poly stimuli were classified based on their color tone (go trials), but responses were withheld in 25% of the trials (stop trials). Mean go reaction times and stop-signal reaction times (SSRT) were analyzed as measures of performance and inhibitory control.ResultsParticipants in the gamified SST had longer reaction times (803 [SD 179] ms vs 607 [SD 90] ms) and worse inhibitory control (SSRT 383 [SD 109] ms vs 297 [SD 45] ms). The association of BMI with inhibitory control was relatively small (r=.155, 95% CI .013-.290). Overweight participants had longer reaction times (752 [SD 217] ms vs 672 [SD 137] ms) and SSRTs (363 [SD 116] ms vs 326 [SD 77] ms). Gamification did not interact with the effect of overweight on mean performance or inhibitory control. There were no effects of gamification on mood and user experience, despite a negative effect on perceived efficiency.ConclusionsThe detrimental effects of heightened BMI on inhibitory control were preserved in a gamified version of the SST. Overall, the effects of overweight were smaller than in previously published web-based and laboratory studies. Gamification elements can impact behavioral performance, but gamified tasks can still assess inhibitory control deficits. Although our results are promising, according validations may differ for other types of behavior, gamification, and health variables.

The Design of a GLP-1/PYY Dual Acting Agonist.

The two gut hormones GLP-1 and PYY3-36 , which are both secreted from the L-cells upon food stimuli, have a stronger inhibitory effect on food intake when they are combined, compared to their individual effects as single agonists. Although they are not homologous and share no sequence similarity, we show that a GLP-1 analogue can be designed to exhibit potent activity on both the Y2 and GLP-1 receptors. Dual acting hybrid analogues were realized by designing truncated and potent Y2 receptor PYY analogues, followed by integrating the critical residues into GLP-1. In this study, we show that one of these dual acting agonists acutely reduces food intake significantly more than the respective mono-agonist counterparts.

The Design of a GLP‐1/PYY Dual Acting Agonist

AbstractThe two gut hormones GLP‐1 and PYY3–36, which are both secreted from the L‐cells upon food stimuli, have a stronger inhibitory effect on food intake when they are combined, compared to their individual effects as single agonists. Although they are not homologous and share no sequence similarity, we show that a GLP‐1 analogue can be designed to exhibit potent activity on both the Y2 and GLP‐1 receptors. Dual acting hybrid analogues were realized by designing truncated and potent Y2 receptor PYY analogues, followed by integrating the critical residues into GLP‐1. In this study, we show that one of these dual acting agonists acutely reduces food intake significantly more than the respective mono‐agonist counterparts.

Effects of Nicotine and Tobacco-Related Products on the Feeding Behavior of the German Cockroach (Blattodea: Blattellidae).

Animals use olfaction to detect developmentally significant volatile organic compounds (VOCs) in their local environment. As part of a wider study aiming to demonstrate that the olfactory responses of animals to VOCs can be modified through the creation of a drug-addicted status and association with a selected VOC, we investigated nicotine and tobacco smoke particulate (TSP) extract as possible addictive compounds for male German cockroaches, Blattella germanica (Linnaeus). In feeding experiments using an artificial food stimulus, food treated with TSP extract was preferred over untreated food. Surprisingly, nicotine, which was expected to be the most important addictive tobacco component, did not induce noticeable effects on cockroach behavior. Both TSP extract and nicotine were shown to be phagostimulants. Olfactometry assays that measured odor-mediated insect behavior demonstrated that male B. germanica did not choose TSP-extract-treated food even when attempts were made specifically to train them via this modality. These results support a hypothesis that B. germanica needs to consume TSP-containing food to show a clear preference for this stimulus and that gustatory mechanisms are involved due to compounds present in the TSP extract.

Effects of Transcranial Direct Current Stimulation (tDCS) on Go/NoGo Performance Using Food and Non-Food Stimuli in Patients with Prader-Willi Syndrome.

Prader–Willi syndrome (PWS) is a neurodevelopmental genetic disorder characterized by multiple system involvement with hypotonia, poor suck with feeding difficulties, growth and other hormone deficiencies, intellectual disability, and behavioral problems with childhood onset of hyperphagia resulting in obesity, if not externally controlled. Transcranial direct current stimulation (tDCS) has been increasingly shown to modulate cognitive and behavioral processes in children and adults, including food-intake behaviors in patients with PWS. This study further reports the positive effects of brief tDCS sessions on Go/NoGo task performance involving food and non-food stimuli images, alterations in N2 brain amplitude, and genetic subgroup differences (maternal disomy 15, UPD; 15q11-q13 deletion, DEL) before and after tDCS as assessed by event-related potentials (ERPs) in 10 adults with PWS. The results indicate a group effect on baseline NoGo N2 amplitude in PWS patients with DEL vs UPD (p =0.046) and a decrease in NoGo N2 amplitude following tDCS (p = 0.031). Our tDCS approach also demonstrated a trend towards decreased response time. Collectively, these results replicate and expand prior work highlighting neurophysiological differences in patients with PWS according to genetic subtype and demonstrate the feasibility in examining neuromodulatory effects of tDCS on information processing in this patient population to stimulate additional research and treatment.

Cross-cultural emotional response to food stimuli: Influence of consumption context

Emotional responses elicited by certain types of food can be influenced by past experiences, frequency of consumption, culture, and other personal preferences. The present research aimed i) to investigate the impact of culture (Brazilian and Spaniard) on consumers' emotional responses and acceptability of different food stimuli, and ii) to explore the influence of evoked contexts. Brazilian (n = 437) and Spanish (n = 397) participants were exposed to three visual food stimuli (image of chocolate, potato chips, and yogurt) in an online survey and reported their emotional responses. Sociodemographic data, liking, and frequency of consumption were also collected. The evoked context in our study were designed and proposed, for each product and culture, based on four dimensions (consumption time, location, social setting, and hungry state). The evoked emotional lexicon was different for each food stimulus and was clearly influenced by the cultural factor. However, there are more similarities between cultures when evaluating the same product category. The evoked contexts were appropriated and influenced the citing frequency of some emotion terms, including positive ones. The most cited emotion terms tended to positively impact product liking ratings, acting as drivers of liking. Consumption level was positively related to liking regardless of cultural interactions for both chocolate and potato chips stimuli. In conclusion, the cultural background demonstrated to be an important impact factor to be considered for understanding the effects of product, consumption occasions, and degree of liking, on emotional responses to foods. These findings offer new possibilities to be explored in marketing messages for interventions or stimuli that guide food choices.

Does hunger promote the detection of foods? The effect of value on inattentional blindness

Although human perception has evolved into a potent and efficient system, we still fall prey to astonishing failures of awareness as we miss an unexpected object in our direct view when our attention is engaged elsewhere (inattentional blindness). While specific types of value of the unexpected object have been identified to modulate the likelihood of this failure of awareness, it is not clear whether the effect of value on inattentional blindness can be generalized. We hypothesized that the combination of hunger and food-stimuli might increase a more general type of value so that food stimuli have a higher probability to be noticed by hungry participants than by satiated participants. In total, 240 participants were assigned towards a hungry (16 h of fasting) or satiated (no fasting) manipulation and performed afterward a static inattentional blindness task. However, we did not find any effect of value on inattentional blindness based on hunger and food stimuli. We speculate that different underlying mechanisms are involved for different types of value and that value manipulations need to be strong enough to ensure certain value strengths.

Effect of different amount of food and female resource on competitive strategy and agonistic behavior of swimming crab (Portunus trituberculatus)

Obtaining limited resources is an important motivator behind competition in animals. In pond cultures of swimming crabs (Portunus trituberculatus) common resources that cause conflict are food and mates. To explore the effects of different levels of food stimulus (clam extract; CG, control group: 0; LCH, little clam homogenate: 5 mL; ACH, abundant clam homogenate: 25 mL) and mate stimulus (female-conditioned water FCW; SW, seawater: 85 L seawater; LFW, low concentration FCW: 21 L FCW + 64 L seawater; HFW, high concentration FCW: 85 L FCW) on competitive strategies and agonistic behaviors of male crabs, we built an agonistic behavior recording system. We analyzed behavior, changes of oxygen consumption rate (OCR), and the concentrations of glycogen, glucose, and lactate in chelipeds and hemolymph after fighting. The main results revealed the following: (1) With increased perceived availability of food, the frequency of contact and key behaviors was significantly higher in the CG and LCH group than the ACH group. Fight duration in the LCH group was significantly longer than in the ACH group. The fight intensity and OCR of the LCH group were significantly higher than CG and ACH group. The concentration of lactate in hemolymph and glucose in chelipeds of the LCH group were significantly higher than the ACH group. The concentration of glycogen in cheliped muscle of the LCH and ACH group was significantly higher than the CG. (2) The increased concentration of FCW in the HFW group caused the duration of fights and the frequency of contact behaviors to be higher than in the SW group. In the HFW group the key behaviors occurred significantly more than in the SW and LFW groups. Fight intensity was also higher in the HFW group than the other two groups, and the LFW group had higher fight intensity than the SW group. The OCR of LFW and HFW groups were significantly higher than the SW group. The lactate concentrations in hemolymph and chelipeds in the LFW group were significantly higher than those in the SW and LFW groups. The glycogen concentrations in the chelipeds of the LFW and HFW groups were significantly higher than in the SW group. These results showed that the crabs adopt different competitive strategies, either to fight or yield, depending on type and availability of resources. These strategies are associated with costs such as physical risk and energy expenditure. In pond cultures of swimming crabs, increasing the density of food and isolating females from males during the breeding season may help to reduce appendage mutilation or death caused by fighting, thereby increasing aquaculture efficiency.

Effects of hunger on emotional arousal responses and attention/memory biases.

In this study, we examined how emotional arousal interacts with hunger states and the processing of food stimuli. In general, arousal enhances the processing of high-priority information at the expense of lower priority information (Mather & Sutherland, 2011). Because food has been a biologically relevant stimulus in primates throughout evolution, detecting it in the environment and remembering its location has high priority. In our study, inducing arousal enhanced attention to subsequent food stimuli. In addition, we manipulated whether participants were hungry or sated to examine how hunger states would influence emotional processing. Previous research reveals that being hungry is associated with increases in norepinephrine, a key neurotransmitter involved in the arousal response. We found that, when sated, participants showed greater pupil dilation to emotional than neutral stimuli. In contrast, when hungry, pupil dilation responses were as strong to neutral as to emotional stimuli. Thus, when hungry, participants were less effective at differentiating the intensity of arousal responses to emotional versus neutral stimuli because of high arousal responses to neutral stimuli. Memory for food stimuli was enhanced compared with memory for nonfood stimuli for all participants but especially for hungry participants. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Primates' Food Preferences Predict Their Food Choices Even Under Uncertain Conditions

Primates’ food preferences are typically assessed under conditions of certainty. To increase ecological validity, and to explore primates’ decision making from a comparative perspective, we tested three primate species (Pan troglodytes, Gorilla gorilla gorilla, Macaca fuscata) (N = 18) in two food-preference tests that created different conditions of uncertainty. In the first, we showed subjects pairs of photographs of six foods in a randomized manner within each session, so subjects could not predict the next pairing and had to respond in accordance with their preferences. We found individual differences in subjects’ preference and differences in six subjects’ preferences when comparing their selections in this test to selections made when trials were blocked by food pairing (tested previously: Huskisson et al., 2020). In in each trial of the second test we paired the food stimuli with a ‘chance’ symbol, representing a random reward of one of the six foods. Across species, each subject’s propensity to select chance over the known food varied by food type: when the known option was highly preferred, subjects were less likely to select the chance symbol. Additionally, 61.11% of the subjects’ rates of selecting foods in the first test showed a positive trend with the rates of selecting the same foods under conditions of uncertainty here; three of these subjects’ selection rates were significantly correlated between tests. Finally, if the food chimpanzees received for selecting the chance symbol was a preferred food, they were more likely to select chance again in the subsequent trial.

In Search of the Most Reproducible Neural Vulnerability Factors that Predict Future Weight Gain: Analyses of Data from Six Prospective Studies.

We tested if we could replicate the main effect relations of elevated striatum and lateral orbitofrontal cortex (OFC) response to high-calorie food stimuli to weight gain reported in past papers in six prospective datasets that used similar fMRI paradigms. Participants in Study 1 (N = 37; M age = 15.5), Study 2 (N = 160; M age = 15.3), Study 3 (N = 130; M age = 15.0), Study 4 (N = 175; M age = 14.3), Study 5 (N = 45; M age = 20.8), and Study 6 (N = 49; M age = 31.1) completed fMRI scans at baseline and had their BMI and body fat (Studies 4 and 6 only) measured at baseline and over follow-ups. Elevated striatal response to palatable food images predicted BMI gain in Studies 1 and 6 and body fat gain in Study 6. Lateral OFC activation did not predict weight gain in any of the six studies. Results provide limited support for the hypothesis that elevated reward region responsivity to palatable food images predicts weight gain. Factors that make replication difficult are discussed and potential solutions considered.

Cognitive and hormonal regulation of appetite for food presented in the olfactory and visual modalities

The ability to regulate appetite is essential to avoid food over-consumption. The desire for a particular food can be triggered by its odor before it is even seen. Using fMRI, we identify the neural systems modulated by cognitive regulation when experiencing appetizing food stimuli presented in both olfactory and visual modalities, while being hungry. Regulatory instruction modulated bids for food items and inhalation patterns. Distinct brain regions were observed for up and down appetite-regulation, respectively the dorsomedial prefrontal cortex (dmPFC) and dorsolateral PFC. Food valuation engaged the ventromedial PFC and bilateral striatum. Furthermore, we identified a neurobiological marker for successful appetite upregulation. Individuals with higher blood levels of ghrelin were better at exercising up-regulation, and engaged the dmPFC more. These findings characterize the neural circuitry regulating food consumption within the healthy population and highlight how cognitive regulation modulates olfactomotor measures of olfaction.

Fasting oxyntomodulin, glicentin, and gastric inhibitory polypeptide levels are associated with activation of reward- and attention-related brain centres in response to visual food cues in adults with obesity: A cross-sectional functional MRI study.

Postprandial increases in gastrointestinal hormones are associated with reduced energy intake, partially through direct effects on the brain. However, it remains unknown whether the fasting levels of gastrointestinal hormones are associated with altered brain activity in response to visual food stimuli. We therefore performed a whole-brain regression cross-sectional analysis to assess the association between fasting brain activations according to functional magnetic resonance imaging, performed during viewing of highly desirable versus less desirable food images, with fasting levels of five gastrointestinal hormones (glucagon-like peptide [GLP]-1, GLP-2, oxyntomodulin, glicentin and gastric inhibitory polypeptide [GIP]) in 36 subjects with obesity. We observed that fasting blood levels of GIP were inversely associated with the activation of attention-related areas (visual cortices of the occipital lobe, parietal lobe) and of oxyntomodulin and glicentin with reward-related areas (insula, putamen, caudate for both, and additionally orbitofrontal cortex for glicentin) and the hypothalamus when viewing highly desirable as compared to less desirable food images. Future studies are needed to confirm whether fasting levels of oxyntomodulin, glicentin and GIP are associated with the activation of brain areas involved in appetite regulation and with energy intake in people with obesity.

The neural substrates of subliminal attentional bias and reduced inhibition in individuals with a higher BMI: A VBM and resting state connectivity study

Previous studies have shown that individuals with overweight and obesity may experience attentional biases and reduced inhibition toward food stimuli. However, evidence is scarce as to whether the attentional bias is present even before stimuli are consciously recognized. Moreover, it is not known whether or not differences in the underlying brain morphometry and connectivity may co-occur with attentional bias and impulsivity towards food in individuals with different BMIs. To address these questions, we asked fifty-three participants (age M = 23.2, SD = 2.9, 13 males) to perform a breaking Continuous Flash Suppression (bCFS) task to measure the speed of subliminal processing, and a Go/No-Go task to measure inhibition, using food and nonfood stimuli. We collected whole-brain structural magnetic resonance images and functional resting-state activity. A higher BMI predicted slower subliminal processing of images independently of the type of stimulus (food or nonfood, p = 0.001, εp2 = 0.17). This higher threshold of awareness is linked to lower grey matter (GM) density of key areas involved in awareness, high-level sensory integration, and reward, such as the orbitofrontal cortex [t = 4.55, p = 0.003], the right temporal areas [t = 4.18, p = 0.002], the operculum and insula [t = 4.14, p = 0.005] only in individuals with a higher BMI. In addition, individuals with a higher BMI exhibit a specific reduced inhibition to food in the Go/No-Go task [p = 0.02, εp2 = 0.02], which is associated with lower GM density in reward brain regions [orbital gyrus, t = 4.97, p = 0.005, and parietal operculum, t = 5.14, p < 0.001] and lower resting-state connectivity of the orbital gyrus to visual areas [fusiform gyrus, t = -4.64, p < 0.001 and bilateral occipital cortex, t = -4.51, p < 0.001 and t = -4.34, p < 0.001]. Therefore, a higher BMI is predictive of non food-specific slower visual subliminal processing, which is linked to morphological alterations of key areas involved in awareness, high-level sensory integration, and reward. At a late, conscious stage of visual processing a higher BMI is associated with a specific bias towards food and with lower GM density in reward brain regions. Finally, independently of BMI, volumetric variations and connectivity patterns in different brain regions are associated with variability in bCFS and Go/No-Go performances.

Do Food Odors Differently Influence Cerebral Activity Depending on Weight Status? An Electroencephalography Study of Implicit Olfactory Priming Effects on the Processing of Food Pictures

Attentional automatic processes and cerebral activity may differ between individuals with different weight statuses in the presence of food stimuli (e.g. odors, pictures). In the present study, we used an implicit olfactory priming paradigm to test the influence of non-attentively perceived food odors on the cerebral activity underlying the processing of food pictures, in normal-weight, overweight, and obese adults. A pear odor and a pound cake odor were used as primes, respectively priming sweet low-energy-density foods and high-energy-density foods. Event-related potentials were recorded while the participants passively watched pictures of sweet low and high-energy-density foods, under the two priming conditions plus an odorless control condition. The amplitude and latency of several peaks were measured (P100, N100, P200, N400). As a major result, we found that weight status influences the cerebral activity underlying the processing of food cues outside of consciousness, as early as the first detectable P100 peak.

Expectancy to Eat Modulates Cognitive Control and Attention Toward Irrelevant Food and Non-food Images in Healthy Starving Individuals. A Behavioral Study.

It is thought that just as hunger itself, the expectancy to eat impacts attention and cognitive control toward food stimuli, but this theory has not been extensively explored at a behavioral level. In order to study the effect of expectancy to eat on attentional and cognitive control mechanisms, 63 healthy fasting participants were presented with an affective priming spatial compatibility Simon task that included both food and object (non-food) distracters. The participants (N = 63) were randomly assigned to two groups: an “immediate expectancy” group made up of participants who expected to eat immediately after the task (N = 31; females = 21; age = 26.8 ± 9.6) and a “delayed expectancy” cohort made up of individuals who expected to eat a few hours later (N = 32; females = 21; age = 25.0 ± 8.0). Slower reaction times (RTs) toward the food and non-food distracters and a more pronounced effect on the RTs in the incompatible condition [i.e., the Simon effect (SE)] were noted in both groups. The effect of the food and non-food distracters on the RTs was more pronounced in the immediate with respect to the delayed expectancy group. The magnitude of the SE for the food and the non-food distracters was also greater in the immediate with respect to the delayed expectancy group. These results seem to indicate that when the expectancy to eat is short, the RTs are delayed, and the SE is more pronounced when food and non-food distracters are presented. Instead, when the expectancy to eat is more distant, the distracters have less of an effect on the RTs and the correspondence effect is smaller. Our results suggest that the expectancy to eat can modulate both attention orienting and cognitive control mechanisms in healthy fasting individuals when distracting details are competing with information processing during goal directed behavior.

Neural Correlates of Attentional Bias to Food Stimuli in Obese Adolescents

Adolescent obesity is an increasingly prevalent problem in several societies. Researchers have begun to focus on neurocognitive processes that may help explain how unhealthy food habits form and are maintained. The present study compared attentional bias to food stimuli in a sample of obese (n = 22) and Normal-weight (n = 18) adolescents utilizing an Attention Blink (AB) paradigm while electroencephalography (EEG) was recorded. We found lower accuracy and Event-Related Potential (ERP) P3 amplitudes during the presentation of food stimuli in AB trials for obese adolescents. These findings suggest an impaired ability of their brains to flexibly relocate attentional resources in the face of food stimuli. The results were corroborated by lower P3s also being associated with higher body mass index (BMI) values and poorer self-reported self-efficacy in controlling food intake. The study is among the few examining neural correlates of attentional control in obese adolescents and suggests automatic attentional bias to food is an important aspect to consider in tackling the obesity crisis.

BDNF influences neural cue-reactivity to food stimuli and food craving in obesity

There is increasing evidence that brain-derived neurotrophic factor (BDNF) impacts on the development of obesity. We are the first to test the hypothesis that BDNF levels might be associated with neural reactivity to food cues in patients suffering from obesity and healthy controls. We assessed visual food cue-induced neural response in 19 obese patients and 20 matched controls using functional magnetic resonance imaging and analyzed the associations between BDNF levels, food cue-reactivity and food craving. Whole-brain analysis in both groups revealed that food cues elicited higher neural activation in clusters of mesolimbic brain areas including the insula (food > neutral). Patients suffering from obesity showed a significant positive correlation between plasma BDNF levels and visual food cue-reactivity in the bilateral insulae. In addition, patients suffering from obesity with positive food cue-induced insula activation also reported significantly higher food craving than those with low cue-reactivity—an effect that was absent in normal weight participants. The present findings implicate that BDNF levels in patients suffering from obesity might be involved in food craving and obesity in humans. This highlights the importance to consider BDNF pathways when investigating obesity and obesity treatment.