How Relevant is Food Craving to Obesity and Its Treatment?

Tackling Cravings in Medical Weight Management: An Update on Pathophysiology and an Integrated Approach to Treatment

Background/Objectives: Food cravings involve a strong drive to consume palatable foods irrespective of nutritional status. Importantly, cravings contribute substantially to the obesity epidemic. Managing hunger alone is insufficient for weight management as this relates only to homeostatic eating and does not address the complex aetiology of hedonic eating and its crucial role in food cravings. Medical weight management clinics and anti-obesity medication trials do not routinely identify and address food cravings. Methods: We conducted a narrative review of the literature consisting of 115 peer-reviewed articles (original articles and reviews). We included articles focused on food craving pathophysiology, assessment, and management strategies providing contrasts against the current medical model of weight management seen in obesity pharmacotherapy trials as well as the current standard of practise. Results: We outline the neurohormonal and psychological drivers of cravings, which lead to a spectrum of eating behaviours, from comfort food eating to binge eating disorders. We provide an overview of ways of identification and measurement options, including their strengths and weaknesses, and an overview of management strategies and their cravings control efficacy, spanning lifestyle modifications like nutrition and sleep, psychological therapies (i.e., cognitive behavioural therapy [CBT], acceptance-based therapies such as mindfulness) and, last but not least, medications that not only are approved for weight reduction but reduce cravings. Finally, based on these findings, we provide a proposed integrated and iterative model that is able to evolve and adapt to the individual over time in tackling cravings for long-term weight loss maintenance. Conclusions: The findings emphasise the importance of cravings management and provide a synthesis on how cravings can be identified in a medical weight management setting, which can be practically implemented in an integrated iterative model spanning anti-obesity medications that have craving control data to evidence-based lifestyle and psychological interventions.

Trait food craving predicts functional connectivity between dopaminergic midbrain and the fusiform food area during eating imagery

Neurofunctional coupling between the dopaminergic midbrain (i.e., ventral tegmental area, VTA) and higher-order visual regions may contribute to food craving, leading to the onset or maintenance of obesity. We recently showed that the VTA resting-state functional connectivity with the occipitotemporal cortex, at the level of the fusiform gyrus (FFG), was specifically associated with trait food craving and the implicit bias for food images, suggesting that VTA-FFG connectivity may reflect the association between the visual representations of food and its motivational properties. To further test this hypothesis, this time we studied task-based functional connectivity in twenty-eight healthy-weight participants while imagining eating their most liked high-calorie (HC) or least liked low-calorie food (LC) or drinking water (control condition). Trait food craving scores were used to predict changes in task-based functional connectivity of the VTA during imagery of HC compared to LC foods (relative to the control condition). Trait food craving was positively associated with the functional connectivity of the VTA with the left FFG: people with higher trait food craving scores show stronger VTA-FFG connectivity, specifically for the imagery of the liked HC foods. This association was not linked to the quality of imagery nor to state measures of craving, appetite, or thirst. These findings emphasize the contribution of the functional coupling between dopaminergic midbrain and higher-order visual regions to food craving, suggesting a neurofunctional mechanism by which the mental representations of the HC food we like can become much more salient if not irresistible.

Efficacy of Transcranial Direct Current Stimulation for Controlling of Food Craving in Subjects With Overweight or Obesity: A Pilot Study

OBJECTIVE

We aim to explore the effects of transcranial direct current stimulation (tDCS) on food craving improvement and changes in brain function associated with craving by conducting a total of 10 sessions of tDCS over a period of 2 weeks on overweight and obese subjects.

METHODS

A total of 15 patients who were overweight or obese (body mass index [BMI] ≥23 kg/m2) were included. Weight, BMI, neuropsychological variables, and food craving-related variables were assessed. We measured absolute and relative power in 19 channels and analyzed quantitative electroencephalography (qEEG) according to the following frequency ranges: delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-25 Hz), high beta (25-30 Hz), and gamma (30-80 Hz).

RESULTS

After the application of tDCS, there was no significant reduction observed in weight and BMI. However, all measures related to food and eating showed a decrease in the intensity of cravings, and there was also a significant reduction in depression, anxiety, and perceived stress. In qEEG analysis, an increase in theta waves was observed in the left frontal area (F7 and F3), an increase in alpha waves in the right parietal area (P4), and a decrease in beta waves in the frontal area (FP2) and occipital area (O1).

CONCLUSION

This study confirmed the beneficial effects of tDCS on food craving regulation in overweight or obese individuals and observed improved scores in psychological factors such as depression and anxiety. Furthermore, neurophysiological changes related to food craving were observed using qEEG.

Applying psycho-behavioural phenotyping in obesity characterization

Individual differences in obesity, beyond being explained by metabolic and medical complications, are understood by alterations in eating behaviour which underlie psychological processes. From this psychological perspective, studies have identified several potential characteristic features at the psycho-behavioural level that could additionally explain the maintenance of chronic excess weight or the unsuccessful results of current treatments. To date, despite the growing evidence, the heterogeneity of the psychological evidence associated with obesity has made it challenging to generate consensus on whether these psycho-behavioural phenotypes can be a complement to improve outcomes of existing interventions. For this reason, this narrative review is an overview focused on summarizing studies describing the psycho-behavioural phenotypes associated with obesity. Based on the literature, three psychological constructs have emerged: reward dependence, cognitive control, and mood and emotion. We discuss the clinical implications of stratifying and identifying these psycho-behavioural profiles as potential target for interventions which may ensure a better response to treatment in individuals with obesity. Our conclusions pointed out a considerable overlap between these psycho-behavioural phenotypes suggesting bidirectional interactions between them. These findings endorse the complexity of the psycho-behavioural features associated with obesity and reinforce the need to consider them in order to improve treatment outcomes.

Anodal stimulation of inhibitory control and craving in satiated restrained eaters

OBJECTIVES

Eating and weight disorders are severe and complex clinical conditions which, among other behaviors, include (attempts at) restrained eating, food avoidance, following dietary rules, and overeating. Comparable to women with obesity, restrained eaters (RE) without formal eating disorder diagnosis are worse at inhibiting their motor responses than unrestrained eaters (URE). According to neuroimaging studies, the right inferior frontal gyrus (rIFG) is involved in inhibitory control which, in turn, could be improved by neuromodulation such as anodal transcranial direct current stimulation (tDCS) across rIFG.

METHODS

This double-blind sham-controlled cross-over study was conducted after a standardized breakfast. Normal-weight female RE und URE performed a stop-signal task (SST) with food and non-food stimuli during sham or anodal tDCS. Food craving, hunger, and satiety were self-reported before and after tDCS. We employed a mixed between-subjects (group: RE vs. URE) and within-subjects factorial design (tDCS: anodal tDCS vs. sham; stimuli: food vs. control pictures).

RESULTS

Breakfast consumption was comparable for RE and URE, as well as craving, hunger, and thirst. Regarding inhibitory control, a significant two-way interaction between group and tDCS ermerged: RE had longer stop-signal reaction times (SSRTs) during sham tDCS, but they improved to the level of URE by application of anodal tDCS.

DISCUSSION

Results replicated an inhibitory control deficit in RE with longer SSRTs compared to URE without stimulation. During anodal tDCS to the rIFG, reduced SSRTs in RE indicated an improvement in inhibitory control. The findings suggest a specificity of rIFG stimulation in at-risk groups with regards to inhibitory control irrespective of craving.

The association between anxiety sensitivity and food cravings among individuals seeking treatment for weight-related behaviors

BACKGROUND

A better understanding of risk-factors associated with state-like food cravings may be one clinically relevant component in an effort to better understand obesity. Existing work has shown anxiety sensitivity (AS) to be a significant risk factor for increased cravings across a variety of health behaviors (e.g., smoking, alcohol use). Yet, no work has examined the relationship between AS and state-like food cravings. Therefore, the current study sought to examine the association between AS and a variety of state-like food cravings, including: (1) an intense desire to eat, (2) anticipation of relief from negative states and feelings/improvement in mood that may result from eating, (3) obsessive preoccupation with food or lack of control over eating, and (4) craving as a physiological state.

METHODS

Participants included 161 (Mage = 31.58, SD = 10.71; 60.9 % female) individuals seeking treatment for weight-related behaviors.

RESULTS

Results indicated that elevated AS was associated with reinforcement-based and physiological food cravings.

CONCLUSION

Our findings indicate that there may be clinical utility in screening for AS among individuals seeking treatment for weight-related behaviors in efforts to better understand specific types of food craving.

Adolescent eating behaviors in the UAE: Time to intervene

Background:

Obesity is the single most burdensome lifestyle disease, which has reached epidemic proportions. This study aimed to examine the eating behavior patterns and beliefs in a group of adolescents living in the United Arab Emirates (UAE).

Procedure:

A questionnaire was administered to adolescents (aged 11 and 18 years) attending outpatients' clinics at governmental health facilities. Informed consent was obtained, and the questionnaire was available in English or Arabic languages.

Results:

In all, 36 adolescent subjects participated in our study with 12 males and 24 females. UAE nationals constituted 72% of our participants and 28% were of other ethnic backgrounds; 75% were overweight to obese with 17% normal and 8% underweight. The majority of patients were healthy with only 6 patients suffering chronic medical diseases. We uncovered that in less than half of our cohort, the decision to eat came directly from the individuals themselves, but it was more influenced by their families. Food consumption was largely in response to physical hunger with the sensation perceived in the upper abdomen by one-third and the remainder localizing it to various other areas. Excessive caloric intake with frequent meals and snacks was also reported. Our study subjects decided what to consume mainly based on what appeared appetizing, followed by availability and cravings and to a lesser extent based on health recommendations. Excessive speed of food ingestion was self-reported in the majority of participants. Moreover, almost half of the adolescents were unable to turn down food offerings from their close family members and over one-fourth were unable to refuse food from other persons. Common symptoms reported included dysphoric mood, disordered sleep, decreased energy and concentration difficulties as well as low self-esteem.

Conclusion:

Our study uncovered certain eating behaviors in the cohort of adolescents, which may be important in promoting weight gain. These included misconceived hunger signals, excessive frequency, amount and speed of food consumption as well as more focus on food taste, inattentiveness to cravings and a strong social influence on food intake decisions. The findings of our study aim to shed some light on the eating patterns among adolescents and encourage research to investigate eating behaviors on an expanded scale evaluating ethnic, gender and age-related differences.

Food cravings and loss-of-control eating in youth: Associations with gonadal hormone concentrations

OBJECTIVE

Among youth with overweight, food cravings (FC) are associated with loss-of-control (LOC)-eating, but the impact of sex-associated biological characteristics on this relationship is unknown. We examined whether sex and gonadal hormone concentrations moderated the relationships between FC and LOC-eating severity among healthy boys and girls across the weight strata in natural and laboratory environments.

METHOD

Using ecological momentary assessment (EMA), FC, and LOC-eating severity were reported 3-5 times a day for 2 weeks. In the laboratory, participants reported FC, consumed lunch from a buffet test meal designed to simulate LOC-eating, and rated LOC-eating severity during the meal.

RESULTS

Eighty-seven youth (13.0 ± 2.7 years, 58.6% female, 32.2% with overweight/obesity) participated. EMA measured general and momentary FC were positively associated with LOC-eating severity (ps < .01), with no differences by sex (ps = .21-.93). Estradiol and progesterone significantly moderated the relationships between FC and LOC-eating such that general FC and LOC-eating severity were only positively associated among girls with greater (vs. lower) estradiol (p = .01), and momentary FC and LOC-eating severity were only positively associated among girls with greater (vs. lower) progesterone (p = .01). Boys' testosterone did not significantly moderate the associations between FC and LOC-eating severity (ps = .36-.97). At the test meal, pre-meal FC were positively related to LOC-eating severity (p < .01), without sex or hormonal moderation (ps = .20-.64).

DISCUSSION

FC were related to LOC-eating severity in boys and girls. In the natural environment, gonadal hormones moderated this relationship in girls, but not boys. The mechanisms through which gonadal hormones might affect the relationship between FC and LOC-eating warrant investigation.

Food reinforcement and habituation to food are processes related to initiation and cessation of eating

An individual bout of eating involves cues to start eating, as well as cues to terminate eating. One process that determines initiation of eating is food reinforcement. Foods with high reinforcing value are also likely to be consumed in greater quantities. Research suggests both cross-sectional and prospective relationships between food reinforcement and obesity, food reinforcement is positively related to energy intake, and energy intake mediates the relationship between food reinforcement and obesity. A process related to cessation of eating is habituation. Habituation is a general behavioral process that describes a reduction in physiological or affective response to a stimulus, or a reduction in the behavioral responding to obtain a stimulus. Repeated exposure to the same food during a meal can result in habituation to that food and a reduction in consumption. Habituation is also cross-sectionally and prospectively related to body weight, as people who habituate slower consume more in a meal and are more overweight. Research from our laboratory has shown that these two processes independently influence eating, as they can account for almost 60% of the variance in ad libitum intake. In addition, habituation phenotypes show reliable relationships with reinforcing value, such that people who habituate faster also find food less reinforcing. Developing a better understanding of cues to start and stop eating is fundamental to understanding how to modify eating behavior. An overview of research on food reinforcement, habituation and food intake for people with a range of weight status and without eating disorders is provided, and ideas about integrating these two processes that are related to initiation and termination of a bout of eating are discussed.

Getting to the heart of food craving with resting heart rate variability in adolescents

BACKGROUND

There is an epidemic of obesity in children and adolescents. Research into the self-regulatory factors that drive eating behavior is of critical importance. Food craving contributes to overeating and difficulty with weight loss and is strongly correlated with self-regulation. High-frequency heart rate variability (HF HRV) reflects parasympathetic activity and is positively associated with self-regulation. Few studies of HF HRV and food craving have been conducted in adolescents. The current study examined the association between HF HRV and food craving in a large-scale sample of healthy adolescents.

METHOD

Electrocardiogram (ECG) was recorded in 134 healthy adolescents aged 10-17 during a 7-min resting state. Participants also completed the Food Craving Questionnaire-Trait (FCQ-T). The relative power of HF HRV was calculated. Association between HF HRV and food craving was examined in the context of sex and age. Next, the relative significance of all food craving subscales was considered in relation to HF HRV.

RESULTS

HF HRV was inversely correlated with food craving, taking into account sex and age. Considering all the subscales of FCQ-T in relation to HF HRV, the "lack of control over eating" subscale accounted for the most significant variance.

CONCLUSION

This was the first study to evaluate resting HRV and eating behaviors in a large-scale adolescent sample. HF HRV was negatively associated with food craving, with lower HF HRV correlating with higher food craving, especially in the context of diminished control over eating. HF HRV could be a potential biomarker for food craving and food-related self-regulation capacity, and therefore may aid weight management interventions.

A Randomized Study of Food Pictures-Influenced Decision-Making Under Ambiguity in Individuals With Morbid Obesity

BACKGROUND AND AIMS

In addition to craving responses to salient food cues, the anticipation of short-term rewarding consumption of palatable food may overrun the anticipation of long-term negative consequences of obesity. The present investigation addressed the potential interplay of food cravings and decision-making abilities in individuals with obesity.

METHOD

Study 1 included 107 bariatric surgery candidates with class 2/3 obesity (OB-group) and study 2 included 54 individuals with normal weight/pre-obesity (nonOB-group). In both studies, standardized questionnaires concerning food cravings, food addiction, and psychopathology were administered. A cue-reactivity paradigm was used to measure craving responses toward semi-individualized images of highly palatable, processed food/fruit (appetitive food cues) compared to images of raw vegetables (non-appetitive food cues). Decision-making was measured with a modified computerized version of the Iowa Gambling Task (IGT) with food pictures. Both groups were divided into two subgroups that were randomized to different IGT conditions. In one IGT condition the advantageous IGT card decks were covered by pictures of palatable, processed food or fruit and the disadvantageous decks by images of raw vegetables (= congruent condition), and in the other IGT condition vice versa.

RESULTS

Participants in the OB-group admitted on average higher craving responses toward palatable, processed food or fruit cues compared to pictures of raw vegetables. This was not the case in the nonOB-group. Contrary to our hypothesis, decision-making performance in both groups was worse when pictures of palatable, processed food or fruit were associated with advantageous IGT card decks compared to performance when those pictures were linked to the disadvantageous decks. The interference effect of food pictures processing on advantageous decision-making has been observed particularly in those individuals of the OB-group who exhibited high craving responses toward palatable, processed food cues or high levels of food addiction.

DISCUSSION

The results indicate that food pictures processing interferes with decision-making, regardless of weight status. Opposed to the hypothesis, stronger tendencies to avoid than to approach pictures presenting processed, tasty food were observed. Further research should examine how cognitive avoidance tendencies toward processed, high energy food and approach tendencies toward healthy food can be transferred to real life situations.

Eating disorders: Do PET and SPECT have a role? A systematic review of the literature

A systematic review was implemented according to PRISMA guidelines on Pubmed, Psychinfo, Medline, Embase to fill the existing literature gap on the effectiveness of using Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) in Anorexia Nervosa (AN), Bulimia Nervosa (BN) and Binge Eating Disorder (BED). Twenty-two articles were included. Four studies reported an increased density in 5-hydroxytryptamine receptor (5-HT_1A) in fronto-temporo-parietal regions in both affected and recovered AN as well as in BN. The 5-HT transporter (5-HTT) binding was increased or diminished in different specific cortical areas and in relation to Eating Disorder (ED) subtypes. Some evidences of blunted Dopamine (DA) release in the putamen in BN patients suggest that their DA function might be impaired as in addictive behaviours. Studies estimating the regional Cerebral Blood Flow (rCBF) with SPECT demonstrated that temporal areas seem to play a key role in ED corroborating the hypothesis of a cingulate-temporal cortical dysfunction in AN. In addition, alterations of both parietal and prefrontal cortex provide a possible common neural substrate in AN. Studies included in this review are heterogeneous preventing robust conclusions, however, our findings add knowledge on some of the neurotransmitters involved in ED.

The Transdiagnostic Nature of Cravings: Smoking Cessation and Food Craving in Pregnancy

OBJECTIVES

Smoking cessation prior to pregnancy is strongly encouraged due to the adverse effects of tobacco use on the developing fetus, but appears to also increase risk of excess gestational weight gain (GWG). Smoking cessation has previously been shown to cause weight gain in non-pregnant individuals, in part due to an increase in food craving frequency. Food craving frequency in pregnancy is a known predictor of excess GWG, but has not yet been examined in relation to pre-pregnancy smoking status. This study sought to test the hypothesis that pre-pregnancy smoking cessation elevates excess GWG risk via an increase in food craving frequency.

METHODS

Pregnant women (n = 82) completed measures of pre-pregnancy tobacco use and current general and specific food cravings. Gestational weight gain was calculated based on participant self-report of pre-pregnancy weight and data on weight prior to delivery culled from medical records.

RESULTS

Pre-pregnancy tobacco use was associated with significantly greater food craving frequency in pregnancy (p = .05), specifically for high-fat and fast-foods (both p < .05), compared to women who did not smoke. Emotional and physiological aspects of cravings accounted for 35% of the variance in excess GWG (p < .03).

CONCLUSIONS

Pre-pregnancy smoking appears predictive of food raving frequency in pregnancy and could thus contribute to excess GWG risk. Findings highlight the importance of incorporating strategies for managing cravings into behavioral interventions promoting healthy GWG for women endorsing pre-pregnancy tobacco use.

Associations of Sleep with Food Cravings, Diet, and Obesity in Adolescence

Background: Sleep and dietary intake/quality can contribute to excess weight gain, but food cravings may influence these relationships. This cross-sectional study examined the relationship of adolescents’ sleep characteristics with dietary intake/quality and obesity and whether food cravings mediated these relationships. Methods: Sleep measures were calculated based on 24-h accelerometry, and height and weight were directly measured to calculate body mass index (BMI) z-scores. Food cravings were assessed by the Food Craving Inventory (FCI). Dietary intake and quality were calculated based on dietary recalls. Multivariable linear regression was used to examine the associations among sleep, food cravings, dietary intake/quality, and obesity, adjusting for confounders. Results: In total, 256 adolescents (ages 10–16 years) had complete data; 42% were non-White and 45% were boys. Sleep efficiency was inversely associated with sweet cravings and FCI-28. Sleep duration, meeting the sleep duration guidelines, and fruit/vegetable cravings were each positively associated with dietary quality. Sleep duration was negatively associated with BMI z-score. Mediation models were not performed as no sleep parameter was associated with both cravings and dietary intake/quality or BMI z-score. Conclusions: Associations existed among poor sleep, quantity and quality, with more frequent food cravings and worse dietary quality. Sleep may underlie adolescent obesogenic behaviors.

Association of food cravings with weight gain, overweight, and obesity in patients after liver transplantation

OBJECTIVE

After liver transplantation (LTx), patients often gain weight and many become overweight or obese; however, the association between LTx and food craving (FC) is unknown. The aim of this study was to describe FC among patients after LTx and verify its association with weight gain and obesity.

METHODS

This was a cross-sectional study that assessed 301 patients who underwent LTx (55.1 ± 12.7 y of age; time since LTx 6.6 ± 4.4 y; 64.1% men). Pregnant or nursing women were excluded. Patients were interviewed once either in the outpatient clinic or by completing the online questionnaire, from August 2016 to February 2017.

RESULTS

The median weight variation after Ltx was 8 kg (ranging from -16 to +41 kg). At evaluation, 62.5% (n = 188) of the patients presented excessive weight and 22.3% (n = 67) presented with obesity. The average score on the Food Craving Questionnaire-State (FCQ-S) was 33.4 ± 9 and for the Food Craving Questionnaire-Trait (FCQ-T) the median score was 68 (39-163). The FCQ-T dimensions of lack of control, preoccupation, emotion, environmental triggers/stimuli, and guilt correlated positively with weight gain (P < 0.05). The desire dimension on the FCQ-S was significantly associated with overweight in post-LTx patients (P < 0.05) and the FCQ-T dimensions [negative reinforcement (P = 0.013), lack of control (P = 0.016), emotion (P = 0.009), environmental triggers/stimuli (P = 0.029), and guilt (P = 0.007)] were associated with obesity.

CONCLUSION

Lack of control, preoccupation, emotion, trigger, and guilt were positively correlated with weight gain. Desire was significantly associated with overweight. Negative reinforcement, lack of control, emotion, environmental triggers/stimuli, and guilt were associated with obesity.

Effects of working memory on naturally occurring cravings

Elaborated Intrusion (EI) theory posits a key role for visuospatial working memory (WM) in craving. In line with the predictions of EI theory, several studies have found that WM and craving show mutually interfering effects - for example, performance of visuospatial WM tasks has been found to attenuate naturally occurring cravings. However, the extent to which these effects are driven specifically by visuospatial processing remains unclear. We conducted two experiments to investigate the effects of WM on naturally occurring cravings in more detail. In experiment 1, we examined whether such effects are driven specifically by visuospatial WM processes or can also be induced by a verbal WM task. Subjective craving ratings were attenuated equally by performance of visuospatial and verbal WM tasks, suggesting that craving is not dependent specifically on visuospatial processing. In experiment 2, we examined whether effects of visuospatial WM on craving could be driven by simple distraction. Naturally occurring cravings were attenuated in a control condition with minimal WM demands (watching a video). However, the magnitude of attenuation was significantly greater in a visuospatial WM condition. Taken together, these findings highlight a key role for WM in the attenuation of naturally occurring craving, but do not support the hypothesis that such effects are dependent specifically on visuospatial processing.

Compulsive eating behaviors in Parkinson's disease

PURPOSE

Eating disorders are common in Parkinson's disease (PD) patients and often class in Impulse control disorders, however, little is known about their phenomenology. Specific symptoms and comorbidities were described in a group of PD patients in this preliminary study.

METHODS

Over a period of 6 months, 51 PD patients who experienced significant changes in eating habits following diagnosis of PD and were interviewed during regularly scheduled follow-up visits. We assessed each patient's height and weight, impulsivity, psychological distress, current eating disorder symptoms, food addiction, food habits and craving.

RESULTS

Among the PD patients who experienced modified dietary habits following diagnosis, few exhibited binge eating disorders (BED) full criteria (3.9%). However, 21.6% of patients experienced episodes of out-of-control eating with a large quantity of food in short time and 39.2% satisfied food addiction (FA) criteria without binge eating disorder. Food cravings more than once a week were experienced in approximately half of the population including all FA patients. Regarding comorbidities, FA PD patients present impulsive features and anxiety.

CONCLUSIONS

This study confirms the existence of FA profile in PD patients. Eating disorders even in PD are complex and have a cross-cutting criteria related to out-of-control eating, FA, and BED. The association of anxiety with PD-related food addiction, contrary to L-dopa equivalent daily dose mean score or the presence of dopamine agonists, underline the complex sustainability of the dopaminergic brainstem support. A study on their detailed prevalence in this population could be helpful to better understand unspecified feeding or eating disorder.

CLINICAL TRIAL NUMBER

DR-2012-007.

NAME OF THE REGISTRY

French Committee for the Protection of Persons (CPP) & French National Commission on Computing and Liberty (CNIL).

LEVEL OF EVIDENCE

Level V, descriptive study.

Sweet cognition: The differential effects of glucose consumption on attentional food bias in individuals of lean and obese status

In general, glucose consumption improves cognitive performance; however, it is unknown whether glucose specifically alters attentional food bias, and how this process may vary by BMI status. We hypothesized that glucose consumption would increase attentional food bias among individuals of obese BMI status more so than among individuals of lean BMI status. Participants (N = 35) completed the n-back, a working memory task modified to assess attentional food bias (ATT-Food), under fasting and glucose challenge conditions. We computed pre-post changes in ATT-Food, blood glucose and insulin (∆BG & ∆BI), and perceived task-stress (∆stress). After the second cognitive test and blood draw, participants ate lunch and completed a "taste test" of highly palatable foods, and we recorded food consumption. Pre-post changes in ATT-Food were greater among participants of obese (relative to lean) BMI status (F(1,33) = 5.108, p = .031). Greater ∆ATT-Food was significantly associated with greater ∆BG (r = .462, p = .007) and reduced ∆stress (r =-.422, p = .011), and marginally associated with greater taste-test eating (r =.325, p = .057), but was not associated with ∆BI. Our findings suggest that individuals of obese BMI status may exhibit "sweet cognition," as indexed by greater attentional food bias following glucose ingestion, relative to individuals of lean BMI status. Among individuals of obese BMI status, sweet cognition may arise from difficulty broadening attention toward non-food cues after consuming a high glucose load, thereby potentially perpetuating sugar consumption. If confirmed by further research, measures of sweet cognition may help identify individuals with a phenotype of risk for obesity and greater sugar consumption, who may benefit from tailored interventions.

Polarity Specific Effects of Cross-Hemispheric tDCS Coupled With Approach-Avoidance Training on Chocolate Craving

Transcranial Direct Current Stimulation (tDCS) over the Dorsolateral Prefrontal Cortex (DLPFC) has already been shown to decrease craving for food. However, it remains unclear whether a single session of tDCS combined with a cognitive bias modification (CBM) task may affect explicit and implicit measures of craving for chocolate. Fifty-one healthy volunteers (38 females; mean age: 22.12 ± 3.38) were randomly allocated to CBM training based on the Approach Avoidance task and either Sham, Right anodal-Left cathodal (RALC), or Left anodal-Right cathodal (LARC) tDCS. Results show that there was an increase in the explicit craving for chocolate, as assessed by the Visual Analog Scale [F(2, 46) = 3.239, p = 0.048], from the baseline to post-intervention. Participants which received LARC tDCS were explicitly self-reporting more craving for chocolate than those that received RALC tDCS (p = 0.023). Moreover, this effect was also observed on the implicit measure [F(2, 46) = 4.168, p = 0.022]. LARC tDCS significantly increased the implicit preference for chocolate when comparing to both RALC (p = 0.009) and Sham tDCS (p = 0.034). Previous studies have shown that RALC tDCS over the PFC is able to effectively decrease craving for food. Interestingly, the present data not only does not reproduce such result, but instead it suggests that LARC tDCS can actually increase the preference for chocolate. This result is compatible with recent models of brain laterality, in which cue craving seems to be more dependent on the left hemisphere. Thus, shifting the activity to the left hemisphere (while simultaneously reducing the activity over the homotopic region) may have led to this increased implicit as well as explicit preference for chocolate.

Anxiety symptoms and emotional eating are independently associated with sweet craving in young adults

Sweet craving (SC), defined as a strong desire for sweet foods, seems to be closely related to negative emotions, such as anxiety and unhealthy eating behaviors. The objective was to investigate factors that are associated with SC and to assess the relationships among SC, anxiety symptoms, and eating behavior in university students. This was a cross-sectional study involving 300 students of both sexes (20.5 ± 4.4 years) who were freshmen in a Brazilian public university. Eating behavior was evaluated using the Three Factor Eating Questionnaire, anxiety symptoms were assessed using the Beck Anxiety Inventory, SC was identified by a yes/no question ("Have you had a very strong desire to eat sweet food over the last three months?"), and characterized by the Questionnaire for Assessment of Sweet Substance Dependence. Individuals with SC scored significantly higher for uncontrolled eating (UE), emotional eating (EE), and anxiety symptoms. Logistic regression analysis revealed that anxiety symptoms are independently associated with SC. In conclusion, negative emotions, like anxiety, and eating guided by these emotions can contribute to the SC phenomenon.

The computational form of craving is a selective multiplication of economic value

Craving is a specific desire state that biases choice toward the desired object. Although extremely common, and in its pathological form a major contributor to negative health outcomes as in addiction and obesity, craving is not well understood. In a laboratory model of craving, we find “craving” is reflected in people’s momentary willingness to pay for the things they desire, and for subjectively similar things, consistent with a transient, good-selective change in subjective valuation. We further find the value of the desired goods increases multiplicatively, which might explain several escalation behaviors associated with craving in real-world environments. This opens more lines of research regarding the computational form of craving in health and disease, with implications for marketing actions and consumer choice.

Craving is thought to be a specific desire state that biases choice toward the desired object, be it chocolate or drugs. A vast majority of people report having experienced craving of some kind. In its pathological form craving contributes to health outcomes in addiction and obesity. Yet despite its ubiquity and clinical relevance we still lack a basic neurocomputational understanding of craving. Here, using an instantaneous measure of subjective valuation and selective cue exposure, we identify a behavioral signature of a food craving-like state and advance a computational framework for understanding how this state might transform valuation to bias choice. We find desire induced by exposure to a specific high-calorie, high-fat/sugar snack good is expressed in subjects’ momentary willingness to pay for this good. This effect is selective but not exclusive to the exposed good; rather, we find it generalizes to nonexposed goods in proportion to their subjective attribute similarity to the exposed ones. A second manipulation of reward size (number of snack units available for purchase) further suggested that a multiplicative gain mechanism supports the transformation of valuation during laboratory craving. These findings help explain how real-world food craving can result in behaviors inconsistent with preferences expressed in the absence of craving and open a path for the computational modeling of craving-like phenomena using a simple and repeatable experimental tool for assessing subjective states in economic terms.

Testing a mobile mindful eating intervention targeting craving-related eating: feasibility and proof of concept

Theoretically driven smartphone-delivered behavioral interventions that target mechanisms underlying eating behavior are lacking. In this study, we administered a 28-day self-paced smartphone-delivered intervention rooted in an operant conditioning theoretical framework that targets craving-related eating using mindful eating practices. At pre-intervention and 1-month post-intervention, we assessed food cravings among adult overweight or obese women (N = 104; M age = 46.2 ± 14.1 years; M BMI = 31.5 ± 4.5) using ecological momentary assessment via text message (SMS), self-reported eating behavior (e.g., trait food craving), and in-person weight. Seventy-eight participants (75.0%) completed the intervention within 7 months ('all completers'), and of these, 64 completed the intervention within 3 months ('timely completers'). Participants experienced significant reductions in craving-related eating (40.21% reduction; p < .001) and self-reported overeating behavior (trait food craving, p < .001; other measures ps < .01). Reductions in trait food craving were significantly correlated with weight loss for timely completers (r = .30, p = .020), this pattern of results was also evident in all completers (r = .22, p = .065). Taken together, results suggest that smartphone-delivered mindful eating training targeting craving-related eating may (1) target behavior that impacts a relative metabolic pathway, and (2) represent a low-burden and highly disseminable method to reduce problematic overeating among overweight individuals. ClinicalTrials.gov registration: NCT02694731.

Hyperpalatability and the Generation of Obesity: Roles of Environment, Stress Exposure and Individual Difference

PURPOSE OF REVIEW

This review investigates how exposure to palatable food and its associated cues alters appetite regulation and feeding behaviour to drive overeating and weight gain.

RECENT FINDINGS

Both supraphysiological and physiological feeding systems are affected by exposure to palatable foods and its associated cues. Preclinical research, largely using rodents, has demonstrated that palatable food modulates feeding-related neural systems and food-seeking behaviour by recruiting the mesolimbic reward pathway. This is supported by studies in adolescents which have shown that mesolimbic activity in response to palatable food cues and consumption predicts future weight gain. Additionally, stress exposure, environmental factors and individual susceptibility have been shown to modulate the effects of highly palatable foods on behaviour. Further preclinical research using free-choice diets modelling the modern obesogenic environment is needed to identify how palatable foods drive overeating. Moreover, future clinical research would benefit from more appropriate quantification of palatability, making use of rating systems and surveys.

A Pilot Study on the Effects of Slow Paced Breathing on Current Food Craving

Heart rate variability biofeedback (HRV-BF) involves slow paced breathing (approximately six breaths per minute), thereby maximizing low-frequent heart rate oscillations and baroreflex gain. Mounting evidence suggests that HRV-BF promotes symptom reductions in a variety of physical and mental disorders. It may also positively affect eating behavior by reducing food cravings. The aim of the current study was to investigate if slow paced breathing can be useful for attenuating momentary food craving. Female students performed paced breathing either at six breaths per minute (n = 32) or at nine breaths per minute (n = 33) while watching their favorite food on the computer screen. Current food craving decreased during a first resting period, increased during paced breathing, and decreased during a second resting period in both conditions. Although current hunger increased in both conditions during paced breathing as well, it remained elevated after the second resting period in the nine breaths condition only. Thus, breathing rate did not influence specific food craving, but slow paced breathing appeared to have a delayed influence on state hunger. Future avenues are suggested for the study of HRV-BF in the context of eating behavior.

Guided imagery targeting exercise, food cravings, and stress: a multi-modal randomized feasibility trial

The purpose of this randomized wait-list controlled trial was to test the feasibility and preliminary efficacy of a guided imagery based multi-behavior intervention intended to address psychological stress, food cravings, and physical activity. Personalized guided imagery scripts were created and participants were instructed to practice guided imagery every day for 35 consecutive days. Of 48 women who enrolled, we report comparisons between 16 randomized to treatment with 19 who were wait-listed (overall Mage = 45.50; Mbodymassindex = 31.43). Study completers reported 89% compliance with practicing guided imagery during the intervention. A significant time-by-group interaction was observed with reductions in food cravings and increases in physical activity compared with wait-list controls. Telephone-based multi-behavior interventions that utilize guided imagery to address food cravings and exercise behavior appear to be acceptable for overweight and obese women. Future phone-based guided imagery research testing this skill to address multiple health behaviors is justified.

High definition transcranial pink noise stimulation of anterior cingulate cortex on food craving: An explorative study

Dysfunctional neural activity in the cortical reward system network has been implicated in food addiction. This is the first study exploring the potential therapeutic effects of high definition transcranial pink noise stimulation (HD-tPNS) targeted at the anterior cingulate cortex (ACC) on craving and brain activity in women with obesity who showed features of food addiction (Yale Food Addiction Scale score of ≥3). Sixteen eligible females participated in a randomized, double-blind, parallel group study. Participants received six 20-minute sessions of either 1 mA (n = 8) or sham (n = 8) stimulation with HD-tPNS over two weeks. Anode was placed above the ACC (Fz) with 4 cathodes (F7, T3, F8, and T4). Food craving was assessed using the Food Cravings Questionnaire State (FCQ-S) and brain activity was measured using electroencephalogram (EEG). Assessments were at baseline, and two days, four weeks, and six weeks after stimulation. A 22% decrease (mean decrease of -1.11, 95% CI -2.09, -0.14) was observed on the 5-point 'intense desire to eat' subscale two days after stimulation in the HD-tPNS group compared to sham. Furthermore, whole brain analysis showed a significant decrease in beta 1 activity in the ACC in the stimulation group compared to sham (threshold 0.38, p = 0.04). These preliminary findings suggest HD-tPNS of the ACC transiently inhibits the desire to eat and, thus, warrants further examination as a potential tool in combating food craving.

Reliability and Validity of the Korean Version of the General-Food Craving Questionnaire-Trait for Children

OBJECTIVE

The General-Food Craving Questionnaire-Trait (G-FCQ-T) is a validated, assessment scale for food craving. The aim of this study was to measure its reliability and validity for Korean children.

METHODS

A total of 172 children (94 boys and 78 girls) were selected to fill out a set of questionnaires, including the G-FCQ-T, the Children's version of the Dutch Eating Behavior Questionnaire (DEBQ-C), and the Three-Factor Eating Questionnaire (TFEQ) in the Korean language.

RESULTS

The internal consistency (Cronbach's alpha=0.933) and test-retest reliability (r=0.653) were satisfactory. The G-FCQ-T showed a significantly positive correlation with the DEBQ-C (r=0.560) and the TFEQ (r=0.397). The optimum cutoff score of the G-FCQ-T set by Receiver Operating Characteristics analysis was 51, with sensitivity and specificity of 0.833 and 0.825, respectively, for children.

CONCLUSION

The G-FCQ-T showed good reliability and validity for assessing food craving for children and could become a practial instrument in clinical and research settings.

When food becomes an obsession: Overweight is related to food-related obsessive-compulsive behavior

In this study, it was examined whether overweight is associated with food-related obsessions and compulsions. Participants with a healthy weight (n = 27) and participants who were overweight (n = 33) filled out the Yale-Brown-Cornell Eating Disorder Scale, the Eating Obsessive-Compulsive Scale, and the Emotional and Behavioral Reactions to Intrusions Questionnaire to assess frequency, distress, control, and reactance associated with food-related preoccupations and compulsions. Overweight participants showed increased food-related preoccupations, compulsive eating, and heightened emotional and behavioral reactance compared to participants with a healthy weight. Increased food-related obsessive-compulsiveness was also associated with unhealthy eating patterns.

Food Addiction, Binge Eating Disorder, and Obesity: Is There a Relationship?

Existing research suggests that there is an overlap between binge eating disorder (BED) and the construct of 'food addiction' (FA). The objective of this study was to determine the overlapping features of BED and FA through a comparison of the individual scales of commonly used tools including the Binge Eating Scale (BES) and the Yale Food Addiction Scale (YFAS) in a sample of Australian adults. Adults (>18 years of age) were invited to complete an anonymous online survey on FA. Binge eating was assessed through the BES and addictive eating behaviours were assessed through the YFAS (n = 1344). The prevalence and severity of both FA and binge eating increased across weight categories. The overall correlation between the total score from the BES and FA symptoms was r = 0.76, p < 0.001; for females it was r = 0.77, p < 0.001, and for males it was r = 0.65, p < 0.001. Total BES score and the BES emotion factor were most often associated with FA symptoms, as was demonstrated to produce stronger correlations with FA symptoms. In contrast, the BES behaviour factor was less strongly associated to FA with the majority of correlations <0.6. This study demonstrates the overlap between BED and FA, and highlights the possible unique differences between the forms of disordered eating.

Does culture create craving? Evidence from the case of menstrual chocolate craving

Craving is considered a key characteristic of diverse pathologies, but evidence suggests it may be a culture-bound construct. Almost 50% of American women crave chocolate specifically around the onset of menstruation. Research does not support popular accounts implicating physiological factors in menstrual chocolate craving etiology. We tested the novel hypothesis that greater menstrual craving prevalence in the U.S. is the product of internalized cultural norms. Women of diverse backgrounds (n = 275) reported on craving frequency and triggers and completed validated measures of acculturation. Foreign-born women were significantly less likely to endorse menstrual chocolate craving (17.3%), compared to women born to U.S.-born parents (32.7%, p = .03) and second generation immigrants (40.9%, p = .001). Second generation immigrant and foreign-born women endorsing menstrual chocolate craving reported significantly greater U.S. acculturation and lower identification with their native culture than non-menstrual cravers (all p < .001). Findings inform our understanding of food cravings, with important implications for the study of cravings in other domains.

A high-fat diet combined with food deprivation increases food seeking and the expression of candidate biomarkers of addiction

A mouse model has been developed to study the effect of dietary fat combined with food deprivation periods on palatable food seeking and on the expression of three potential addiction biomarkers in the nucleus accumbens: fumarate hydratase (FH), ATP synthase subunit alpha (ATP5a1) and transketolase (TKT). Forty C57BL/6 J male mice, four-week old, were fed either with a high-fat (HF) diet or standard diet along the experiment. After 3 weeks of differential feeding, animals underwent a two-week training period of two daily sessions where visual cues were paired either to palatable food (chocolate cereals) or no food at all. This training was prolonged one more week with similar, one daily sessions preceded by 12 hours of food deprivation. A behavioural test was finally conducted where mice were confined for 30 minutes either in food unpaired compartments or in compartments previously paired with cereals, but now with empty food trays. Total activity during this behavioural test and serum corticosterone levels right after it were similar in all experimental groups. Mice tested in food-paired compartments showed a marked preference for the empty food tray that gradually disappeared in standard diet-fed individuals but persisted in HF-fed mice. HF-fed mice also overexpressed FH, ATP5a1 and TKT, which positively correlated with the persistence of preference for the empty food tray. It is suggested that HF diets combined with food deprivation may enhance food seeking behaviours while upregulating FH/ATP5a1/TKT, which are further envisaged as biomarkers of addiction.

Psychometric Properties of the German Translated Version and Adaptation of the Food Craving Inventory

Dysfunctional eating behavior is a major risk factor for developing all sorts of eating disorders. Food craving is a concept that may help to understand better why and how these and other eating disorders become chronic conditions through non homeastatically-driven mechanisms. As obesity affects people worldwide, cultural differences must be acknowledged to apply proper therapeutic strategies. In this work, we adapted the Food Craving Inventory (FCI) to the German population. We performed a factor analysis of an adaptation of the original FCI in a sample of 326 men and women. We could replicate the factor structure of the FCI on a German population. The factor extraction procedure produced a factor solution that reproduces the four factors described in the original inventory, the FCI. Our instrument presents high internal consistency, as well as a significant correlation with measures of convergent and discriminant validity. The FCI-Deutsch (FCI-DE) is a valid instrument to assess craving for particular foods in Germany, and it could, therefore, prove useful in the clinical and research practice in the field of obesity and eating behaviors.

Trait-based food-cravings are encoded by regional homogeneity in the parahippocampal gyrus

Food cravings can reflect an intense trait-like emotional-motivational desire to eat palatable food, often resulting in the failure of weight loss efforts. Studies have linked trait-based food-cravings to increased risk of overeating. However, little is known about resting-state neural mechanisms that underlie food cravings. We investigated this issue using resting-state functional magnetic resonance imaging (fMRI) to test the extent to which spontaneous neural activity occurs in regions implicated in emotional memory and reward motivation associated with food cravings. Spontaneous regional activity patterns correlating to food cravings were assessed among 65 young healthy women using regional homogeneity analysis to assess temporal synchronization of spontaneous activity. Analyses indicated that women with higher scores on the Food Cravings Questionnaire displayed increased local functional homogeneity in brain regions involved in emotional memory and visual attention processing (i.e., parahippocampal gyrus and fusiform gyrus) but not reward. In view of parahippocampal gyrus involvement in hedonic learning and incentive memory encoding, this study suggests that trait-based food cravings are encoded by emotional memory circuits.

Ultra-brief non-expert-delivered defusion and acceptance exercises for food cravings: A partial replication study

Food cravings are a common barrier to losing weight. This article presents a randomised comparison of non-expert group-delivered ultra-brief defusion and acceptance interventions against a distraction control. A total of 63 participants were asked to carry a bag of chocolates for a week while trying to resist the temptation to eat them. A behavioural rebound measure was administered. Each intervention out-performed control in respect of consumption, but not cravings. These techniques may have a place in the clinical management of food cravings. We provide tentative evidence that the mechanism of action is through decreased reactivity to cravings, not through reduced frequency of cravings.

Incorporating food addiction into disordered eating: the disordered eating food addiction nutrition guide (DEFANG)

Although not formally recognized by the DSM-5, food addiction (FA) has been well described in the scientific literature. FA has emerged as a clinical entity that is recognized within the spectrum of disordered eating, particularly in patients with bulimia nervosa, binge-eating disorder and/or co-occurring addictive disorders and obesity. Integrating the concept of FA into the scope of disordered eating has been challenging for ED treatment professionals, since there is no well-accepted treatment model. The confusion surrounding the implications of FA, as well as the impact of the contemporary Westernized diet, may contribute to poor treatment outcomes. The purpose of this review is twofold. The first is to briefly explore the relationships between EDs and addictions, and the second is to propose a new model of conceptualizing and treating EDs that incorporates recent data on FA. Since treatment for EDs should vary based on individual assessment and diagnosis, the Disordered Eating Food Addiction Nutrition Guide (DEFANG) is presented as a tool for framing treatment goals and helping patients achieve sustainable recovery.

Reward-Induced Eating: Therapeutic Approaches to Addressing Food Cravings

The homeostatic controls over eating are inextricably linked to the reward aspects of eating. The result is an integrated response that coordinates the internal milieu with the prevailing environment. Thus, appetite, which reflects a complex interaction among the external environment, behavioral profile, and subjective states as well as the storage and metabolism of energy, has an important role in the regulation of energy balance. In the prevailing food environment which offers an abundance of food choices it is likely that the motivation to consume from a wide range of delectable foods plays a greater role in contributing to overeating than in the past when the motivation to eat was largely governed by metabolic need. The response to food-related cues can promote strong desires to eat known as cravings by activating the mesocorticolimbic dopamine neurocircuitry. Cravings are associated with subsequent eating and weight-related outcomes. Being able to control food cravings is a determinant of success at adhering to an energy-restricted diet regimen. Increased understanding of the neurocircuitry of appetite regulation, especially reward-related eating behavior, has provided potential targets for therapeutic anti-obesity agents specifically directed at reward mechanisms. The naltrexone-bupropion combination and lorcaserin, which are both approved by the US Food and Drug Administration (FDA) for long-term weight management, have shown promise in addressing craving-related eating behavior. Phentermine and liraglutide are approved as monotherapies for weight management. Preliminary research suggests that liraglutide, as well as phentermine alone or in combination with lorcaserin, may be effective in targeting food cravings. Food components such as thylakoid membranes have also been shown to influence food cravings. This review explores the concepts related to appetite and reward-induced eating behavior, as well as the pharmacological options and food-derived components that may be used to address food cravings.

Estradiol, SHBG and leptin interplay with food craving and intake across the menstrual cycle

OBJECTIVE

To understand the association between ovarian hormones, non-acute satiety hormones and craving calorie dense foods in the luteal phase.

METHODS

17 premenopausal women, mean age 23.2 y, mean BMI 22.4kg/m(2) with regular menstrual cycles were studied during late follicular (FP) and luteal phases (LP). Estradiol, progesterone, DHEAS, SHBG, insulin and leptin, were measured in fasting samples. The validated Food Craving Inventory was used to record the types of foods volunteers habitually ate - rich in fat, carbohydrate or sweet taste, as well as craved during the LP of their menstrual cycle.

RESULTS

Estradiol was inversely associated with leptin in FP (r=-0.62, p=0.01). Leptin was inversely associated with habitual intake of sweet foods, in both phases (FP: r=-0.64, p=0.01; LP: r=-0.63, p=0.01). SHBG in LP was positively associated with craving sweet and carbohydrate rich foods. Hierarchical cluster analysis revealed two groups of women, one with high estradiol, high estradiol/leptin ratio, high sweet and carbohydrate cravings (p<0.05); the other group had lower estradiol, lower estradiol/leptin ratio, and reported less craving.

CONCLUSIONS

The estradiol-leptin axis may be a determinant of luteal phase craving and habitual food intake in menstruating women.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01407692.

Long-Term Effects of Repeated Prefrontal Cortex Transcranial Direct Current Stimulation (tDCS) on Food Craving in Normal and Overweight Young Adults

BACKGROUND

The dorsolateral prefrontal cortex (DLPFC) plays an important role in the regulation of food intake. Several previous studies demonstrated that a single session of transcranial direct current stimulation (tDCS) of the DLPFC reduces food craving and caloric intake.

OBJECTIVES

We hypothesized that repeated tDCS of the right DLPFC cortex may exert long-term changes in food craving in young, healthy adults and that these changes may differ between normal and overweight subjects.

METHODS

Thirty healthy individuals who reported frequent food cravings without a prior history of eating disorders were initially recruited. Subjects were randomized into an ACTIVE group who received 5 days of real tDCS (20 minutes, anode right-cathode left montage, 2 mA with current density kept at 0.06 mA/cm2, 1 min ramp-up/ramp-down), and a SHAM group, who received one day of real tDCS, on the first day (same parameters), followed by 4 days of sham tDCS. Food craving intensity was examined by Food Craving Questionnaires State and Trait and Food Craving Inventory before, during, (5-days) and one month (30-days) after tDCS.

RESULTS

Single session of tDCS significantly reduced the intensity of current food craving (FCQ-S). Five days of active tDCS significantly reduced habitual experiences of food craving (FCQ-T), when compared to baseline pre-stimulation levels. Furthermore, both current (FCQ-S) and habitual craving (FCQ-T) were significantly reduced 30 days after active tDCS, while sham tDCS, i.e. a single tDCS session did not have significant effects. Also, active tDCS significantly decreased craving for fast food and sweets, and to a lesser degree for fat, while it did not have significant effects on craving for carbohydrates (FCI). There were no significant differences between individual FCQ-T subscales (craving dimensions) after 5 or 30 days of either sham or active tDCS. Changes in craving were not significantly associated with the initial weight, or with weight changes 30 days after the stimulation in the subjects.

CONCLUSIONS

The results confirm earlier findings that single session of tDCS has immediate effects in reducing food craving. They also show that repeated tDCS over the right DLPFC may increase the duration of its effects, which may be present 30 days after the stimulation. These results support further investigation of the use of tDCS in obesity.

Oxytocin enhances cognitive control of food craving in women

In developed countries, obesity has become an epidemic resulting in enormous health care costs for society and serious medical complications for individuals. The homeostatic regulation of food intake is critically dependent on top-down control of reward-driven food craving. There is accumulating evidence from animal studies that the neuropeptide oxytocin (OXT) is involved in regulating hunger states and eating behavior, but whether OXT also contributes to cognitive control of food craving in humans is still unclear. We conducted a counter-balanced, double-blind, within-subject, pharmacological magnetic resonance imaging experiment involving 31 healthy women who received 24 IU of intranasal OXT or placebo and were scanned twice while they were exposed to pictures of palatable food. The participants were instructed either to imagine the immediate consumption or to cognitively control the urge to eat the food. Our results show a trend that OXT specifically reduced food craving in the cognitive control condition. On the neural level, these findings were paralleled by an increase of activity in the middle and superior frontal gyrus, precuneus, and cingulate cortex under OXT. Interestingly, the behavioral OXT effect correlated with the OXT-induced changes in the prefrontal cortex and precuneus. Collectively, the present study provides first evidence that OXT plays a key role in the cognitive regulation of food craving in women by strengthening activity in a broad neurocircuitry implicated in top-down control and self-referential processing. Hum Brain Mapp 37:4276-4285, 2016. © 2016 Wiley Periodicals, Inc.

Gender-related Differences in Food Craving and Obesity

Food craving is often defined as a strong desire to eat. Much work has shown that it consistently and prospectively predicts eating and weight-related outcomes, contributing to the growing obesity epidemic. Although there are clear gender differences in the prevalence and health consequences of obesity, relatively little recent work has investigated gender differences in craving, or any sex-hormone-based differences as they relate to phases of the menstrual cycle. Here, we propose that gender-related differences in food craving contribute to gender-related differences in obesity. Drawing on findings in the addiction literature, we highlight ways to incorporate gender-based differences in food craving into treatment approaches, potentially improving the efficacy of obesity and weight loss treatment. Overall, this review aims to emphasize the importance of investigating gender differences in food craving, with a view towards informing the development of more effective treatments for obesity and weight loss.

The DSM-5 effect: psychological characteristics of new patients affected by Binge Eating Disorder following the criteria of the DSM-5 in a sample of severe obese patients

PURPOSE

The current study evaluated whether or not there were significant differences in psychopathological traits between three groups of individuals. The first was a group of patients seeking bariatric surgery diagnosed as being affected by Binge Eating Disorder (BED), according to the new criteria of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. This group (NEW BED group) did not meet BED diagnosis following the previous criteria listed in the DSM-IV-TR. The second group of individuals was composed of severely obese patients seeking bariatric surgery not affected by an eating disorder, according to the diagnostic criteria of the DSM-5 (OB group). The third group was composed of individuals within a healthy weight range (Control group).

METHODS

94 severely obese patients (33 in the NEW BED group and 61 in the OB group) were compared to the Control group including 41 participants on depression, anxiety and eating habits.

RESULTS

The NEW BED scored significantly higher than the OB group on the Beck Depression Inventory, both the subscales of the State Trait Anxiety Inventory, on disinhibition and hunger subscales of the Three-Factor Eating Questionnaire and on many subscales of the Eating Disorders Inventory.

CONCLUSIONS

The new, less restrictive diagnostic criteria for BED of the DSM-5 are useful in identifying obese patients affected by severe psychopathology and dysfunctional eating habits.

Shared and unique mechanisms underlying binge eating disorder and addictive disorders

Scientific interest in "food addiction" is growing, but the topic remains controversial. One critique of "food addiction" is its high degree of phenotypic overlap with binge eating disorder (BED). In order to examine associations between problematic eating behaviors, such as binge eating and "food addiction," we propose the need to move past examining similarities and differences in symptomology. Instead, focusing on relevant mechanisms may more effectively determine whether "food addiction" contributes to disordered eating behavior for some individuals. This paper reviews the evidence for mechanisms that are shared (i.e., reward dysfunction, impulsivity) and unique for addiction (i.e., withdrawal, tolerance) and eating disorder (i.e., dietary restraint, shape/weight concern) frameworks. This review will provide a guiding framework to outline future areas of research needed to evaluate the validity of the "food addiction" model and to understand its potential contribution to disordered eating.

Brain regulation of food craving: relationships with weight status and eating behavior

OBJECTIVES

Food craving is a driving force for overeating and obesity. However, the relationship between brain mechanisms involved in its regulation and weight status is still an open issue. Gaps in the studied body mass index (BMI) distributions and focusing on linear analyses might have contributed to this lack of knowledge. Here, we investigated brain mechanisms of craving regulation using functional magnetic resonance imaging in a balanced sample including normal-weight, overweight and obese participants. We investigated associations between characteristics of obesity, eating behavior and regulatory brain function focusing on nonlinear relationships.

SUBJECTS/METHODS

Forty-three hungry female volunteers (BMI: 19.4-38.8 kg m(-2), mean: 27.5±5.3 s.d.) were presented with visual food stimuli individually pre-rated according to tastiness and healthiness. The participants were instructed to either admit to the upcoming craving or regulate it. We analyzed the relationships between regulatory brain activity as well as functional connectivity and BMI or eating behavior (Three-Factor Eating Questionnaire, scales: Cognitive Restraint, Disinhibition).

RESULTS

During regulation, BMI correlated with brain activity in the left putamen, amygdala and insula in an inverted U-shaped manner. Functional connectivity between the putamen and the dorsolateral prefrontal cortex (dlPFC) correlated positively with BMI, whereas that of amygdala with pallidum and lingual gyrus was nonlinearly (U-shaped) associated with BMI. Disinhibition correlated negatively with the strength of functional connectivity between amygdala and dorsomedial prefrontal (dmPFC) cortex as well as caudate.

CONCLUSIONS

This study is the first to reveal quadratic relationships of food-related brain processes and BMI. Reported nonlinear associations indicate inverse relationships between regulation-related motivational processing in the range of normal weight/overweight compared with the obese range. Connectivity analyses suggest that the need for top-down (dlPFC) adjustment of striatal value representations increases with BMI, whereas the interplay of self-monitoring (dmPFC) or eating-related strategic action planning (caudate) and salience processing (amygdala) might be hampered with high Disinhibition.

The neurobiological basis of binge-eating disorder

Relatively little is known about the neuropathophysiology of binge-eating disorder (BED). Here, the evidence from neuroimaging, neurocognitive, genetics, and animal studies are reviewed to synthesize our current understanding of the pathophysiology of BED. Binge-eating disorder may be conceptualized as an impulsive/compulsive disorder, with altered reward sensitivity and food-related attentional biases. Neuroimaging studies suggest there are corticostriatal circuitry alterations in BED similar to those observed in substance abuse, including altered function of prefrontal, insular, and orbitofrontal cortices and the striatum. Human genetics and animal studies suggest that there are changes in neurotransmitter networks, including dopaminergic and opioidergic systems, associated with binge-eating behaviors. Overall, the current evidence suggests that BED may be related to maladaptation of the corticostriatal circuitry regulating motivation and impulse control similar to that found in other impulsive/compulsive disorders. Further studies are needed to understand the genetics of BED and how neurotransmitter activity and neurocircuitry function are altered in BED and how pharmacotherapies may influence these systems to reduce BED symptoms.

Food cue reactivity and craving predict eating and weight gain: a meta-analytic review

According to learning-based models of behavior, food cue reactivity and craving are conditioned responses that lead to increased eating and subsequent weight gain. However, evidence supporting this relationship has been mixed. We conducted a quantitative meta-analysis to assess the predictive effects of food cue reactivity and craving on eating and weight-related outcomes. Across 69 reported statistics from 45 published reports representing 3,292 participants, we found an overall medium effect of food cue reactivity and craving on outcomes (r = 0.33, p < 0.001; approximately 11% of variance), suggesting that cue exposure and the experience of craving significantly influence and contribute to eating behavior and weight gain. Follow-up tests revealed a medium effect size for the effect of both tonic and cue-induced craving on eating behavior (r = 0.33). We did not find significant differences in effect sizes based on body mass index, age, or dietary restraint. However, we did find that visual food cues (e.g. pictures and videos) were associated with a similar effect size to real food exposure and a stronger effect size than olfactory cues. Overall, the present findings suggest that food cue reactivity, cue-induced craving and tonic craving systematically and prospectively predict food-related outcomes. These results have theoretical, methodological, public health and clinical implications.