Current considerations regarding food addiction

Psychosocial risk and protective factors for youth problem behavior are associated with food addiction in the Generation Z

Objective

Food Addiction (FA) and other well-known risk behavior as substance misuse tend to co-occur and may share similar risk and protective factors. The aim of this study was to assess the association between the diagnosis/severity of FA and psychosocial domains typically related to risk behavior syndrome in a large, nationally representative community sample of Generation Z underage Italian students.

Method

The sample consisted of 8,755 students (3,623 from middle schools, 5,132 from high schools). A short version of the Yale Food Addiction Scale 2.0 was administered to evaluate FA. Risk and protective factors related to demographic, personality, behavior, and family variables were examined. Stepwise multivariate logistic and linear regressions were conducted.

Results

The prevalence of FA was 30.8%. Female gender, social anxiety and depression symptoms, social withdrawal risk, Internet gaming disorder, social media addiction, current substance use, social challenge engagement and experienced doxing boosted the chance of FA diagnosis, whereas eating fruit and vegetables, playing competitive sports and an average sleep duration of 7-8 h per night reduced these odds. FA severity was significantly and positively associated with trait impulsiveness, social anxiety and depressive symptoms, risk of social withdrawal, recent substance use, social media, and gaming addiction, doxing suffered and risky social challenges participation. Negative associations between the severity of FA and fruit and vegetable diet habits were found.

Conclusion

Our findings confirm that FA is widespread among Italian adolescents. The associations between the diagnosis and severity of FA and psychosocial risk factors for health, including, addictive and deviant behaviors related to digital misuse, suggest its belonging to the risk behavior constellation. Health promotion schemes based on a multicomponent strategy of intervention should consider the inclusion of FA and its psychosocial correlates.

Eating disorders and obesity: bridging clinical, neurobiological, and therapeutic perspectives

Eating disorders (EDs) and obesity are complex health conditions sharing various risk and maintenance factors, intensified in cases of comorbidity. This review explores the similarities and connections between these conditions, examining different facets from a multidisciplinary perspective, among them comorbidities, metabolic and psychological factors, neurobiological aspects, and management and therapy implications. We aim to investigate the common characteristics and complexities of weight and EDs and explore their interrelationships in individuals who experience both. The rising prevalence of EDs in people with obesity necessitates integrated approaches to study this comorbidity and to identify and analyze both common and distinct features of these conditions. This review may offer new opportunities for simultaneous prevention and management approaches, as well as future lines of research.

The Association between Grazing and Food Addiction: The Italian Version of the Repetitive Eating Questionnaire (Rep(Eat)-Q) and Its Relationships with Food Addiction Criteria

BACKGROUND

Among the dysfunctional eating behaviors associated with excessive food intake, a construct that is gaining increasing attention is grazing-the constant, continuous, compulsive, and repetitive consumption of small/moderate amounts of food. Furthermore, in some cases, grazing seems to indicate a dependence on food and/or eating. Currently, the Repetitive Eating Questionnaire (Rep(Eat)-Q) appears to be the only questionnaire that comprehensively measures grazing, including its repetitive and compulsive eating component. Therefore, in a sample of individuals with severe obesity, the objective of this study was twofold: (A) to evaluate the psychometric properties of the Italian version of the Rep(Eat)-Q, and (B) to analyze the association between grazing and food addiction (FA).

METHOD

A cross-sectional research design was used. A total of 402 inpatients with severe obesity (BMI > 35) were recruited. Participants underwent a series of questionnaires to investigate structural validity and convergent validity and association with FA criteria.

RESULTS

The factorial structure of the Rep(Eat)-Q is robust and showed fit indexes: CFI = 0.973; RMSEA = 0.074; 90%CI [0.056-0.091]; and SRMR = 0.029. Also, it exhibited good internal consistency and convergent validity. Furthermore, logistic regression analysis highlights a specific association between certain FA criteria and grazing.

CONCLUSIONS

The Rep(Eat)-Q can be considered to be a concise, robust, reliable, and statistically sound tool to assess repetitive eating, specifically grazing. Its strong psychometric properties offer significant advantages for both research and clinical applications. Furthermore, in a sample of individuals with severe obesity, the results suggest that individuals with problematic grazing exhibit a typical behavioral profile of subjects with FA, indicating that FA can manifest through problematic grazing as well.

Food addiction, hormones and blood biomarkers in humans: A systematic literature review

BACKGROUND

Food addiction may play a role in rising obesity rates in connection with obesogenic environments and processed food availability, however the concept of food addiction remains controversial. While animal studies show evidence for addictive processes in relation to processed foods, most human studies are psychologically focussed and there is a need to better understand evidence for biological mechanisms of food addiction in humans. Several key hormones are implicated in models of food addiction, due to their key roles in feeding, energy metabolism, stress and addictive behaviours. This systematic literature review examines evidence for relationships between food addiction, hormones and other blood biomarkers.

METHODS

A series of literature searches was performed in Scopus, PsychInfo, MedLine, ProQuest, CINAHL and Web of Science. A total of 3111 articles were found, of which 1045 were duplicates. Articles were included if they contained a psychometric measurement of food addiction, such as the Yale Food Addiction Scale, as well as addressed the association between FA and hormones or blood biomarkers in humans. Articles were assessed for eligibility by two independent reviewers.

RESULTS

Sixteen studies were identified that examined relationships between food addiction and blood biomarkers, published between 2015 and 2021. Significant findings were reported for leptin, ghrelin, cortisol, insulin and glucose, oxytocin, cholesterol, plasma dopamine, thyroid stimulating hormone (TSH), haemoglobin A1c (HbA1c), triglyceride (TG), amylin, tumour necrosis factor alpha (TNF- α) and cholecystokinin (CCK). Methodological issues included small sample sizes and variation in obesity status, sex and mental health-related comorbidities. Due to methodological limitations, definite connections between FA, hormones and other blood biomarkers cannot yet be determined.

CONCLUSION

This systematic review identified preliminary evidence linking FA symptoms to hormones and other blood biomarkers related to feeding, addiction, and stress. However, due to the small number of studies and methodological limitations, further research is needed to evaluate biopsychosocial models of FA and to resolve controversies.

Ghrelin/GHS-R1A antagonism in memory test and its effects on central molecular signaling involved in addiction in rats

Central ghrelin signaling seems to play important role in addiction as well as memory processing. Antagonism of the growth hormone secretagogue receptor (GHS-R1A) has been recently proposed as a promising tool for the unsatisfactory drug addiction therapy. However, molecular aspects of GHS-R1A involvement in specific brain regions remain unclear. The present study demonstrated for the first time that acute as well as subchronic (4 days) administration of the experimental GHS-R1A antagonist JMV2959 in usual intraperitoneal doses including 3 mg/kg, had no influence on memory functions tested in the Morris Water Maze in rats as well as no significant effects on the molecular markers linked with memory processing in selected brain areas in rats, specifically on the β-actin, c-Fos, two forms of the calcium/calmodulin-dependent protein kinase II (CaMKII, p-CaMKII) and the cAMP-response element binding protein (CREB, p-CREB), within the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), dorsal striatum, and hippocampus (HIPP). Furthermore, following the methamphetamine intravenous self-administration in rats, the 3 mg/kg JMV2959 pretreatment significantly reduced or prevented the methamphetamine-induced significant decrease of hippocampal β-actin and c-Fos as well as it prevented the significant decrease of CREB in the NAC and mPFC. These results imply, that the GHS-R1A antagonist/JMV2959 might reduce/prevent some of the memory-linked molecular changes elicited by methamphetamine addiction within brain structures associated with memory (HIPP), reward (NAc), and motivation (mPFC), which may contribute to the previously observed significant JMV2959-induced reduction of the methamphetamine self-administration and drug-seeking behavior in the same animals. Further research is necessary to corroborate these results.

An addiction-based digital weight loss intervention: A multi-centre randomized controlled trial

OBJECTIVE

This randomized clinical trial tested the effectiveness of an addiction-based digital weight-loss intervention, focusing on withdrawal/abstinence from self-identified problem foods, snacking and excessive amounts at meals, and discomfort displacement, with and without coaching, compared to an in-person, multi-disciplinary, care model among adolescents with obesity. We hypothesized that the digital intervention with coaching would yield greater weight loss and lower delivery burden than the standard clinical arm, and greater participant engagement than the digital arm without coaching.

METHODS

Adolescents were randomized to app intervention, with or without coaching, or in-person multidisciplinary obesity intervention for 6 months. The primary outcome was change in %BMIp95 at weeks 12 and 24. A mixed-effects linear regression model was used to assess the association between change in %BMIp95 and intervention arm. We were also interested in assessing delivery burden, participant engagement and evaluating the relationships between weight change and demographic characteristics, mood, executive function and eating behaviours.

RESULTS

All adolescents (n = 161; BMI ≥95th%, age 16 ± 2.5 year; 47% Hispanic, 65% female, 59% publicly insured) lost weight over 24-weeks (-1.29%, [-1.82, -0.76], p < 0.0001), with no significant weight loss difference between groups (p = 0.3). Girls lost more weight than boys, whereas binge eating behaviour at baseline was associated with increase in %BMIp95 when controlling for other covariates. There was no association between ethnicity, mood, timing of intervention in relation to the pandemic, or executive function and change in %BMIp95 .

CONCLUSIONS

Contrary with our hypothesis, our results showed no difference in the change in BMI status between treatment arms. Since efficacy of this digital intervention was not inferior to in-person, multi-disciplinary care, this could offer a reasonable weight management option for clinicians, based on youth and family specific characteristics, such as accessibility, resources, and communication styles.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT035008353.

Potential Biological Markers and Treatment Implications for Binge Eating Disorder and Behavioral Addictions

The reward system is highly relevant to behavioral addictions such as gambling disorder (GD), internet gaming disorder (IGD), and food addiction/binge eating disorder (FA/BED). Among other brain regions, the ventral striatum (VS) has been implicated in reward processing. The main objective of the present state-of-the-art review was to explore in depth the specific role of the VS in GD, IGD and FA/BED, understanding it as a possible biomarker of these conditions. Studies analyzing brain changes following interventions for these disorders, and especially those that had explored possible treatment-related changes in VS, are discussed. More evidence is needed on how existing treatments (both pharmacological and psychobehavioral) for behavioral addictions affect the activation of the VS and related circuitry.

Associations Between Food Addiction and Substance-Use Disorders: A Critical Overview of their Overlapping Patterns of Consumption

Purpose of Review

Research on patterns of overconsumption in individuals with food addiction (FA) has focused largely on binge eating. However, compulsive overeating can be varied and dimensional. This review focuses on the similarities between the patterns of consumption in FA and in other clinically established substance-use disorders, such as alcohol and nicotine dependence. It also highlights features that make FA unique to other addiction disorders.

Recent Findings

Overall, there is substantial evidence that binge-like overconsumption is a characteristic of various substance-use and eating disorders. Likewise, it appears that different overeating patterns can reflect addictive-like eating. One pattern may be compulsive grazing — defined as the repetitive inability to resist consumption of small amounts of food.

Summary

This review adds to the increasingly compelling picture that FA and binge-eating disorder are unique conditions, and that FA resembles other substance-use disorders. We conclude that a variety of overeating patterns can reflect addictive eating behaviours in vulnerable individuals, one of which may be compulsive grazing.

Adult attachment anxiety is associated with night eating syndrome in UK and US-based samples: Two cross-sectional studies

Previous research has shown that "attachment anxiety" is a robust predictor of disinhibited eating behaviours and that this relationship is underpinned by difficulties in managing emotion. Night eating syndrome (NES), a proposed eating disorder characterized by evening hyperphagia, nocturnal awakenings to eat, and morning anorexia, is also associated with eating to manage emotion. Across two studies (N = 276 &N = 486), we considered a relationship between attachment anxiety and NES. In Study 1, we hypothesised (pre-registered) that attachment anxiety would predict NES score and that this relationship would be mediated by disinhibited eating. Participants were asked to complete questionnaire measures of attachment orientation, disinhibited eating (emotional and uncontrolled eating) and NES. Our parallel mediation model confirmed a direct relationship between attachment anxiety and NES (p < .001) and showed an indirect path via both emotional (95% CI: 0.15-0.63) and uncontrolled eating (95% CI: 0.001-0.36). In Study 2, we showed that fear of negative evaluation of eating significantly mediated a reversed relationship between attachment anxiety and NES (95% CI: 0.02-0.04). Finally, across both studies we used a novel tool to assess "eating to cope". We showed a relationship with emotional eating but failed to show a robust relationship with NES. Attachment orientation may represent a potential intervention target for night eating syndrome. Future research should consider a longitudinal approach to strengthen our understanding of directionality amongst these factors.

The Relationship of Food Addiction With Other Eating Pathologies and Impulsivity: A Case-Control Study

The concept of food addiction (FA) has become central in recent years in understanding the psychological etiology of obesity. In this matched case-control study from Turkey, it was aimed to examine the prevalence of FA and related risk factors in four consecutive body mass index (BMI) categories. The case group consisted of pre-operative bariatric surgery patients with BMI over 35.0 kg/m2 (n = 40) and the control group was composed of age- and gender- matching individuals from the other categories, namely obese (n = 35), overweight (n = 40), and normal weight (n = 40). The Yale Food Addiction Scale (YFAS) and a standardized clinical interview using the DSM-5 substance use disorders criteria adopted for FA, the Eating Disorder Examination Questionnaire (EDEQ) and the Barratt Impulsivity Scale (BIS-11) were used as assessment instruments. It was found that FA was significantly associated with more serious eating pathologies, more frequent weight-cycling and earlier onset of dieting, higher impulsivity, and higher BMI. Motor and total impulsivity scores showed a positive albeit week correlation with the severity of FA but no significant correlation with BMI, indicating a relationship between impulsivity and weight gain in some but not all individuals. The severity of FA predicted the increase in BMI. Our findings suggest that FA is associated with weight gain in a group of individuals, plausibly through impulsive overeating. Emphasis on FA and its clinical implications such as addiction-based treatments may improve outcomes in obesity and facilitate health promotion.

Highly processed food addiction: A concept analysis

AIM

This concept analysis aims to clarify the highly processed food addiction (HPFA) concept and discuss its implications for treating obesity.

BACKGROUND

Emerging empirical evidence suggests addictive-like eating may contribute to obesity in some individuals, increasing interest in HPFA's role in obesity. Clarifying the HPFA concept will aid in developing individualized interventions for patients with obesity and HPFA.

DESIGN

This concept analysis followed Walker and Avant's approach. The case studies are of participants in a study that included individuals with and without HPFA (Yale Food Addiction Scale 2.0-diagnosed).

DATA SOURCE

We searched PubMed, CINAHL, PsychInfo, and Ebscohost databases. Keywords were "food addiction" and "food addiction concept."

REVIEW METHODS

Criteria included recent reviews and empirical studies that measured HPFA and focused on HPFA characteristics and/or treatment implications.

RESULTS

The model case displayed all 11-substance use disorder (SUD) symptoms and clinical significance, supporting a severe HPFA diagnosis. The contrary case was negative for all YFAS 2.0 symptoms and clinical significance and did not eat compulsively or experience cravings. The borderline case met the minimum symptom criteria for severe HPFA but not clinical significance. Clinical interviews may help determine whether such individuals truly exhibit addictive-like eating behaviors.

CONCLUSIONS

Growing empirical evidence and our case studies support the HPFA concept and the utility of the YFAS/YFAS 2.0 for identifying a distinct subset of individuals with overweight/obesity who may benefit from interventions developed to treat established SUDs. Future research should examine HPFA separately and in relation to obesity and eating disorders and include longitudinal studies and gender-balanced samples.

Peter JV. Sugars and Sweet Taste: Addictive or Rewarding?

The notion of food "addiction" often focuses on the overconsumption of sweet tasting foods or so-called sugar "addiction". In the extreme, some have suggested that sugar and sweet tastes elicit neural and behavioral responses analogous to those observed with drugs of abuse. These concepts are complicated by the decades long uncertainty surrounding the validity and reproducibility of functional magnetic resonance imaging (fMRI) methodologies used to characterize neurobiological pathways related to sugar and sweet taste stimuli. There are also questions of whether sweet taste or post-ingestion metabolic consequences of sugar intake would lead to addiction or excessive caloric intake. Here, we present a focused narrative review of literature related to the reward value of sweet taste which suggests that reward value can be confounded with the construct of "addictive potential". Our review seeks to clarify some key distinctions between these constructs and questions the applicability of the addiction construct to human over-eating behaviors. To adequately frame this broad discussion requires the flexibility offered by the narrative review paradigm. We present selected literature on: techniques used to link sugar and sweet tastes to addiction neurobiology and behaviors; sugar and sweet taste "addiction"; the relationship of low calorie sweetener (LCS) intake to addictive behaviors and total calorie intake. Finally, we examined the reward value of sweet tastes and contrasted that with the literature describing addiction. The lack of reproducibility of fMRI data remains problematic for attributing a common neurobiological pathway activation of drugs and foods as conclusive evidence for sugar or sweet taste "addiction". Moreover, the complicated hedonics of sweet taste and reward value are suggested by validated population-level data which demonstrate that the consumption of sweet taste in the absence of calories does not increase total caloric intake. We believe the neurobiologies of reward value and addiction to be distinct and disagree with application of the addiction model to sweet food overconsumption. Most hypotheses of sugar "addiction" attribute the hedonics of sweet foods as the equivalent of "addiction". Further, when addictive behaviors and biology are critically examined in totality, they contrast dramatically from those associated with the desire for sweet taste. Finally, the evidence is strong that responses to the palatability of sweets rather than their metabolic consequences are the salient features for reward value. Thus, given the complexity of the controls of food intake in humans, we question the usefulness of the "addiction" model in dissecting the causes and effects of sweet food over-consumption.

Temporal discounting as a candidate behavioral marker of obesity

Although obesity is a result of processes operating at multiple levels, most forms result from decision-making behavior. The aim of this review was to examine the candidacy of temporal discounting (TD) (i.e. the reduction in the value of a reinforcer as a function of the delay to its receipt) as a behavioral marker of obesity. For this purpose, we assessed whether TD has the ability to: identify risk for obesity development, diagnose obesity, track obesity progression, predict treatment prognosis/outcomes, and measure treatment effectiveness. Three databases (Pubmed, PsycINFO, and Web of Science) were searched using a combination of terms related to TD and obesity. A total of 153 papers were reviewed. Several areas show strong evidence of TD's predictive utility as a behavioral marker of obesity (e.g., distinguishing obese from non obese). However, other areas have limited and/or mixed evidence (e.g., predicting weight change). Given the positive relationship for TD in the majority of domains examined, further consideration for TD as a behavioral marker of obesity is warranted.

DSM-5 eating disorder prevalence, gender differences, and mental health associations in United States military veterans

OBJECTIVE

Little is known about prevalence estimates of new and revised DSM-5 eating disorders diagnoses in general, and especially among high-risk, underserved and diverse eating disorder populations. The aim of the current study was to determine prevalence, gender differences and correlates of DSM-5 eating disorders in veterans.

METHOD

Iraq and Afghanistan war era veterans (N = 1,121, 51.2% women) completed the Eating Disorder Diagnostic Scale-5 and validated measures of eating pathology and mental health between July 2014 and September 2019.

RESULTS

Overall more women than men (32.8% vs. 18.8%, p < .001) reported symptoms consistent with a DSM-5 eating disorder. Prevalence estimates (women vs. men) for the specific diagnoses were: Anorexia Nervosa (AN; 0.0% vs. 0.0%), Bulimia Nervosa (BN; 6.1% vs. 3.5%), Binge-Eating Disorder (BED; 4.4% vs. 2.9%), Atypical AN (AAN; 13.6% vs. 4.9%), Subclinical BN (0.0% vs. 0.2%), Subclinical BED (1.4% vs. 0.6%), Purging Disorder (2.1% vs. 0.7%), and Night Eating Syndrome (NES; 5.2% vs. 6.0%). Women were more likely to have BN or AAN, and there was no difference for BED or NES among genders. The eating disorder group had a higher mean BMI, and significantly greater eating pathology and mental health symptoms than the non-eating disorder group.

DISCUSSION

Approximately one-third of women, and one-fifth of men, reported symptoms consistent with a DSM-5 eating disorder diagnosis. These high prevalence estimates across genders, and associated mental health concerns, suggest an urgent need to better understand and address eating disorders in military and veteran populations.

Atypical Anorexia Nervosa, not so atypical after all: Prevalence, correlates, and clinical severity among United States military Veterans

OBJECTIVE

DSM-5 Atypical Anorexia Nervosa (AAN), a new eating disorder diagnosis, presents similarly to Anorexia Nervosa (AN) in the absence of severe underweight. The prevalence of AAN and other DSM-5 eating disorders was estimated in a sample of Veterans. Sociodemographic, mental health, and eating behavior correlates were examined.

METHOD

Iraq and Afghanistan war era Veterans (N = 1137, 51.6% female) completed the Eating Disorder Diagnostic Scale-5 for probable AAN diagnosis, and validated measures of eating pathology and mental health, between February 2016 and October 2019. Multivariate analyses compared Veterans with AAN to those with and without any DSM-5 eating disorder.

RESULTS

Among completers, 13.6% of women and 4.9% of men in the sample met criteria for probable AAN and 19.2% of women and 13.9% of men for another eating disorder. Mean age was 41 years, and on average BMIs were classified as overweight (BMI = 28.8, SD = 5.6) despite being at least 10% lower than their lifetime highest weight. Two-thirds reported dietary restraint on more than half the days in the past month. On measures of mental health, the AAN group had worse functioning than the no eating disorder group, similar functioning to Veterans with Binge Eating Disorder (BED), and better functioning than Veterans with Bulimia Nervosa (BN).

DISCUSSION

Results support AAN as a highly prevalent and clinically significant diagnosis. Findings highlight the need to identify and address eating disorders, particularly other specified eating disorders not meeting criteria for AN, BN, or BED, in active military and Veteran, and other high-risk and underserved, populations.

Food addiction comorbid to mental disorders: A nationwide survey and register-based study

OBJECTIVE

Substance use disorder is highly prevalent among individuals with mental disorders. However, it remains largely unknown whether this is also the case for "food addiction"-a phenotype characterized by an addiction-like attraction to predominantly highly processed foods with a high content of refined carbohydrates and fat. Therefore, the primary aim of this study was to estimate the weighted prevalence of food addiction among individuals with mental disorders.

METHOD

A total of 5,000 individuals aged 18-62 were randomly drawn from eight categories of major mental disorders from the Danish Psychiatric Central Research Register and invited to participate in an online questionnaire-based survey, which included the Yale Food Addiction Scale 2.0. Data on health care and sociodemographics from the Danish registers were linked to all invitees-enabling comprehensive attrition analysis and calculation of the weighted prevalence of food addiction.

RESULTS

A total of 1,394 (27.9%) invitees participated in the survey. Across all diagnostic categories, 23.7% met the criteria for food addiction. The weighted prevalence of food addiction was highest among individuals with eating disorders (47.7%, 95%CI: 41.2-54.2), followed by affective disorders (29.4%, 95%CI: 22.9-36.0) and personality disorders (29.0%, 95%CI: 22.2-35.9). When stratifying on sex, the prevalence of food addiction was higher among women in most diagnostic categories.

DISCUSSION

Food addiction is highly prevalent among individuals with mental disorders, especially in those with eating disorders, affective disorders and personality disorders. Food addiction may be an important target for efforts aimed at reducing obesity among individuals with mental disorders.

Brain-Gut-Microbiome Interactions and Intermittent Fasting in Obesity

The obesity epidemic and its metabolic consequences are a major public health problem both in the USA and globally. While the underlying causes are multifactorial, dysregulations within the brain–gut–microbiome (BGM) system play a central role. Normal eating behavior is coordinated by the tightly regulated balance between intestinal, extraintestinal and central homeostatic and hedonic mechanisms, resulting in stable body weight. The ubiquitous availability and marketing of inexpensive, highly palatable and calorie-dense food has played a crucial role in shifting this balance towards hedonic eating through both central (disruptions in dopaminergic signaling) and intestinal (vagal afferent function, metabolic toxemia, systemic immune activation, changes to gut microbiome and metabolome) mechanisms. The balance between homeostatic and hedonic eating behaviors is not only influenced by the amount and composition of the diet, but also by the timing and rhythmicity of food ingestion. Circadian rhythmicity affects both eating behavior and multiple gut functions, as well as the composition and interactions of the microbiome with the gut. Profound preclinical effects of intermittent fasting and time restricted eating on the gut microbiome and on host metabolism, mostly demonstrated in animal models and in a limited number of controlled human trials, have been reported. In this Review, we will discuss the effects of time-restricted eating on the BGM and review the promising effects of this eating pattern in obesity treatment.

Food Addiction and Tobacco Use Disorder: Common Liability and Shared Mechanisms

As food addiction is being more commonly recognized within the scientific community, parallels can be drawn between it and other addictive substance use disorders, including tobacco use disorder. Given that both unhealthy diets and smoking are leading risk factors for disability and death, a greater understanding of how food addiction and tobacco use disorder overlap with one another is necessary. This narrative review aimed to highlight literature that investigated prevalence, biology, psychology, and treatment options of food addiction and tobacco use disorder. Published studies up to August 2020 and written in English were included. Using a biopsychosocial lens, each disorder was assessed together and separately, as there is emerging evidence that the two disorders can develop concurrently or sequentially within individuals. Commonalities include but are not limited to the dopaminergic neurocircuitry, gut microbiota, childhood adversity, and attachment insecurity. In addition, the authors conducted a feasibility study with the purpose of examining the association between food addiction symptoms and tobacco use disorder among individuals seeking tobacco use disorder treatment. To inform future treatment approaches, more research is necessary to identify and understand the overlap between the two disorders.

Longitudinal Changes in Food Addiction Symptoms and Body Weight among Adults in a Behavioral Weight-Loss Program

Interest in food addiction (FA) has increased, but little is known about its clinical implications or potential treatments. Using secondary analyses from a randomized controlled trial, we evaluated the associations between changes in FA, body weight, and “problem food” consumption during a 22-month behavioral weight-loss program consisting of an initial four-month in-person intervention, 12-month extended-care, and six-month follow-up (n = 182). Food addiction was measured using the Yale Food Addiction Scale. “Problem foods” were identified from the literature and self-reporting. Multilevel modeling was used as the primary method of analysis. We hypothesized that reductions in problem food consumption during the initial treatment phase would be associated with long-term (22-month) FA reductions. As expected, we found that reductions in problem foods were associated with greater initial reductions in FA symptoms; however, they were also associated with a sharper rebound in symptoms over time (p = 0.016), resulting in no significant difference at Month 22 (p = 0.856). Next, we hypothesized that long-term changes in FA would be associated with long-term changes in body weight. Although both FA and weight decreased over time (ps < 0.05), month-to-month changes in FA were not associated with month-to-month changes in weight (p = 0.706). Instead, higher overall FA (i.e., mean scores over the course of the study) were associated with less weight loss (p = 0.008) over time. Finally, we hypothesized that initial reductions in problem food consumption would be associated with long-term reductions in weight, but this relationship was not significant (ps > 0.05). Given the complexity of the findings, more research is needed to identify interventions for long-term changes in FA and to elucidate the associations between problem foods, FA, and weight.

Brain-gut-microbiome interactions in obesity and food addiction

Normal eating behaviour is coordinated by the tightly regulated balance between intestinal and extra-intestinal homeostatic and hedonic mechanisms. By contrast, food addiction is a complex, maladaptive eating behaviour that reflects alterations in brain-gut-microbiome (BGM) interactions and a shift of this balance towards hedonic mechanisms. Each component of the BGM axis has been implicated in the development of food addiction, with both brain to gut and gut to brain signalling playing a role. Early-life influences can prime the infant gut microbiome and brain for food addiction, which might be further reinforced by increased antibiotic usage and dietary patterns throughout adulthood. The ubiquitous availability and marketing of inexpensive, highly palatable and calorie-dense food can further shift this balance towards hedonic eating through both central (disruptions in dopaminergic signalling) and intestinal (vagal afferent function, metabolic endotoxaemia, systemic immune activation, changes to gut microbiome and metabolome) mechanisms. In this Review, we propose a systems biology model of BGM interactions, which incorporates published reports on food addiction, and provides novel insights into treatment targets aimed at each level of the BGM axis.

Food Addiction Is Associated with Binge Eating and Psychiatric Distress among Post-Operative Bariatric Surgery Patients and May Improve in Response to Cognitive Behavioural Therapy

The current study examined clinical correlates of food addiction among post-operative bariatric surgery patients, compared the clinical characteristics of patients with versus without food addiction, and examined whether a brief telephone-based cognitive behavioural therapy (Tele-CBT) intervention improves food addiction symptomatology among those with food addiction. Participants (N = 100) completed measures of food addiction, binge eating, depression, and anxiety 1 year following bariatric surgery, were randomized to receive either Tele-CBT or standard bariatric post-operative care, and then, repeated the measure of food addiction at 1.25 and 1.5 years following surgery. Thirteen percent of patients exceeded the cut-off for food addiction at 1 year post-surgery, and this subgroup of patients reported greater binge eating characteristics and psychiatric distress compared to patients without food addiction. Among those with food addiction, Tele-CBT was found to improve food addiction symptomatology immediately following the intervention. These preliminary findings suggest that Tele-CBT may be helpful, at least in the short term, in improving food addiction symptomatology among some patients who do not experience remission of food addiction following bariatric surgery; however, these findings require replication in a larger sample.

Food Reward and Food Choice. An Inquiry Through The Liking and Wanting Model

What if consumers are getting obese because eating less calories is more difficult for persons that have a higher pleasure and desire towards food (Ikeda et al., 2005) and food companies do not help given only a two extreme option choice to satisfy their needs (i.e., low calories vs. high calories or healthy vs. unhealthy)? Reward systems are being described with a new conceptual approach where liking—the pleasure derived from eating a given food—and wanting—motivational value, desire, or craving—can be seen as the significant forces guiding eating behavior. Our work shows that pleasure (liking), desire (wanting), and the interaction between them influence and are good predictors of food choice and food intake. Reward responses to food are closely linked to food choice, inducing to caloric overconsumption. Based on the responses given to a self-administered questionnaire measuring liking and wanting attitudes, we found three different segments named ‘Reward lovers,’ ‘Half epicurious,’ and ‘Non indulgents’. Their behavior when choosing food is quite different. Results show differential effects on caloric consumption depending on segments. The introduction of more food choices that try to balance their content is a win-win strategy for consumers, companies, and society.

The Effect of a Food Addiction Explanation Model for Weight Control and Obesity on Weight Stigma

There is increasing scientific and public support for the notion that some foods may be addictive, and that poor weight control and obesity may, for some people, stem from having a food addiction. However, it remains unclear how a food addiction model (FAM) explanation for obesity and weight control will affect weight stigma. In two experiments (N = 530 and N = 690), we tested the effect of a food addiction explanation for obesity and weight control on weight stigma. In Experiment 1, participants who received a FAM explanation for weight control and obesity reported lower weight stigma scores (e.g., less dislike of ‘fat people’, and lower personal willpower blame) than those receiving an explanation emphasizing diet and exercise (F_(4,525) = 7.675, p = 0.006; and F_(4,525) = 5.393, p = 0.021, respectively). In Experiment 2, there was a significant group difference for the dislike of ‘fat people’ stigma measure (F_(5,684) = 5.157, p = 0.006), but not for personal willpower weight stigma (F_(5,684) = 0.217, p = 0.81). Participants receiving the diet and exercise explanation had greater dislike of ‘fat people’ than those in the FAM explanation and control group (p values < 0.05), with no difference between the FAM and control groups (p > 0.05). The FAM explanation for weight control and obesity did not increase weight stigma and resulted in lower stigma than the diet and exercise explanation that attributes obesity to personal control. The results highlight the importance of health messaging about the causes of obesity and the need for communications that do not exacerbate weight stigma.

"Making weight" during military service is related to binge eating and eating pathology for veterans later in life

PURPOSE

"Making weight" behaviors are unhealthy weight control strategies intended to reduce weight in an effort to meet weight requirements. This study aimed to examine a brief measure of making weight and to investigate the relationship between making weight and weight, binge eating, and eating pathology later in life.

METHODS

Participants were veterans [N = 120, mean age 61.7, mean body mass index (BMI) 38.0, 89.2% male, 74.2% Caucasian] who were overweight/obese and seeking weight management treatment. Participants completed the making weight inventory (MWI), a measure of making weight behaviors engaged in during military service, and validated measures of eating behavior. Analyses compared participants who engaged in at least one making weight behavior (MWI+) versus those who did not (MWI-).

RESULTS

The MWI had good internal consistency. One-third of participants were MWI+ and two-thirds were MWI-. The most frequently reported behavior was excessive exercise, reported in one-quarter of the sample, followed by fasting/skipping meals, sauna/rubber suit, laxatives, diuretics, and vomiting. MWI+ participants were significantly more likely to be in a younger cohort of veterans, to be an ethnic/racial minority, and to engage in current maladaptive eating behaviors, including binge eating, vomiting, emotional eating, food addiction, and night eating, compared to the MWI- group. Groups did not differ on BMI.

CONCLUSIONS

One-third of veterans who were overweight/obese screened positive for engaging in making weight behaviors during military service. Findings provide evidence that efforts to "make weight" are related to binge eating and eating pathology later in life. Future research and clinical efforts should address how to best eliminate unhealthy weight control strategies in military service while also supporting healthy weight management efforts.

Food Addiction in Eating Disorders and Obesity: Analysis of Clusters and Implications for Treatment

Food addiction (FA) has been associated with greater psychopathology in individuals with eating disorders (ED) and obesity (OBE). The current study aims to provide a better phenotypic characterization of the FA construct by conducting a clustering analysis of FA in both conditions (ED and OBE). The total sample was comprised of 234 participants that scored positive on the Yale Food Addiction Scale 2.0. (YFAS-2) (119 bulimia nervosa (BN), 50 binge eating disorder (BED), 49 other specified feeding or eating disorder (OSFED) and 16 OBE). All participants completed a comprehensive battery of questionnaires. Three clusters of FA participants were identified. Cluster 1 (dysfunctional) was characterized by the highest prevalence of OSFED and BN, the highest ED severity and psychopathology, and more dysfunctional personality traits. Cluster 2 (moderate) showed a high prevalence of BN and BED and moderate levels of ED psychopathology. Finally, cluster 3 (adaptive) was characterized by a high prevalence of OBE and BED, low levels of ED psychopathology, and more functional personality traits. In conclusion, this study identified three distinct clusters of ED-OBE patients with FA and provides some insight into a better phenotypic characterization of the FA construct when considering psychopathology, personality and ED pathology. Future studies should address whether these three food addiction categories are indicative of therapy outcome.

Food Addiction Is Associated with Irrational Beliefs via Trait Anxiety and Emotional Eating

Irrational beliefs (IB) are believed, in cognitive behavioral therapies, to be a prime cause of psychopathologies including anxiety, depression, problem eating, and alcohol misuse. "Food addiction" (FA), which has been modeled on diagnostic criteria for substance use disorder, and emotional eating (EE) have both been implicated in the rise in overweight and obesity. Both FA and EE are associated with anxiety. Thus, in the present study, the hypothesis that IB is associated with FA and with EE was tested. Furthermore, possible mediation of these relationships by trait anxiety and depression (and EE for IB and FA) was examined. The responses of 239 adult participants to questionnaires measuring FA, IB, EE, depression, trait anxiety, and anthropometrics were recorded. The results revealed that IB was significantly positively correlated with FA and EE (and depression and trait anxiety). Furthermore, only EE mediated the effect of IB on FA and this was not moderated by BMI. Finally, trait anxiety (but not depression) mediated the effect of IB on EE. Exploratory analysis revealed a significant serial mediation such that IB predicted higher FA via elevated trait anxiety and emotional eating in that order. The results of this study suggest that IB may be a source of the anxiety that is associated with EE and FA and suggest that clinicians may find IB a target for treatment of those persons who report experiences of EE and FA. IB may play a role in food misuse that leads to elevated BMI.

Neuroanatomical correlates of food addiction symptoms and body mass index in the general population

The food addiction model suggests neurobiological similarities between substance-related and addictive disorders and obesity. While structural brain differences have been consistently reported in these conditions, little is known about the neuroanatomical correlates of food addiction. We therefore aimed to determine whether symptoms of food addiction related to body mass index (BMI), personality, and brain structure in a large population-based sample. Participants of the LIFE-Adult study (n = 625; 20-59 years old, 45% women) answered the Yale Food Addiction Scale (YFAS) and further personality measures, underwent anthropometric assessments and high-resolution 3T-neuroimaging. A higher YFAS symptom score correlated with higher BMI, eating behavior traits, neuroticism, and stress. Higher BMI predicted significantly lower thickness of (pre)frontal, temporal and occipital cortex and increased volume of left nucleus accumbens. In a whole-brain analysis, YFAS symptom score was not associated with significant differences in cortical thickness or subcortical gray matter volumes. A hypothesis-driven Bayes factor analysis suggested a small, additional contribution of YFAS symptom score to lower right lateral orbitofrontal cortex thickness over the effect of BMI. Our study indicates that symptoms of food addiction do not account for the major part of the structural brain differences associated with BMI in the general population. Yet, symptoms of food addiction might explain additional variance in orbitofrontal cortex, a hub area of the reward network. Longitudinal studies implementing both anatomical and functional MRI could further disentangle the neural mechanisms of addictive eating behaviors.

Food addiction, in obese patients seeking bariatric surgery, is associated with higher prevalence of current mood and anxiety disorders and past mood disorders

The current cross-sectional study investigates the prevalence of the food addiction (FA) phenotype and its association with psychiatric disorders in bariatric surgery candidates. It also investigates the eating behavior characteristics associated with FA and the association between FA and loss of control over specific foods high in sugar, salt and/or fat. We included 128 bariatric surgery candidates and we assessed FA (YFAS 2.0), mood and anxiety disorders, suicidality, eating disorders (current bulimia nervosa and current anorexia nervosa), alcohol and tobacco use disorders (MINI 5.0.0, beck depression inventory, AUDIT, Fagerström Test for Nicotine Dependence) and eating behavior (DEBQ). Prevalence of FA in our sample was 25%. FA was significantly associated with higher prevalence of current mood and anxiety disorders and past mood disorders, higher current suicidality but not with eating disorders and alcohol use disorder. FA was significantly associated with higher emotional eating, and with loss of control over consumption of foods high in fat, sugar and/or salt, but not of fruits, vegetables or grain products. Our results provide arguments for considering psychiatric disorders and suicidality in FA and for considering FA as an addictive disorder in obese patients, with many risk factors in common with other addictions.

Component Model of Addiction Treatment: A Pragmatic Transdiagnostic Treatment Model of Behavioral and Substance Addictions

Behavioral addictions such as gambling, video games, sex, and shopping share many clinical features with substance use addictions including etiology, course, and neurobiology. Yet, the treatment of behavioral and substance use addictions tends to be separated. However, we argue that a more effective and efficient treatment approach is to conceptualize behavioral and substance use addictions as different expressions of a common underlying disorder and, in treatment, to address the underlying mechanisms common to both. To this end, the article presents a developing transdiagnostic treatment model of addictions that targets underlying similarities between behavioral and substance use addictions, called the component model of addiction treatment (CMAT). The CMAT is transdiagnostic in that it can be used in the treatment of both behavioral and substance use addictions. It is pragmatic in that it targets component vulnerabilities, which are enduring, yet malleable, individual psychological, cognitive, and neurobiological characteristics that are common to all addictive disorders and have been demonstrated to be modifiable. A working model of CMAT is presented, including proposed component vulnerabilities: lack of motivation, urgency, maladaptive expectancies, deficits in self-control, deficits in social support, and compulsivity, as well as their potential intervention possibilities. Future directions and potential implications of the CMAT are discussed.

Does food addiction contribute to excess weight among clinic patients seeking weight reduction? Examination of the Modified Yale Food Addiction Survey

BACKGROUND

Despite controversy surrounding the construct of food addiction, its relationship with obesity and the validity of the Yale Food Addiction Scale (YFAS), have become emerging fields of study. No prior research has examined the prevalence and correlates of food addiction, and validation of the Modified Yale Food Addiction Scale (mYFAS), in a non-research based weight management clinic setting.

OBJECTIVE

The current study sought to examine the validity of a brief version of the Yale Food Addiction Scale in weight loss seeking patients, and to determine whether food addiction contributes to excess weight in this patient population.

PARTICIPANTS

The sample consisted of 126 Veterans with overweight/obesity who attended an orientation session for a weight management program. Participants (mean age = 61.8 years, mean BMI = 38.0, male = 89.7%, Caucasian = 76.0%) completed questionnaires related to food addiction, weight and eating, and mental health and behavior.

RESULTS

Ten percent of the sample met diagnostic threshold for food addiction. Correlational analysis revealed that food addiction was significantly and highly correlated with BMI, emotional eating, night eating and screens for depression and insomnia (p's < 0.001); significantly correlated with eating pathology, and screening for PTSD (p's < 0.05); and inversely correlated with screening for alcohol use disorders (p < 0.01). The prevalence of food addiction was significantly higher in participants with Binge Eating Disorder (75%) compared to participants without (5.4%; p < 0.001). Food addiction uniquely accounted for 15% of the variance of BMI, almost three times more than general eating disorder pathology.

DISCUSSION

This study provides further evidence for the validity of the mYFAS, and clinical significance of the food addiction construct among weight loss seeking patients in non-research based weight management settings. Findings confirm that food addiction contributes to excess weight among clinic patients seeking weight reduction above and beyond the effects of disordered eating. It is recommended that clinicians and researchers consider an addiction framework for addressing comorbid overweight and food addiction among afflicted individuals seeking weight loss.

Binge eating disorder and morbid obesity are associated with lowered mu-opioid receptor availability in the brain

Both morbid obesity and binge eating disorder (BED) have previously been linked with aberrant brain opioid function. Behaviorally these two conditions are however different suggesting also differences in neurotransmitter function. Here we directly compared mu-opioid receptor (MOR) availability between morbidly obese and BED subjects. Seven BED and nineteen morbidly obese (non-BED) patients, and thirty matched control subjects underwent positron emission tomography (PET) with MOR-specific ligand [¹¹C]carfentanil. Both subjects with morbid obesity and BED had widespread reduction in [¹¹C]carfentanil binding compared to control subjects. However, there was no significant difference in brain MOR binding between subjects with morbid obesity and BED. Thus, our results indicate that there is common brain opioid abnormality in behaviorally different eating disorders involving obesity.

Insomnia and eating expectancies among college students: the role of emotion dysregulation

There is limited understanding of the relation between insomnia and aspects of eating among college students though available data suggest salient clinical relationships. The present study explored a potential transdiagnostic mechanism in the relation between insomnia symptoms and eating expectancies. Participants were a racially/ethnically diverse sample of 1589 college students (80.4% females; Mage = 22.2 years, SD = 5.27) from an urban university. Primary analysis included three regression-based models of eating expectancies. Insomnia symptoms served as the predictor, and emotion dysregulation served as the indirect (mediator) variable in all models. Results indicated that insomnia symptoms yielded a significant indirect effect through emotion dysregulation on expectancies of eating to help manage negative affect, alleviate boredom, and lead to feeling out of control. Students experiencing insomnia symptoms may be at higher risk for experiencing dysregulated emotions and consequently maladaptive eating expectancies compared to good sleepers.

Adaptation and validation of the Hungarian version of the Yale Food Addiction Scale for Children

Background Childhood obesity proves to be an important public health issue, since it serves as a potential risk factor for multiple diseases. Food addiction could also serve as an important etiological factor. As childhood obesity plays a serious issue also in Hungary, we aimed to adapt and validate the Hungarian version of the Yale Food Addiction Scale for Children (H-YFAS-C). Methods A total of 191 children were assessed with the H-YFAS-C and the Eating Disorder Inventory (EDI). The following psychometric properties were analyzed: internal consistency, construct validity, convergent, and discriminant validity. Results A good construct validity was revealed by confirmatory factor analysis (RMSEA = 0.0528, CFI = 0.896, χ² value = 279.06). Question 25 proved to have no significant effect on its group and was removed from further analyses. The Kuder-Richardson 20 coefficient indicated good internal consistency (K20 = 0.82). With the use of the eight EDI subscales, a good convergent and discriminant validity could be determined. Food addiction was diagnosed in 8.9% of children. The mean symptom count was 1.7 ± 1.2 (range: 0-7). Females were more often diagnosed with food addiction than males (p = .016; OR = 3.6, 95% CI: 1.2-10.6). BMI percentiles were significantly higher in children with diagnosed food addiction (p = .003). There proved to be no correlation between age and the occurrence of food addiction. Discussion and conclusion Our results show that H-YFAS-C is a good and reliable tool for addictive-like behavior assessment.

Food Addiction and Binge Eating: Lessons Learned from Animal Models

The feeding process is required for basic life, influenced by environment cues and tightly regulated according to demands of the internal milieu by regulatory brain circuits. Although eating behaviour cannot be considered "addictive" under normal circumstances, people can become "addicted" to this behaviour, similarly to how some people are addicted to drugs. The symptoms, cravings and causes of "eating addiction" are remarkably similar to those experienced by drug addicts, and both drug-seeking behaviour as eating addiction share the same neural pathways. However, while the drug addiction process has been highly characterised, eating addiction is a nascent field. In fact, there is still a great controversy over the concept of "food addiction". This review aims to summarize the most relevant animal models of "eating addictive behaviour", emphasising binge eating disorder, that could help us to understand the neurobiological mechanisms hidden under this behaviour, and to improve the psychotherapy and pharmacological treatment in patients suffering from these pathologies.

Food addiction: Prevalence, psychopathological correlates and associations with quality of life in a large sample

OBJECTIVE

To determine the prevalence of food addiction in a large Brazilian non-clinical sample. Sociodemographic and psychopathological correlates of food addiction as well as associations with quality (QoL) domains were also investigated.

METHODS

This cross-sectional study obtained data from a Brazilian anonymous web-based research platform (N = 7639; 71.3% females). Participants provided sociodemographic data and completed the modified Yale Food Addiction Scale 2.0, PHQ-9, hypomania checklist (HCL-32), Fagerström Test for Nicotine Dependence, AUDIT, modified Skin picking-Stanford questionnaire, Minnesota impulsive disorders interview, Symptom Checklist-90-Revised inventory (SCL-90R), early trauma inventory self report-short form, and the WHO Quality of Life instrument-Abbreviated version (WHOQOL-Bref). Associations were adjusted to potential confounders through multivariable models.

RESULTS

The prevalence of food addiction was 4.32% (95%CI: 3.89-4.80%), and was more common among females. Food addiction was associated with a positive screen for a major depressive episode (OR = 4.41; 95%CI: 3.46-5.62), bipolar spectrum disorder (OR = 1.98; 95%CI: 1.43-2.75), and skin picking disorder (OR = 2.02; 95%CI: 1.31-3.09). Food addiction was also independently associated with exposure to early life psychological and sexual abuse (P = 0.008) as well as with reduced physical, psychological, social, and environment QoL (all P < 0.001).

CONCLUSIONS

Food addiction may be common in low and middle-income countries, though possibly less prevalent than in the US. Food addiction was associated with co-occurring mood disorders and skin picking disorder as well as with early life psychological and sexual abuse. Finally, food addiction was independently associated with broad reductions in QoL. Public health efforts towards the early recognition and management of food addiction are warranted.

A graduated food addiction classification approach significantly differentiates obesity among people with type 2 diabetes

This study examined a graduated severity level approach to food addiction classification against associations with World Health Organization obesity classifications (body mass index, kg/m²) among 408 people with type 2 diabetes. A survey including the Yale Food Addiction Scale and several demographic questions demonstrated four distinct Yale Food Addiction Scale symptom severity groups (in line with Diagnostic and Statistical Manual of Mental Disorders (5th ed.) severity indicators): non-food addiction, mild food addiction, moderate food addiction and severe food addiction. Analysis of variance with post hoc tests demonstrated each severity classification group was significantly different in body mass index, with each grouping being associated with increased World Health Organization obesity classifications. These findings have implications for diagnosing food addiction and implementing treatment and prevention methodologies of obesity among people with type 2 diabetes.

The prevalence of food addiction in a large sample of adolescents and its association with addictive substances

The prevalence of overweight and obesity is increasing, due to, among other factors, increased availability of highly palatable food (food high in fat, salt and/or sugar). It has been proposed that certain foods and/or eating behaviours may be addictive, to a degree comparable to substances of abuse. The Yale Food Addiction Scale (YFAS) measures 'food addiction' by translating the diagnostic criteria for substance use disorder to eating behaviour. So far, only a few studies have examined the prevalence of food addiction in children with the YFAS for children (YFAS-C). Large-scale studies, especially among adolescents, are lacking. Adolescence is of particular interest because it is a period wherein unhealthy eating behaviours or addictive tendencies are likely to develop. The current study examines the prevalence of food addiction using the YFAS-C in a large group of Dutch adolescents (N = 2653) aged 14-21 years. With Generalized Estimation Equation (GEE) analysis we tested the relationship between food addiction symptoms and smoking, cannabis use, alcohol use, and sugar intake through drinks, while controlling for gender, age, educational level and weight class. In the total sample 2.6% met the criteria for a food addiction 'diagnosis', and the average symptom count was 1.0 (SD = 1.3, range 0-7). Symptoms of food addiction were positively associated with smoking, alcohol use, cannabis use and sugar intake. We propose that future studies focus on possible genetic/(neuro)biological mechanisms involved in both food addiction and substance use and that longitudinal designs are needed to examine possible causal pathways.

Food addiction and obesity: unnecessary medicalization of hedonic overeating

The concept of addiction is loaded with connotations and is often used for its political as much as its medical utility. The scientific case for 'food addiction' as a clinical phenotype currently rests on its association with generic diagnostic criteria for substance-related disorders being applied to everyday foods and eating-related problems. This has fused the concept of obesity with addiction regardless of whether it fits the definition. The hedonic, or reward, system can account for the ingestion of foods and drugs, confirming that they share neural substrates that differentiate liking and wanting. These are normal processes that are recruited for natural homeostatic behaviours and can explain the phenomenon of hedonic overeating as a consequence of human motivation pushed to extremes by an obesogenic environment. Food addiction constitutes a medicalization of common eating behaviours, taking on the properties of a disease. The use of this medical language has implications for the way in which society views overeating and obesity.

Overlapping Neural Endophenotypes in Addiction and Obesity

Impulsivity refers to a tendency to act rapidly without full consideration of consequences. The trait is thought to result from the interaction between high arousal responses to potential rewards and poor self-control. Studies have suggested that impulsivity confers vulnerability to both addiction and obesity. However, results in this area are unclear, perhaps due to the high phenotypic complexity of addictions and obesity. Focusing on impulsivity, the aim of this review is to tackle the putative overlaps between addiction and obesity in four domains: (1) personality research, (2) neurocognitive tasks, (3) brain imaging, and (4) clinical evidence. We suggest that three impulsivity-related domains are particularly relevant for our understanding of similarities between addiction and obesity: lower self-control (high Disinhibition/low Conscientiousness), reward sensitivity (high Extraversion/Positive Emotionality), and negative affect (high Neuroticism/Negative Emotionality). Neurocognitive studies have shown that obesity and addiction are both associated with increased impulsive decision-making and attention bias in response to drug or food cues, respectively. Mirroring this, obesity and different forms of addiction seem to exhibit similar alterations in functional MRI brain activity in response to reward processing and during self-control tasks. Overall, our review provides an integrative approach to understand those facets of obesity that present similarities to addictive behaviors. In addition, we suggest that therapeutic interventions targeting inhibitory control may represent a promising approach for the prevention and/or treatment of obesity.

Psychometric properties of the Portuguese version of the Yale Food Addiction Scale

PURPOSE

Rising rates of obesity have been recently associated to the novel concept of food addiction (FA). The Yale Food Addiction Scale (YFAS) is the most widely used measure for examining FA (1) and analysis of its reliability and validity is expected to facilitate empirical research on the construct. Here, we tested the psychometric properties of a Portuguese version of the YFAS (P-YFAS), establishing its factor structure, reliability and construct validity.

METHODS

Data were obtained from 468 Portuguese individuals, 278 sampled from non-clinical populations, and 190 among obese candidates for weight-loss surgery. A battery of self-report measures of eating behavior was applied.

RESULTS

Confirmatory factor analysis verified a one-factor structure with acceptable fit, with item analysis suggesting the need to eliminate item 24 from the P-YFAS. Internal consistency (KR-20 = .82) and test-retest stability were adequate. Correlation analyses supported convergent and divergent validity of the P-YFAS, particularly in the clinical sample. Both FA symptom count and diagnosis, according to the P-YFAS, adequately discriminated between samples, with classification of FA met by 2.5 and 25.8% of the participants in the non-clinical and clinical samples, respectively.

CONCLUSIONS

These findings reinforce the use of P-YFAS in non-clinical and clinical populations. Future directions for extending YFAS validation are discussed.

Functional neuroimaging in obesity

PURPOSE OF REVIEW

This review examines recent advances in the use of functional neuroimaging to study human obesity, a field that is rapidly expanding and continues to be of paramount importance for a better understanding of the pathogenesis of this condition. With rising levels of obesity worldwide and limited therapeutic options, there is a great need for the development of new solutions that can benefit patients.

RECENT FINDINGS

Studies that utilize functional neuroimaging are beginning to shed light on the nature of behavioral and neurocognitive dysfunctions previously identified in individuals with obesity. Significant progress has occurred in the study of reward-related processes, cognition-reward interactions, mechanisms of weight loss, genetic influences and the case of obesity in children and adolescents. Research findings confirm that obesity and its related overeating behaviors are strongly associated with the brain, both at a regional level and a large-scale network level.

SUMMARY

Functional neuroimaging studies bring unprecedented levels of detail to examine the brain basis of obesity and show promise for the development of future brain-based biomarkers and interventions in this condition.

Functional neuroimaging in obesity

PURPOSE OF REVIEW

The review examines recent advances in the use of functional neuroimaging to study human obesity, a field that is rapidly expanding and continues to be of paramount importance for a better understanding of the pathogenesis of this condition. With rising levels of obesity worldwide and limited therapeutic options, there is a great need for the development of new solutions that can benefit patients.

RECENT FINDINGS

Studies that utilize functional neuroimaging are beginning to shed light on the nature of behavioral and neurocognitive dysfunctions previously identified in individuals with obesity. Significant progress has occurred in the study of reward-related processes, cognition-reward interactions, mechanisms of weight loss, genetic influences, and the case of obesity in children and adolescents. Research findings confirm that obesity and its related overeating behaviors are strongly associated with the brain, both at a regional level and a large-scale network level.

SUMMARY

Functional neuroimaging studies bring unprecedented levels of detail to examine the brain basis of obesity, and show promise for the development of future brain-based biomarkers and interventions in this condition.