The Role of Reward Sensitivity and Impulsivity in Overeating and Food Addiction

The bioSocial Cognitive Theory of Eating (bSCT-e): Applying and Elaborating on a Biopsychosocial Substance Use Theory for Food Addiction

Obesity rates are increasing globally, and food addiction (FA1) may be an important contributing factor but there is a lack of understanding of the key psychological mechanisms that contribute to FA. The bioSocial Cognitive Theory (bSCT) proposes that substance use is predicted by biologically based personality traits and their influence on social cognitive mechanisms. While validated in substance use, bSCT has not been applied to a behavioural or non-substance addiction. However, the bSCT does not include a negative affective personality component, of which there is clear theoretical and empirical support as risk factors for FA. Thus, this study sought to test both the original bSCT model and an elaborated version related to eating (bSCT-e) that included direct and indirect punishment sensitivity pathways to identify the individual risk factors of FA. Data were collected from 204 university students (75.5% female; Mage = 24.82, SD = 9.17) via an online survey. Both original bSCT and bSCT-e models provided a good fit to the data, with the latter providing slightly better fit and accounting for more variance in FA. The findings suggest that individuals who are more reward driven and punishment sensitive hold exaggerated beliefs about the reinforcing and emotion regulation effects of eating, which may undermine eating control and increase risk of FA. This study provides potential new insights into the complex biopsychosocial mechanisms of FA, and points to potential intervention targets.

Association between dopamine genes, adiposity, food addiction, and eating behavior in Chilean adult

Background

A frequent consumption of high sugar/fat foods can affect dopamine signaling in the brain and cause sustained stimulation of the reward system. It has been hypothesized that a hypodopaminergic trait results in an individual overeating in order to increase brain DA. Genetic variants in this route have been connected with addiction and eating behaviors. Most studies focus on a specific SNP, and few studies have used multilocus genetic scores, which quantify genetic risk on a continuum.

Aim

To assess the relationship between multilocus genetic scores based on multiple gene variants in the dopaminergic pathway and measurements of anthropometry, eating behavior, food reinforcement, and food addiction (FA) in Chilean adults.

Methods

We recruited 221 Chilean adults for a cross-sectional study. A standard anthropometric measurement procedure was followed and eating behavior was examined using the Three Factor Eating questionnaire (TFEQ), Food Reinforcement Value Questionnaire (FRVQ), Yale Food Addiction Scale (YFAS) and 24-h diet recall. Multilocus genetic scores were calculated using TaqMan assays (rs1800497-rs1799732-rs6277-rs4680).

Results

No differences were found in the entire sample for anthropometric measurements, by MLGS. We found that participants with a score ≥ 2.0 in the MLGS showed higher food choices on the RVFQ and lower energy intake in protein, lipids, SAFA, MUFA, PUFA, dietary cholesterol, omega-3 and Omega-6 fatty acids in the 24-h recall (p < 0.05). Stratified by nutritional condition, the group with obesity had inferior scores on cognitive restriction, greater scores on uncontrolled eating, emotional eating, and responding to palatable food in the RVFQ. Also, in subjects with obesity, there was more food addiction in the group scoring "MLGS ≥2.0 or low dopamine signaling" (53%), compared to the group scored "MLGS <2.0 or high dopamine signaling" (23%) (p-value; 0.05). Emotional Eating scores correlated positively with MLGS in subjects with obesity.

Conclusion

In adults with obesity, the MLGS of the dopamine pathway, reflecting hypodopaminergic signaling, was associated with greater scores on food addiction and altered eating behavior traits.

Prefrontal-Limbic Circuitry Is Associated With Reward Sensitivity in Nonhuman Primates

BACKGROUND

Abnormal reward sensitivity is a risk factor for psychiatric disorders, including eating disorders such as overeating and binge-eating disorder, but the brain structural mechanisms that underlie it are not completely understood. Here, we sought to investigate the relationship between multimodal whole-brain structural features and reward sensitivity in nonhuman primates.

METHODS

Reward sensitivity was evaluated through behavioral economic analysis in which monkeys (adult rhesus macaques; 7 female, 5 male) responded for sweetened condensed milk (10%, 30%, 56%), Gatorade, or water using an operant procedure in which the response requirement increased incrementally across sessions (i.e., fixed ratio 1, 3, 10). Animals were divided into high (n = 6) or low (n = 6) reward sensitivity groups based on essential value for 30% milk. Multimodal magnetic resonance imaging was used to measure gray matter volume and white matter microstructure. Brain structural features were compared between groups, and their correlations with reward sensitivity for various stimuli was investigated.

RESULTS

Animals in the high sensitivity group had greater dorsolateral prefrontal cortex, centromedial amygdaloid complex, and middle cingulate cortex volumes than animals in the low sensitivity group. Furthermore, compared with monkeys in the low sensitivity group, high sensitivity monkeys had lower fractional anisotropy in the left dorsal cingulate bundle connecting the centromedial amygdaloid complex and middle cingulate cortex to the dorsolateral prefrontal cortex, and in the left superior longitudinal fasciculus 1 connecting the middle cingulate cortex to the dorsolateral prefrontal cortex.

CONCLUSIONS

These results suggest that neuroanatomical variation in prefrontal-limbic circuitry is associated with reward sensitivity. These brain structural features may serve as predictive biomarkers for vulnerability to food-based and other reward-related disorders.

Exploring the impact of impulsivity and indulgent consumption on eating patterns of Chinese consumers

There is a growing concern about unhealthy eating habits and their impact on public health, underscoring the importance of research to understand its determinants and encourage healthy food habits. Using behavioural economic insights in researching dietary habit offer advantages beyond the scope of observational studies. Therefore, this paper examines impulsivity, self-indulgence, prudence and their associations with an individual's eating habits and body mass index (BMI). Data were collected from a sample of 487 Chinese participants. Most participants (88%) had good eating habits based on the Healthy Eating Assessment score. The findings of a logistic regression analysis investigating the determinants of individual dietary behaviour based on participants' self-rating of their overall dietary habits indicate that consumers who showed temporal impulsivity for favourite food tend to have poorer habits of eating healthy foods. The results of a multiple linear regression examining the factors that influence eating habits from a composite score of the Healthy Eating Assessment indicate that the score is better with temporal impulsivity for healthy food and poor with temporal impulsivity for unhealthy food. Further, the score decreases with impulsivity measured as low self-control. The control variables, age and gender, are also significant. The findings of a linear regression analysis exploring the determinants of BMI and their association with impulsivity, self-indulgence and prudence indicate that individuals with higher impulsivity measured as low self-control are mostly in the higher BMI category. These findings are important for designing and implementing public health initiatives to promote healthier dietary habits.

Uncontrolled eating is associated with higher impulsiveness, risk taking and novelty-seeking

Previous studies suggest that trait disinhibition as measured by the Three Factor eating Questionnaire (TFEQ) is related to selected measures of impulsivity and risk taking. However, the factor validity of the original trait disinhibition measure has been questioned, and a revised scale of uncontrolled eating consequently developed. To date few studies have revisited the relationship between impulsivity and the uncontrolled and emotional eating scales of the revised TFEQ. In the present study, 283 participants (208 women) completed the revised TFEQ alongside a battery of measures of impulsivity and risk taking in an online study. The total and all subscale scores on the Barratt Impulsiveness Scale were significantly associated with scores on the uncontrolled, but not emotional or restrained, TFEQ scale. Likewise, risky behaviour indexed by the average number of pumps per trial on the Balloon Analogue Risk Task were also associated with uncontrolled, but not emotional or restrained, eating, and the same pattern of associations were also found for the novelty, but not intensity, subscales of the Arnetts Inventory of Sensation Seeking. Overall these data suggest that uncontrolled eating is related to wider personality traits of risky decision making, novelty seeking and wider cognitive impulsivity, which may in turn increase of future weight gain.

[Psychometric validation of the Yale Food Addiction Scale for Children (YFAS-C) in Spanish in a Mexican population]

Introduction

Introduction: Mexico is one of the countries with the highest prevalence of childhood obesity worldwide. The increase of addictive behaviors at an early age is a possible cause of its development. The Yale Food Addiction Scale for Children (YFAS-C) allows identifying children with food addictive behaviors. Objective: to validate the YFAS-C scale in Spanish in a population sample of Mexican children and adolescents. Material and methods: an exploratory and confirmatory factor analysis was performed. The study sample consisted of 448 children from seven to 14 years of age. The first stage involved translation into Spanish; a second stage involved the solution of questions with discrepancies; then, a reverse translation into the original language and a review by experts on the subject of eating disorders in pediatric population were performed; and in the last stage, a pilot test in order to culturally adapt the instrument and the evaluation of the psychometric properties was carried out. Results: using the principal component extraction method, four components were identified that explained 47.1 % of the sample variance. In the confirmatory factor analysis, it was found that the goodness-of-fit indices met the required values (CFI = 0.906: GFI = 0.932; AGFI = 0.915, SRMS = 0.007 and RMSEA = 0.043). Conclusions: a validated Spanish version of the YFAS-C scale was obtained for Mexican children and adolescents to assess food addiction.

Factors increasing the risk for food addiction in Ecuadorian students

Background

Food addiction (FA) is a construct that has gained interest in recent years, but its relevance in the Ecuadorian population has not yet been explored. The aims of this study were to explore the differences in the psychological profile (including FA) between university students from Ecuador and to identify the underlying structure of the relationships of the FA severity level through a mediational model.

Methods

The sample consisted of 972 university students, women and men (mean age: 20.1 years old, SD = 2.6), recruited from four Ecuadorian regions. The assessment tools included a unidimensional scale of FA, eating-related measures, emotion regulation state, impulsivity, and psychopathology state. Path analysis modeled the direct and indirect effects explaining the FA severity level.

Results

The results indicated that higher psychopathological levels were associated with FA. Similarly, no differences in FA were observed between the Ecuadorian regions. The path analysis suggested that older age, female sex, and higher difficulties in emotional regulation, impulsivity, negative mood, and anxiety trigger disordered eating; subsequently, more impaired eating behavior impacted the FA level.

Conclusion

FA is a complex clinical entity that includes multiple components related to eating disorders (EDs) and other mental health problems. The results of this study provide empirical knowledge for designing evidence-based prevention and treatment strategies.

Habitual intake of fat and sugar is associated with poorer memory and greater impulsivity in humans

The vicious cycle model of obesity suggests that repeated habitual intake of a diet high in fat and sugar (HFS) results in impairment in hippocampal function which in turn increases impulsive behaviours, making it harder to resist unhealthy diet choices. Evidence from studies with rodents consistently show switching to a HFS diet impairs performance on hippocampally-sensitive memory tasks. The limited literature in humans also suggest impaired memory and increased impulsivity related to higher habitual HFS intake. However, these changes in memory and impulsivity have been looked at independently. To investigate how these effects are inter-related, three experiments were conducted where relative HFS intake was related to measures of memory and impulsivity. In Experiment 1 (90 female participants), HFS was associated with higher scores on the Everyday Memory Questionnaire-revised (EMQ), and higher scores on the total, Attention (BISatt) and Motor (BISmot) sub-scales of the Barratt Impulsiveness Scale (BIS11). Experiment 2 (84 women and 35 men), replicated the association between HFS and EMQ, and also found HFS related to poorer performance on the hippocampally-sensitive 4 mountain (4MT) memory task. The association between HFS intake and the BISatt replicated, but there were no significant associations with other BIS11 measures or delay-discounting for monetary rewards. Experiment 3 (199 women and 87 men) replicated the associations between DFS and 4MT and EMQ, and also found an association with overall recall, but not response inhibition, from a Remembering Causes Forgetting task: HFS was also significantly associated with BIS total, BISatt and BISmot. In all three studies these associations remained when potential confounds (BMI, age, gender, hunger state, restrained and disinhibited eating) were controlled for. Mediation analysis found that the effect of HFS on memory at least part mediated the relationship between HFS and impulsivity in Experiments 1 and 3, but not 2. Overall these data provide some support for the vicious cycle model, but also suggest that trait impulsivity may be a risk factor for poor dietary choice.

Psychometric assessment of Persian translation of Yale Food Addiction Scale Version 2.0 (YFAS 2.0) in Iranian college students

BACKGROUND

Food addiction at the individual level causes physical and mental health problems, impairs individuals' social functioning, and causes dysfunction in the family system. Therefore, a tool to identify this behavioral disorder is one of the health requirements of communities. This research aimed to investigate the psychometric assessment of the Persian translation of Yale Food Addiction Scale Version 2.0 (YFAS 2.0) in Iranian college students.

METHOD

This research was cross-sectional descriptive, and 451 students were selected by convenience sampling method. Yale Food Addiction Scale Version 2.0 (YFAS 2.0), Depression, Anxiety, and Stress Scale-21 (DASS-21), and Food Craving Questionnaire-Trait, reduced (FCQ-T-r) were used to collect data.

RESULTS

The confirmatory factor analysis indicated that single-factor model provides a good fit to data (SRMR = 0.078; CFI = 0.94; NFI = 0.92; IFI = 0.94; RFI = 0.91; GFI = 0.90; RMSEA = 0.078). The YFAS's 2.0 positive correlations with three DASS-21 subscales ranged from 0.30 to 0.39, and Food Craving Questionnaire-Trait, reduced (FCQ-T-r) ranged from 0.58 to 0.72. All correlations were statistically significant, indicating acceptable convergent validity (P < 0.01).

CONCLUSION

The validity of the Persian questionnaire translation has been confirmed. Researchers and specialists can use this scale to diagnose food addiction for research or diagnostic purposes in Iranian society.

Impulsivity is longitudinally associated with healthy and unhealthy dietary patterns in individuals with overweight or obesity and metabolic syndrome within the framework of the PREDIMED-Plus trial

Background

Few studies have analyzed the associations between impulsivity and dietary patterns. Some of them have shown a cross-sectional inverse relationship between impulsivity and healthy diet scores, whereas others reported a positive association with unhealthy dietary assessments. We aimed to examine longitudinal associations of impulsivity trait with adherence to healthy and unhealthy dietary patterns in older participants at high risk of cardiovascular disease over 3 years of follow-up.

Methods

A 3-year prospective cohort analysis within the PREDIMED-Plus-Cognition study conducted in 4 PREDIMED-Plus study centers was performed. The PREDIMED-Plus study aimed to test the beneficial effect of a lifestyle intervention on the primary prevention of cardiovascular disease. The participants with overweight or obesity and metabolic syndrome included in the present study (n = 462; mean age of 65.3 years; 51.5% female) completed both the UPPS-P Impulsive Behavior Scale (range: 0–236 points) and the 143-item Food Frequency Questionnaire at baseline, 1-year and 3-years of follow-up. Ten diet scores assessing healthy and unhealthy dietary patterns were evaluated. Linear mixed models were performed adjusting by several confounders to study the longitudinal associations between impulsivity trait and adherence to dietary pattern scores over 3 years of follow-up (also assessing interactions by sex, age, and intervention group).

Results

Impulsivity were negatively associated with adherence to the Healthy Plant-Based [β = -0.92 (95%CI -1.67, -0.16)], Mediterranean [β = -0.43 (95%CI -0.79, -0.07)], Energy-Restricted Mediterranean [β = -0.76 (95%CI -1.16, -0.37)], Alternative Healthy Eating Index [β = -0.88 (95%CI -1.52, -0.23)], Portfolio [β = -0.57 (95%CI -0.91, -0.22)], and DASH [β = -0.50 (95%CI -0.79, -0.22)] diet scores over 3 years of follow-up, whereas impulsivity was positively related with adherence to the unhealthy Western diet [β = 1.59 (95%CI 0.59, 2.58)] over time. An interaction by intervention group was found, with those participants in the intervention group with high impulsivity levels having lower adherence to several healthy dietary patterns.

Conclusions

Heightened impulsivity was longitudinally associated with lower adherence to healthy dietary patterns and higher adherence to the Western diet over 3 years of follow-up. Furthermore, nutritional intervention programs should consider impulsivity as a relevant factor for the intervention success.

Trial registration

Name of registry: Effect of an energy-restricted Mediterranean diet, physical activity and behavioral intervention on the primary prevention of cardiovascular disease. Trial registration number: ISRCTN 89,898,870. Date of registration: 05/28/2014.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01335-8.

Reward Responsiveness, Learning, and Valuation Implicated in Problematic Pornography Use — a Research Domain Criteria Perspective

Purpose of Review

Problematic pornography use (PPU) describes a pattern of behavior characterized by excessive time spent using or thinking about pornography and continued use despite negative consequences. To help advance the understanding of transdiagnostic underlying psychological and neurobiological mechanisms in PPU, we aim to review existing evidence on these mechanisms focusing on positive valence systems within the transdiagnostic Research Domain Criteria (RDoC) framework.

Recent Findings

Reward anticipation processes seem to be increased in individuals with PPU symptoms when they anticipate sexual stimuli compared with other rewards. Studies further suggest that the initial neural and attentional responses to sexual rewards compared with different control stimuli are also increased in individuals with PPU symptoms, as are conditioned responses in sexual reward learning paradigms. Sexual reward valuation studies point towards an increased neural value differentiation with increasing PPU symptoms.

Summary

The current state of evidence indicates that positive valence systems are altered in persons with PPU. This framework of organizing evidence may aid in elucidating PPU development and maintenance as well as planning future studies.

The role of rash impulsivity and sensitivity to reward in soft drink consumption

Soft drink consumption has become a major public health issue. The present study aimed to examine the role of rash impulsivity and reward sensitivity in soft drink consumption using the two-factor model of impulsivity. Participants were a community sample of 229 adults (19-77 years). They completed self-report measures of impulsivity (SUPPS-P), reward sensitivity (RST-PQ) and beverage consumption (BEVQ-15). A principal component analysis was used to produce purer measures of rash impulsivity and reward sensitivity. Both rash impulsivity and reward sensitivity were positively associated with soft drink consumption, and each independently predicted soft drink consumption. Importantly, there was a significant interaction between the two, whereby rash impulsivity moderated the effect of reward sensitivity on soft drink consumption. The results support the logic of the two-factor model of impulsivity in the prediction of soft drink consumption. Further research should extend these findings to other consumption domains in both clinical and non-clinical populations.

Effectiveness of a group intervention to reduce sexual transmission risk behavior among MSM living with HIV: a non-randomized controlled pilot study

ABSTRACTWith an annual incidence of about 1.5 million new infections, HIV is an ongoing public health concern. Sexual transmission risk behavior (STRB) is a main driver of the HIV epidemic in most Western countries, particularly among specific populations such as men who have sex with men (MSM). This quasi-experimental pilot study examined the effectiveness of a ten-session group intervention, aiming to reduce STRB among a high-risk subpopulation of MSM living with HIV. Self-reported STRB, impulsivity, mental health symptoms, and functional impairment were compared between the intervention group (n = 12) and a control group (n = 16). At baseline, participants in the intervention group had higher levels of STRB, impulsivity, mental health problems, and functional impairment, compared to the control group. A significant time-by-group interaction effect revealed that after the intervention, STRB, impulsivity, and functional impairment reduced in the intervention group to levels comparable to the control group. These findings suggest that a targeted behavioral intervention might be an effective strategy to reduce persistent STRB and related factors in MSM living with HIV. Future studies should confirm these findings in larger samples, using randomized designs.

Binge eating among young adults: association with sociodemographic factors, nutritional intake, dietary n-6:n-3 ratio and impulsivity

Binge eating behaviour (BE) is the major symptom of binge eating disorder (BED). This study aimed to compare the nutritional intake in the presence or absence of BE, with a particular focus on dietary n-6:n-3 ratio, to assess the association between BE and impulsivity and the mediating effect of BMI on this association. A total of 450 university students (age 18-28 years) participated. The self-administered questionnaires were a semi-quantitative FFQ and the UPPS-P Impulsive Behavior Scale and the binge eating scale. The average BE score was 11·6 (se 7·388), and 20 % of the total participants scored above the cut-off of 17, thus presenting BE with 95 % CI of 16·3, 23·7 %. Our study revealed that greater BMI, higher total energy intake, greater negative urgency and positive urgency scores were significantly associated with BE. Participants with high value of dietary n-6:n-3 ratio were 1·335 more at risk to present a BE compared with those with a lower value of this ratio (P = 0·017). The relationship between BE score and UPPS domains score was not mediated by the BMI. This is the first study reporting a link between high dietary n-6:n-3 ratio and BE as well as the fact that BE was linked to both, negative and positive urgencies, and that the association between BE and impulsivity was not mediated by BMI. These findings can help to deal more efficiently with people suffering from BE, a symptom that can precede the development of BED.

Neuroanatomical Correlates of Binge-Eating Behavior: At the Roots of Unstoppable Eating

Binge-eating refers to episodes of uncontrolled eating accompanied by a perceived loss of control, which can be common in the general population. Given the profound negative consequences of persistent binge-eating such as weight and eating disorders, it is vital to determine what makes someone more vulnerable than others to engage in such a conduct. A total of 42 normal-weight individuals (21 with binge-eating episodes and 21 without binge-eating episodes) underwent a structural magnetic resonance imaging measurement and Voxel-based morphometry (VBM) was used to assess between-group differences in terms of gray matter volume (GMV), together with self-report impulsivity and binge-eating measures. The results showed binge-eating individuals as characterized by higher trait impulsivity and greater regional GMV in the left middle frontal gyrus: however, the GMV in this region appeared to be positively correlated only with measures of binge-eating but not with trait impulsivity measures. These findings provide novel insights on the neurobiological roots of BE in normal-weight individuals and highlight how this behavior can be associated with brain morphometric changes within prefrontal regions also in a non-clinical population. Overall, this study provides a further characterization of the neural correlates of binge-eating and novel insights into the treatment of its more severe pathological forms.

A narrative review of reward sensitivity, rash impulsivity, and food addiction in adolescents

Adolescence represents a neurodevelopmental period characterised by heightened reward drive and weaker inhibitory control that may increase vulnerability to compulsive overconsumption of highly-palatable foods and food addiction. This narrative review aimed to summarise research investigating the presence of food addiction in adolescents and establish the role that impulsivity traits (i.e., reward sensitivity and rash impulsivity), previously linked to substance and behavioural addictions, play in contributing to food addiction in this cohort. It was found that the prevalence of food addiction was typically higher in studies that recruited adolescents who were overweight/obese or from clinical populations. Overall, impulsivity was found to be more consistently associated with food addiction, while the relationships between measures of reward sensitivity and food addiction were mixed. Findings of this review suggest trait impulsivity may contribute to food addiction in adolescents, however, further longitudinal and prospective research is recommended to confirm these findings and to investigate the potential interactive effects of reward sensitivity and rash impulsivity.

How Early Stressful Life Experiences Combine With Adolescents' Conjoint Health Risk Trajectories to Influence Cardiometabolic Disease Risk in Young Adulthood

Research has primarily focused on additive (unique) associations between early stressful life experiences (specifically, socioeconomic adversity and maltreatment) and young adults' cardiometabolic disease risk without considering multiplicative (synergistic) influences. Furthermore, research has not fully considered the varying patterns of health risk trajectories (e.g., substance use, obesogenic-related behaviors, depressive symptoms) across adolescence and the transition to young adulthood that may link earlier stressful experiences and later cardiometabolic disease risk. This study examined heterogeneity in conjoint health risk trajectories from adolescence to the transition to young adulthood and their additive and multiplicative (synergistic) influences with early stressful life experiences on cardiometabolic disease risk in young adulthood using data from the National Longitudinal Study of Adolescent to Adult Health (n = 9,421; 55.6% female) over a period of 13 years. Four distinct conjoint health risk trajectories were identified considering trajectories of substance use behaviors, obesogenic-related behaviors, and depressive symptoms: (a) overall high-risk, (b) behavioral risks, (c) psycho-obesogenic risks, and (d) overall low-risk. Socioeconomic adversity and maltreatment were additively and multiplicatively associated with cardiometabolic disease risk in young adulthood. Individuals with overall high-risk conjoint trajectories averaged higher cardiometabolic disease risk in young adulthood when they were exposed to early socioeconomic adversity. Implications for personalized interventions for individuals who have experienced multiple forms of health risks are discussed.

From BIS to binge: The role of negative affect in the pathway between personality and binge eating

Recent research has highlighted the utility of using revised Reinforcement Sensitivity Theory (RST) to further understand the individual differences that influence binge eating behaviours. The current study draws on both RST and theoretical models that implicate negative affect in binge eating, with the aim of identifying indirect pathways between individual differences in RST systems and binge eating as mediated through negative affect. Undergraduate students (n = 229, M = 22.67 years of age, SD = 8.95, 76% female) completed self-report measures of revised reinforcement sensitivities, negative affect and binge eating symptoms. Bootstrapped tests of indirect effects showed that negative affect mediated the pathway between the Behavioural Inhibition System (BIS) and binge eating symptoms. Additionally, negative affect mediated the pathway between rash impulsivity and binge eating symptoms. This study supports and extends previous research by highlighting the experience of negative affect as a possible mechanism through which heightened BIS and rash impulsivity leads to binge eating.

Do ADHD-impulsivity and BMI have shared polygenic and neural correlates?

There is an extensive body of literature linking ADHD to overweight and obesity. Research indicates that impulsivity features of ADHD account for a degree of this overlap. The neural and polygenic correlates of this association have not been thoroughly examined. In participants of the IMAGEN study, we found that impulsivity symptoms and body mass index (BMI) were associated (r = 0.10, n = 874, p = 0.014 FWE corrected), as were their respective polygenic risk scores (PRS) (r = 0.17, n = 874, p = 6.5 × 10-6 FWE corrected). We then examined whether the phenotypes of impulsivity and BMI, and the PRS scores of ADHD and BMI, shared common associations with whole-brain grey matter and the Monetary Incentive Delay fMRI task, which associates with reward-related impulsivity. A sparse partial least squared analysis (sPLS) revealed a shared neural substrate that associated with both the phenotypes and PRS scores. In a last step, we conducted a bias corrected bootstrapped mediation analysis with the neural substrate score from the sPLS as the mediator. The ADHD PRS associated with impulsivity symptoms (b = 0.006, 90% CIs = 0.001, 0.019) and BMI (b = 0.009, 90% CIs = 0.001, 0.025) via the neuroimaging substrate. The BMI PRS associated with BMI (b = 0.014, 95% CIs = 0.003, 0.033) and impulsivity symptoms (b = 0.009, 90% CIs = 0.001, 0.025) via the neuroimaging substrate. A common neural substrate may (in part) underpin shared genetic liability for ADHD and BMI and the manifestation of their (observable) phenotypic association.

No association between dopaminergic polymorphisms and response to treatment of binge-eating disorder

BACKGROUND

The genetics of binge-eating disorder (BED) is an emerging topic, with dopaminergic genes being implicated in its etiology due to the role that dopamine (DA) plays in food reward sensitivity and self-regulation of eating behavior. However, no study to date has examined if DA genes influence response to behavioral treatment of BED.

OBJECTIVE

The primary objective of this study was to examine the ability of DA-associated polymorphisms to predict BED treatment response measured using binge frequency over 12 months. As secondary objectives, this study examined cross-sectional relationships between these polymorphisms and anthropometrics in women living with and without BED and obesity.

METHODS

Women aged 18-64 years old were genotyped for the DA-related SNPs DRD2/ANKK1 Taq1A (rs1800497) and COMT (rs4680), as well as the DA-related uVNTRs DAT-1 (SLC6A3) and MAO-A. A multi-locus DA composite score was formed from these 4 polymorphisms using genotypes known to have a functional impact resulting in modified DA signaling. Binge frequency (Eating Disorder Examination - Interview) and body composition (Tanita BC-418) were assessed in a pre-post analysis to examine genetic predictors of treatment response in women living with obesity and BED. Secondary data analysis was conducted on a cross-sectional comparison of three groups of women enrolled in trial group treatment for BED: women living with obesity and BED (n = 72), obesity without BED (n = 27), and normal-weight without BED (n = 45).

RESULTS

There were no significant genotype × time interactions related to anthropometrics or binge frequency for any individual DA genotypes, or to the composite score reflecting DA availability. At baseline, there were no significant between-group differences in frequencies of DA-related alleles, nor were there associations between genotypes and anthropometrics.

CONCLUSIONS

Our study found no evidence to suggest that the DRD2/ANKK1 Taq1A, COMT, MAO-A, or DAT-1 polymorphisms are associated with response to behavioral intervention for BED as measured by changes in binge frequency. Future studies should examine a greater variety of dopaminergic polymorphisms, other candidate genes that target other neurotransmitter systems, as well as examine their impact on both behavioral and pharmacological-based treatment for BED.

The Power of Food: Self-control moderates the association of hedonic hunger with overeating, snacking frequency and palatable food intake

The purpose of the study was to explore whether self-control moderates the associations between hedonic hunger and overeating frequency, snacking frequency and palatable food intake. Data from the first wave of the Swiss Food Panel 2.0 study was analyzed (N = 4774), from the German- and French-speaking part of Switzerland (52% men). Measures included hedonic hunger assessed with the Power of Food Scale (PFS), the short form Self-Control Scale, overeating frequency, snacking frequency, intake of high-fat salty snack foods, and intake of high-sugar foods assessed with a semiquantitative food frequency questionnaire. Higher scores on the PFS and lower self-control capacities were correlated with higher intakes of both high-fat salty snack foods and high-sugar foods (referred to here as palatable foods), higher overeating frequency and higher snacking frequency. Four separate moderation analyses revealed that the positive associations of hedonic hunger with overeating frequency, snacking frequency and palatable food intake were significantly attenuated by self-control. Results of the present study indicate that people who are highly sensitive to the ready availability of palatable foods but also have high levels of self-control exhibit less frequent overeating and snacking, including less frequent intake of unhealthy palatable foods, than those low in self-control. Consequently, self-control may prevent overeating and thus may serve as a protective factor that decreases the risk of becoming overweight in individuals who are highly sensitive to the food environment.

Investigating the relationship between reward sensitivity, impulsivity, and food addiction: A systematic review

OBJECTIVE

The aim of the current research was to identify the extent to which reward sensitivity and impulsivity were related to food addiction.

METHOD

Forty-five studies, published from 2009 to June 2019, investigating reward sensitivity and/or impulsivity with food addiction as measured by the Yale Food Addiction Scale were reviewed.

RESULTS

Reward sensitivity, as measured by the Sensitivity to Reward (SR) scale, was positively associated with food addiction in two studies, but failed to yield consistent results in other studies when measured with the Behavioral Inhibition/Behavioral Activation Scales. Self-report impulsivity, as measured by the Barratt Impulsiveness Scale (BIS-11), was consistently associated with food addiction, with attentional impulsivity and motor impulsivity the most consistent subscales. Similarly, food addiction was also consistently associated with Negative Urgency, Positive Urgency, and Lack of Perseverance as measured by the UPPS-P Impulsive Behavior Scale. Food addiction was inconsistently associated with disinhibition, as measured by behavioral tasks, indicating food addiction appears more aligned with self-report measures of impulsivity.

CONCLUSIONS

Research in this field is dominated by university student, overweight and obese samples. Additional research is required to further tease out these relationships.

Characterizing impulsivity and resting-state functional connectivity in normal-weight binge eaters

OBJECTIVE

Binge eating is characterized by episodes of uncontrolled eating, within discrete periods of time. Although it is usually described in obese individuals or as a symptom of Binge Eating Disorder (BED), this behavior can also occur in the normal-weight (NW) population. An interesting premise suggests that impulsivity might contribute to the onset of binge eating and the progression toward weight gain. Drawing upon this evidence, here we explored impulsivity in NW individuals reporting binge-eating episodes through a functional connectivity approach. We hypothesized that, even in the absence of an eating disorder, NW binge eaters would be characterized by connectivity pattern changes in corticostriatal regions implicated in impulsivity, similarly to the results described in BED individuals.

METHODS

A resting-state functional magnetic resonance imaging study tested 39 NW men and women, with and without binge eating (binge eaters, BE and non-BE). Brain functional connectivity was explored by means of graph theoretic centrality measures and traditional seed-based analysis; trait impulsivity was assessed with self-report questionnaires.

RESULTS

The BE group was characterized by a higher degree of trait impulsivity. Brain functional connectivity measures revealed lower degree centrality within the right middle frontal gyrus, left insula/putamen and left temporoparietal regions and a lower functional connectivity between the right middle frontal gyrus and right insula in the BE group.

DISCUSSION

The results support previous evidence on BED of altered functional connectivity and higher impulsivity at the roots of overeating behavior, but further extend this concept excluding any potential confounding effect exerted by the weight status.

Examining emotion-, personality-, and reward-related dispositional tendencies in relation to eating pathology and weight change over seven years in the Longitudinal Assessment of Bariatric Surgery (LABS) study

This study examined dispositional emotion-, personality/temperament-, and reward-related variables in relation to post-surgery eating pathology and weight-change among 107 adults who underwent Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB). As part of a prospective cohort study, annual post-surgical assessments were conducted to evaluate eating pathology, using the Eating Disorder Examination-Bariatric Surgery Version, and percent weight change from pre-surgery. Dispositional measures were administered at the 6- or 7-year assessment and included the Affect Intensity Measure, Difficulties in Emotion Regulation Scale, UPPS-P Impulsive Behavior Scale, Adult Temperament Questionnaire-Effortful Control Scale, and Sensitivity to Punishment/Sensitivity to Reward Questionnaire. Results from a series of linear mixed models revealed significant associations of emotion dysregulation, affect intensity, positive and negative urgency, effortful control, and reward sensitivity with eating pathology severity across 7 years; additionally, all but two of the subscales comprising the total scores were also significantly associated. Fewer statistically significant results were found in relation to weight change; emotion dysregulation and affect intensity (along with several subscales) were significantly associated with lower percent weight change (i.e., less weight loss), but of the reward-related and personality/temperament variables, only total effortful control emerged as significant. However, the associations of the other variables with both outcomes were consistently in the expected direction. Associations also appeared consistent across surgical procedures. Taken together, findings suggest that certain dispositional tendencies may relate to less optimal long-term outcomes following bariatric surgery and thus may be useful to assess in pre-surgical or early post-surgical evaluations to inform targeted recommendations.

Similarities and differences in revised reinforcement sensitivities across eating disorder subtypes

Reinforcement Sensitivity Theory has been used to investigate personality in the development and maintenance of disordered eating. However, the vast majority of research from this perspective has been limited by the use of measures developed to assess the original theory, rather than the significantly revised theory, potentially overlooking key personality differences in eating disorder subtypes. The current study aimed to overcome limitations when using measures based on the original theory by investigating differences and similarities in reinforcement sensitivity across eating disorder subtypes and healthy controls. The measure based on the revised theory assesses i) reward sensitivity [goal-drive persistence; reward interest, reward reactivity], ii) impulsivity, iii) behavioural inhibition, and iv) threat sensitivity. A total of 374 women from the community participated, including those with a past or present AN-R diagnosis (AN-R = 109); those with a past or present binge-type ED (Binge-type = 132); and healthy controls (HC = 133). Participants completed a questionnaire assessing personality, eating disorder symptoms, and past or present eating disorder diagnoses. Results showed that both the AN-R and Binge-type groups were higher in behavioural inhibition and threat sensitivity compared to the HC group. The Binge-type group showed higher impulsivity relative to the AN-R and HC group, and lower Goal-Drive Persistence relative to the HC group. The AN-R group showed lower Reward Interest and Reward Responsiveness relative to the HC group. This study supports and extends previous research with the findings of heightened threat and anxiety sensitivity in those with diagnosed eating disorders. Additionally, among those with a past or present eating disorder, the findings implicate impulsivity in differentiating bingeing versus restricting subtypes.