Alterations in Reward Network Functional Connectivity are Associated with Increased Food Addiction in Obese Individuals
Soumya Ravichandran1, Ravi R. Bhatt1,6, Bilal Pandit1, Vadim Osadchiy1,2, Anita Alaverdyan1, Priten Vora1, Jean Stains1-3, Bruce Naliboff1-4, Emeran A. Mayer1-5, Arpana Gupta1-4
1G. Oppenheimer Center for Neurobiology of Stress and Resilience, Ingestive Behavior and Obesity Program; 2David Geffen School of Medicine; 3Vatche and Tamar Manoukian Division of Digestive Diseases; 4UCLA Microbiome Center; 5Ahmanson-Lovelace Brain Mapping Center at UCLA; 6Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California
Background: Functional neuroimaging studies in obesity have identified alterations in the connectivity within the reward network leading to decreased homeostatic control of ingestive behavior. However, the neural mechanisms underlying sex differences in the prevalence of food addiction in obesity is unknown. Aim: To identify functional connectivity alterations associated with: (1) Food addiction, (2) Sex- differences in food addiction, (3) Ingestive behaviors. Methods: 150 participants (females: N= 103, males: N=47; food addiction: N=40, no food addiction: N=110) with high BMI ≥ 25 kg/m2 underwent functional resting state MRIs. Participants were administered the Yale Food Addiction Scale (YFAS), to determine food addiction (YFAS Symptom Count ≥3), and completed ingestive behavior questionnaires. Connectivity differences were analyzed using a general linear model in the CONN Toolbox and images were segmented using the Schaefer 400, Harvard-Oxford Subcortical, and Ascending Arousal Network atlases. Significant connectivities and clinical variables were correlated. Statistical significance was corrected for multiple comparisons at q<.05. Results: (1) Individuals with food addiction had greater connectivity between brainstem regions and the orbital frontal gyrus compared to individuals with no food addiction. (2) Females with food addiction had greater connectivity in the salience and emotional regulation networks and lowered connectivity between the default mode network and central executive network compared to males with food addiction. (3) Increased connectivity between regions of the reward network was positively associated with scores on the General Food Cravings Questionnaire-Trait, indicative of greater food cravings in individuals with food addiction. Conclusions: Individuals with food addiction showed greater connectivity between regions of the reward network suggesting dysregulation of the dopaminergic pathway. Additionally, greater connectivity in the locus coeruleus could indicate that the maladaptive food behaviors displayed by individuals with food addiction serve as a coping mechanism in response to pathological anxiety and stress. Sex differences in functional connectivity suggest that females with food addiction engage more in emotional overeating and less cognitive control and homeostatic processing compared to males. These mechanistic pathways may have clinical implications for understanding the sex-dependent variability in response to diet interventions.
Table 1. Summary of all Group Comparisons in Network Connectivity (Food Addiction and Sex)
| Network | Food Addiction vs. No Food Addiction | Females with Food Addiction vs. Males with Food Addiction | Females with Food Addiction vs. Females with No Food Addiction | Males with Food Addiction vs. Males with No Food Addiction |
| Brainstem | Food Addiction ↑ | Females with Food Addiction ↑ | Males with Food Addiction ↑↓ | |
| Emotional Regulation | Food Addiction ↓ | Females with Food Addiction ↑ | Females with Food Addiction ↓ | |
| Salience | Females with Food Addiction ↑ | Males with Food Addiction ↑ | ||
| Sensorimotor | Food Addiction ↓ | Females with Food Addiction ↑ | Females with Food Addiction ↓ | Males with Food Addiction ↓ |
| Central Autonomic | Females with Food Addiction ↑ | |||
| Central Executive | Females with Food Addiction ↓ | Females with Food Addiction ↑ | ||
| Default Mode | Females with Food Addiction ↓ | Males with Food Addiction ↑ |
Abbreviations: ↑, Greater connectivity; ↓, Lower Connectivity
Acknowledgements/Funding Support: This research was supported by grants from the National Institutes of Health including K23 DK106528 (AG), R01 DK048351 (EAM), P50 DK064539 (EAM), and pilot funds were provided for brain scanning by the Ahmanson-Lovelace Brain Mapping Center.
Breakout Room: Ravichandran, Soumya
View Poster: https://uclacns.org/symposium2021/18-Ravichandran-Soumya.pdf