Neural Responses in Addictive Eating: a Systematic Review

Purpose of ReviewIt has been suggested that similar brain regions are activated to ultra-processed food as in substance addiction, giving rise to the concept of "food addiction". However, few neuroimaging studies have used specific assessment tools for food addiction, with obesity often used as a proxy, leading to considerable variability in neural activation patterns associated with food addiction. This systematic review aimed to synthesise published studies using task-related and resting-state fMRI to assess neural responses associated with food addiction, using a validated assessment tool, the Yale Food Addiction Scale (YFAS). A systematic review was conducted from 2008 to July 2022 according to the PRISMA guidelines. Studies were included if they reported YFAS food addiction outcomes in combination with task-related or resting-state fMRI outcomes. Two reviewers independently appraised studies and data were synthesised descriptively.Recent FindingsSeven task-related and four resting-state fMRI studies were included, involving 675 predominantly female participants. Brain areas involved in reward, craving, and appetitive responses were associated with YFAS-assessed food addiction in response to high-calorie processed foods in task-related fMRI studies, as well as impaired inhibition in non-food-related tasks. In the resting-state studies, altered connectivity in reward-related regions and cognitive control were commonly reported. However, activation across included studies was not consistent, with some studies reporting no relationship between food addiction scores and neural activation.SummaryThere was a lack of consistency in activation across studies which may be due to the heterogeneity of study designs. It is difficult to ascertain if there are indeed neural activation patterns that are unique to food addiction and what components of food may have addictive potential. Future studies are required with replicable study designs.