Neural Responses to Olfactory and Gustatory Cues in Obesity:A Review of Task-Based Functional MRI Studies
10.22802/jksbtp.2025.31.2.23
- Author:
Yejin KIM
;
Youngeun SHIM
;
Sujung YOON
;
Yoonji JOO
- Publication Type:Reviews
- From:
Journal of the Korean Society of Biological Therapies in Psychiatry
2025;31(2):23-39
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objectives:Obesity is increasingly recognized not merely as excess body weight, but as a chronic condition involving metabolic dysregulation and neurobiological vulnerability. In particular, altered brain responsiveness to sensory food cues has emerged as a key mechanism underlying the development and persistence of obesity. Recent neuropsychiatric perspectives emphasize dysfunctions in reward circuits and addictive-like eating behaviors. This review aims to comprehensively synthesize task-based functional magnetic resonance imaging (fMRI) studies to examine brain responsivity in individuals with obesity or at high risk of weight gain.
Methods:We systematically reviewed 30 task-based fMRI studies using olfactory and/or gustatory cues. Studies were categorized by stimulus type, participant group, and experimental condition to compare neural responses.
Results:Across studies, key patterns included hyperactivation of reward circuits in response to high-calorie stimuli, impaired modulation of neural activity across hunger and satiety states, and exaggerated or blunted affective and motivational responses to sensory stimuli. These neural differences appeared to interact with metabolic condition, physiological state, emotional traits, and genetic predispositions, suggesting their potential utility as neurobiological markers of obesity-related eating behaviors.
Conclusions:This review underscores the relevance of sensory-driven paradigms—beyond traditional visually cued tasks—in capturing the neural basis of maladaptive eating. By elucidating the links between sensory processing and neural reward circuits, this review highlights the utility of olfactory and gustatory fMRI paradigms in refining our understanding of obesity. These insights may contribute to early identification of high-risk individuals and inform the development of neurobiologically informed, personalized intervention strategies.
