The global epidemic of obesity has surged into one of the paramount public health crises of the 21st century, yet the neurocognitive underpinnings that differentiate individuals with overweight or obesity (OW/OB) from their normal-weight (NW) counterparts remain enigmatically elusive. Recent advances in neuroimaging have begun to peel back the layers of this complexity, probing how the brain’s reward systems respond differently to various stimuli in OW/OB individuals. A cutting-edge meta-analysis spearheaded by Wang, Xiao, Hou, and colleagues, published in the International Journal of Obesity, harnesses the power of activation likelihood estimation (ALE) to unravel the neural discrepancies in processing food and monetary reward cues—a pivotal step toward decoding maladaptive eating behaviors and their neural correlates.
At the heart of this investigation lies the quest to discern whether the brain’s reward circuitry responds uniformly to all rewards or if the processing of food rewards is uniquely altered in people with OW/OB. Decades of research have implicated reward-related brain regions—such as the striatum, orbitofrontal cortex (OFC), and insula—in both hedonic eating and addictive behaviors. However, the granular distinctions in neural activations during anticipation and receipt of different reward types remained far from conclusive. This ALE meta-analysis aggregates functional MRI data from multiple studies, enabling a powerful, statistically rigorous synthesis that illuminates consistent brain activation patterns associated with each reward category.
The comprehensive analysis unveiled that although overlapping neural substrates govern reward processing broadly, distinct aberrations characterize food and monetary cue processing in individuals with OW/OB. Strikingly, the OFC and ventral striatum manifested heightened activation in response to food cues, signifying amplified hedonic valuation and craving mechanisms potentially driving overeating. Conversely, monetary rewards elicited attenuated responses in these regions, suggesting a possible deficit in general reward sensitivity or motivational salience beyond food-related stimuli. This dichotomy hints at a specialized neurocognitive adaptation or maladaptation where food acquires exaggerated incentive value amidst insensitivity to other non-food rewards.
Mechanistically, these findings resonate with incentive sensitization theories which propose that repeated exposure to palatable foods sensitizes brain reward circuits, enhancing cue-triggered craving and compulsive consumption. The meta-analysis pinpoints hyperactivity within the anterior insula and medial prefrontal cortex during food reward anticipation, regions intimately involved in interoception and executive function. Such neural signatures may underpin the heightened urge to seek food, even absent physiological hunger signals, illustrating a complex interplay between homeostatic needs and hedonic drives.
The attenuation of monetary reward responses underscores potential broader reward processing impairments in OW/OB beyond food-specific pathways. Reduced activation within reward-linked areas during monetary gain anticipation suggests a blunted sensitivity to standard reinforcers, aligning with models proposing diminished dopaminergic signaling or reward deficiency syndromes in obesity. This dual pattern—hyper-responsiveness to food cues coupled with hypo-responsiveness to monetary incentives—may foster an environment where food becomes the dominant source of reward, crowding out alternative motivational pathways.
Diving deeper, subgroup analyses highlighted that this neural divergence is not uniform across the population with OW/OB. Factors such as age, sex, comorbid psychiatric conditions, and the behavioral context modulate these brain activation patterns, underscoring the intricate heterogeneity within obesity neurobiology. Notably, in individuals with concurrent depressive symptoms, the hypoactivity to monetary rewards intensified, suggesting overlapping neural mechanisms between obesity and affective disorders in reward circuit dysfunction.
The methodological rigor of using ALE meta-analysis here cannot be overstated. By integrating coordinates from numerous fMRI studies while controlling for spatial uncertainty, ALE facilitates the extraction of convergence patterns that transcend individual sample idiosyncrasies or scanner differences. This approach lends robustness to the observed neurofunctional discrepancies and enables identification of core brain regions that consistently differentiate food versus monetary reward processing in OW/OB. Such meta-analytic syntheses represent a crucial advance over fragmented results typical of isolated neuroimaging investigations.
Beyond theoretical insights, these findings carry profound clinical implications. Therapeutic strategies for obesity might require refinement by targeting the specific neural circuits over-activated by food cues rather than employing generalized reward system interventions. Neuromodulation approaches like transcranial magnetic stimulation (TMS) or neurofeedback aimed at normalizing OFC or insular hyperactivity could prove promising. Concurrently, enhancing sensitivity to non-food rewards through behavioral activation therapies might rebalance motivational hierarchies and reduce pathological reliance on food for reward.
Moreover, this meta-analysis opens avenues for precision medicine in obesity treatment by identifying neurobiological markers that predict individuals’ responsiveness to different interventions. For instance, persons exhibiting pronounced food cue hyper-responsiveness but intact non-food reward processing might benefit more from cognitive interventions aimed at cue exposure and craving management, whereas those with global reward hypoactivity could respond better to pharmacological augmentation of dopaminergic signaling.
The juxtaposition of food versus monetary reward processing abnormalities also provides a framework for reinterpreting epidemiological observations linking obesity with disorders characterized by dysfunctional reward handling—such as addiction, depression, and ADHD. The shared neural substrates and overlapping patterns suggest convergent neurocognitive vulnerabilities, advocating for interdisciplinary frameworks combining psychiatry, neurology, and nutrition science to holistically tackle obesity.
Nevertheless, the meta-analysis also highlights vital gaps that necessitate further inquiry. Most included studies predominantly enrolled middle-aged adults of certain ethnic backgrounds, limiting generalizability. Longitudinal data remain scarce, impeding causality inference regarding whether neural abnormalities precede obesity or result from chronic metabolic changes. Additionally, disentangling the contributions of peripheral factors, such as inflammation and hormonal alterations, on central reward processing remains a pressing challenge.
In sum, this landmark investigation charts a nuanced neurofunctional landscape wherein individuals with overweight or obesity exhibit divergent brain responses to food and monetary rewards. It paints a compelling portrait of enhanced food cue reactivity interwoven with a blunted general reward system—a recipe potentially fueling compulsive overeating and resistance to non-food-based reinforcers. By unpacking these neurocognitive subtleties, the study sets the stage for innovative, targeted interventions that transcend calorie counting and embrace the intricate neural choreography of reward, craving, and behavior in the battle against obesity.
As obesity continues its relentless march, the elucidation of distinct neural reward processing abnormalities offers a beacon of hope. Future research synergizing neuroimaging, behavioral paradigms, and pharmacogenomics will be pivotal in refining individualized treatments. Harnessing such insights could transform obesity management from a one-size-fits-all paradigm to a sophisticated endeavor tailored to each person’s unique brain signature—unlocking the door to more effective, enduring solutions in the war on excess weight.
Subject of Research: Neurofunctional abnormalities in reward processing associated with overweight and obesity.
Article Title: Differentiating the abnormalities of food and monetary reward cue processing associated with overweight/obesity: an ALE meta-analysis.
Article References:
Wang, N., Xiao, M., Hou, X. et al. Differentiating the abnormalities of food and monetary reward cue processing associated with overweight/obesity: an ALE meta-analysis. Int J Obes (2026). https://doi.org/10.1038/s41366-026-02026-1
Image Credits: AI Generated
DOI: 03 February 2026
Tags: activation likelihood estimation in neurosciencebrain responses to food cuesfood vs money reward processinghedonic eating and brain activitymeta-analysis of fMRI studiesneural correlates of maladaptive eatingneurocognitive differences in obesityneuroimaging and obesity researchpublic health crisis of obesityreward systems in overweight individualsstriatum and orbitofrontal cortex rolesunderstanding obesity through neurobiology
