Neural Correlates of Anti-appetite Medications: An fMRI Meta-analysis

Food craving is a health issue for a considerable proportion of the general population. Medications have been introduced to alleviate the craving or reduce the appetite via a neuropharmacological approach. However, the underlying cerebral processing of the medications was largely unknown. This study aimed to meta-analyze existing neuroimaging findings. PubMed, Web of Science, and Scopus were searched to identify relevant publications. Original studies that reported brain imaging findings using functional magnetic resonance imaging (fMRI) were initially included. The reported coordinates of brain activation available from the studies were extracted and metaanalyzed with the activation likelihood estimation (ALE) approach via the software GingerALE. The overall analysis pooling data from 24 studies showed that the right claustrum and insula were the targeted sites of altered cerebral processing of food cues by the medications. Subgroup analysis pooling data from 11 studies showed that these sites had reduced activity levels under medications compared to placebo. The location of this significant cluster partially overlapped with that attributable to affective value processing of food cues in a prior meta-analysis. No brain regions were found to have increased activity levels by medications. These neural correlates may help explain the physiological effect of food consumption by anti-appetite and anti-obesity medications.