Associations between Gene Expression of Appetite-Related Hormones and Disordered Eating after Bariatric Surgery: A Pilot Study

Background: Binge eating and loss-of-control (LOC) eating behaviors may persist or recur after bariatric surgery, but the underlying biological mechanisms remain unclear. This pilot study aimed to (1) examine changes in binge eating, LOC eating, appetite hormones, and appetite-related gene expression before (T1) and 3 months after bariatric surgery (T2) and (2) test whether these biological markers were associated with post-surgical binge or LOC eating. Methods: Binge eating and LOC eating were assessed using the Binge Eating Scale and the Loss of Control Over Eating Scale. Fasting blood samples were analyzed for leptin, ghrelin, and glucagon-like peptide-1 (GLP-1) levels, as well as the expression levels of the LEP, LEPR, GHRL, GLP1R, and GCG genes. Pre- to post-surgery changes were examined using Wilcoxon signed-rank tests. Generalized linear regression was used to test associations with post-surgical disordered eating. Results: Participants (total n = 21) showed significant decreases in BMI, binge eating, and LOC eating from T1 to T2. Leptin and GLP-1 levels significantly decreased at T2. No biomarkers were significantly associated with disordered eating. Conclusions: The findings highlight significant reductions in BMI, disordered eating behaviors, and leptin and GLP-1 levels following bariatric surgery. These preliminary results warrant further investigation into the biological mechanisms underlying post-surgical disordered eating in larger, more diverse cohorts with longer follow-up.