Abstract Roux‐en‐Y gastric bypass (RYGB) is an effective surgical intervention for severe obesity, but the role of gastrointestinal hormones in its benefits remains unclear. We examined longitudinal pre‐to‐post‐meal gastrointestinal hormone changes and their relationships with glucose homeostasis and feeding‐related cognitive responses in women undergoing RYGB. Seventeen non‐diabetic women were evaluated pre‐RYGB (Visit 1, V1), 1‐month post‐RYGB (Visit 2, V2), and 1‐year post‐RYGB (Visit 3, V3). Plasma glucose, insulin, glucagon‐like peptide‐1 (GLP‐1), peptide YY (PYY), ghrelin, and liver‐expressed antimicrobial peptide 2 (LEAP2) were measured before and after a breakfast in all visits. Appetite ratings and feeding‐related cognitive performance were evaluated using visual analog scales, Ideal Portion Size, and Food Stroop tasks. At V3, RYGB induced weight loss (30.8%) and improved glucose homeostasis ( p = .020), accompanied by reduced hunger ( p = .042), smaller self‐reported ideal portion size ( p < .001), and improved cognitive control toward food‐cues ( p = .002). Fasting GLP‐1 and PYY levels remained stable across visits but showed enhanced post‐meal responses at V2 and V3 (GLP‐1: p < .001; PYY: p = .013). Ghrelin levels increased post‐RYGB ( p = .010) without post‐meal variation. LEAP2 concentrations remained stable. Fasting LEAP2 correlated positively with BMI at V1 ( p < .001). Fasting PYY correlated inversely with BMI at V3 ( p = .005), and its post‐meal rise inversely correlated with ideal portion size at V1 ( p = .022). GLP‐1 increments negatively correlated with ideal portion size ( p = .007) at all visits and glycemia ( p = .017) at V1. In non‐diabetic women, RYGB improves feeding‐related cognitive processes. BMI is associated with LEAP2 only pre‐surgery, and with PYY 1‐year post‐RYGB. Restoration of GLP‐1 and PYY post‐meal increments contributes to metabolic and behavioral improvements. Clinical Trial Registry: This study was registered at clinicaltrials.gov as NCT01815216. https://clinicaltrials.gov/study/NCT01815216 .
Andreoli et al. (Fri,) studied this question.