Selected physiological changes following RYGB and VSG that are implicated in weight loss and improvements in postprandial glucose metabolism. Adapted from19
| RYGB | VSG | |
| Glucagon-like peptide-1 | ↑↑ | ↑ |
| Peptide YY 3–36 | ↑↑ | ↑ |
| Ghrelin | ↓ | ↓↓ |
| Glucose-dependent insulinotropic polypeptide | ↓ | – |
| Oxyntomodulin | ↑ | – |
| Neurotensin | ↑ | – |
| Bile acids | ↑ | ↑ |
| Gut microbiota composition | ‘Lean’ phenotype | – |
| Vagal afferent signalling | ↑ | ↑ |
RYGB, Roux-en-Y gastric bypass; VSG, vertical sleeve gastrectomy.