Inclusion Criteria:  Female patients who underwent S-RYGB, B-RYGB or E-RYGB as a primary bariatric surgery.  Exclusion Criteria:  (1) had a disease known to affect appetite, gastric emptying or gastrointestinal motility (e.g., diabetes mellitus or hyper-/hypothyroidism); (2) were unable to stop medications that affect gastric emptying and/or motility three days prior to measurements (e.g., anti-cholinergic drugs, prokinetics, theophylline, calcium blocking agents, opioids); (3) started menopause; (4) were pregnant or lactating; (5) had a drug or alcohol addiction; (6) were unable to stop smoking for 24 hours.