Band to Bypass - Metabolism Kinetics in Gastric Bypass and Banding

Gastric Banding to Bypass - Metabolism Kinetics in Gastric Bypass and Banding

The investigators want to study the changes in secretion of gastrointestinal hormones, absorption and metabolism of food and liquids before and after gastric bypass and in patients who are gastric banded but are getting conversion to a gastric bypass. All patients are with normal glucose tolerance. The investigators hypothesis that food uptake/absorption of food is faster after gastric bypass and the secretion of gastrointestinal hormones change.

Inclusion Criteria:

• Normal glucose tolerance
• Patients who are undergoing gastric bypass and patients with a gastric band to are converted to gastric bypass

Exclusion Criteria:

• Diabetes,
• Study population must undergo gastric bypass