The primary objective is to compare inflammatory, hormonal, and metabolic changes in the very short term after various bariatric surgical procedures (Roux-en Y Gastric Bypass, Vertical Sleeve Gastrectomy, and Adjustable Gastric Banding)and other abdominal surgeries, as well as to compare these changes to diet-induced changes in the same population.

Inclusion Criteria for surgery groups:

• BMI of 30 kg/m2 or higher
• Ages 18-65
• History of impaired glucose tolerance or T2DM

Inclusion Criteria for normal weight group:

• BMI of 30 kg/m2 or lower
• Ages 18-65

Exclusion Criteria:

• Development of an intercurrent infection
• Prior gastric, duodenal, proximal jejunal surgery or pancreas resection
• Current use of thiazolidinediones
• Current use of dipeptidyl peptidase-IV inhibitors (e.g., sitagliptin) or glucagon-like peptide-1 analogs (e.g., exenatide)
• Any condition felt by the PI or co-investigators to interfere with ability to complete the study

Subjects scheduled for weight loss surgery or other abdominal surgeries will be considered for the study.