Diabetes and Gastric By- Pass

Volunteers planned to undergo RYGB will be studied during two-9 days periods of identical and
controlled diet and activity, separated by a 4-10-week washout period.

Study Period #1:

This first study period is 9 days/nights long and requires you to be closely supervised at
our Clinical and Translational Research Center (CTRC). During this time you will receive the
same diet and are expected to have the same activity level you will be prescribed in the
immediate post-operative period.

Wash-out period:

During this study period you are expected to return to your usual diet and exercise level.

Study Period #2:

This last study period is also 9 days/nights long, includes the EXACT same diet you have
received during the first study period, and in addition you will undergo the planned gastric
by-pass surgery.

Procedures during the research:

Mixed Meal Challenge test will be done four times during the entire study: days 1 and 9 for
each study period. This test allows the investigators to evaluate how much insulin your body
is producing and how well this insulin is processed.

Measurement of resting energy expenditure will be done four times during the entire study.
This test tell us how much energy your body is burning up in a resting state.

Inclusion Criteria:

- volunteers that are planned to undergo RYGB(Roux-en-Y By pass) and have type 2
diabetes diagnosed within the prior 10 years.

Exclusion Criteria:

- abnormal renal function

- significant anemia

- difficult venous access

- treatment with incretin mimetics or DPP IV inhibitors in the prior 3 months

- recent change in use of any pharmacologic agent with potential effect on either
beta-cell function or insulin resistance.

- pregnancy

- non -English speakers