Weight loss achieved by dieting induces multiple changes. These changes include a decrease
in metabolic rate (the rate in which the body burns its calories), an increase in appetite
and other physiological and hormonal changes that may be the cause of failure in dieting.
Many of these parameters that have never been evaluated when weight is lost after gastric
bypass surgery will be tested in this study.
While gastric bypass surgery (GBS) is known to be highly effective in achieving significant
weight loss, it is also associated with other biologic changes that occur in the body when
weight is lost. In this study, subjects undergoing gastric bypass surgery will be followed
throughout the weight loss period. They will undergo four detailed medical evaluations to
assess changes in several biological systems that occur in the body when weight is lost.
The initial assessment will be performed before the surgery (testing period 1). After
surgery is completed, subjects will attend clinic visits at the Rockefeller University
outpatient clinic. During these visits, weight and leptin levels will be monitored. Two
additional assessments will be performed during weight loss, when subjects lose 10% and 20%
of their initial weight (testing periods 2 and 3 respectively). A final evaluation will be
performed after weight is stabilized, about 18 months after the surgery is completed
(testing period 4). Each testing period will be performed over a 2 week period in an
inpatient setting at the Rockefeller University Hospital. During testing periods subjects
will undergo a series of metabolic, behavioral, hormonal, immune and molecular tests to
evaluate changes that occur in the body after weight loss. Subjects will receive monetary
compensation for participating in the study.
- 18 - 65 years old
- Subjects approved for gastric bypass surgery
- Subjects not approved for gastric bypass surgery