The overall goal of this study is to determine whether variations in the perilipin, and several other, genes would be a useful tool for physicians who are caring for morbidly obese patients to guide therapy.

The main hypotheses to be tested is that sequence variations (polymorphisms) in the perilipin gene and several other obesity-related genes are associated with resistance to weight loss for obese individuals on energy restricted diets, potentially playing a role in the development of obesity related complications.

The PRIMARY goal of this study is to investigate the association of perilipin gene polymorphisms, with obese subjects who are "resistant" to weight loss in a defined program.

The SECONDARY goal of this study is to investigate if additional candidate obesity genes that have previously been associated with obesity or energy metabolism show association with resistance to weight loss in subjects on an energy restricted diet. Additionally, we would like to investigate if any metabolic syndrome parameters, such as dyslipidemia or abnormal fasting glucose are associated with perilipin or variations in other obesity-related genes.

Inclusion Criteria:

• Caucasian

• competent patients interested in Gastric Bypass Surgery

• patients who are eligible for Gastric Bypass Surgery based on NIH criteria:

  • Male or Female
  • 21 - 70 years old, inclusive
  • Body Mass Index (BMI) > 40 with 2 co-morbid conditions such as Sleep Apnea, Hypertension, or Type 2 Diabetes
  • BMI > 45 with no co-morbid conditions

Exclusion Criteria:

• Patients not interested in Gastric Bypass Surgery
• Patients who do not qualify for surgery based on medical contraindications
• Patients with severe psychological contraindications
• Patients not willing to be compliant with pre-post surgical recommendations
• Patients younger than 21 years of age
• Patients older than 70 years of age
• Patients who do not qualify for surgery based on insurance constraints i.e., insurance guidelines for bypass surgery
• Patients who are pregnant
• Hispanic, Black, Asian Races
• Abnormal thyroid function

Caucasian adults between the age of 21 and 70 years, inclusive, who fit the criteria for patients undergoing bariatric surgery at the Geisinger Clinic.