The purpose of this research study is to determine how bariatric surgery affects physical activity and nutrient intake.

This research study is being done because the investigators want to determine better recommendations to provide to bariatric surgery patients.

This is a two-pronged study. The first phase is a cross-sectional study design meaning each participant will only be tested once. The investigators wish to test patients from each of the groups listed below to determine CR fitness, activity level, and nutrient intake. The investigators wish to determine if any improvements from bariatric surgery can be maintained over a 2-year period following surgery. If this is the case, our next project will be to track the patients recruited at their new visit longitudinally at all of the five time points listed below.

1. New visit with GI Nutrition
2. 1 month prior to bariatric surgery (at the time of the patient's initial visit with the surgeon (6-7 months after their new visit))
3. 6 months after bariatric surgery
4. 12 months after bariatric surgery
5. 24 months after bariatric surgery

Inclusion Criteria:

• Competent patients enrolled in the pre- or post-operative bariatric surgery program at the Center for Nutrition and Weight Management at GMC, Danville, PA.
• Ability to perform a 6 Minute Walk Test.
• Aged 18 through 70.
• Willingness to receive dietary recall phone calls and accessibility to a telephone.

Exclusion Criteria:

• Patients with severe lung disease requiring oxygen therapy.
• Pulmonary embolus or pulmonary infarction.
• Patients with cardiopulmonary disease (e.g., prior myocardial infarction, coronary artery bypass, or vascular stent).
• Unstable angina.
• Uncontrolled cardiac dysrhythmias causing symptoms or hemodynamic compromise.
• Patients with any health reason that limits walking.
• Patients with a temporary injury that limits walking.
• Patients who use a wheelchair, other assistive device for walking, or have difficulty ambulating during activities of daily living.
• Patients predetermined to be illiterate or incompetent.
• Patients who are currently pregnant or have been pregnant at any time since bariatric surgery.
• Tobacco use.
• Patients with electronic defibrillators or other embedded electronic medical devices.
• Acute systemic infection, accompanied by fever, body aches, or swollen lymph glands
• Patients who have undergone revisional bariatric surgery.

Approximately 210 Geisinger subjects will participate in this study. Participants will be volunteers from the patient population of the Center for Nutrition and Weight Management between the ages of 18 and 70 years.