Effects of Weight Loss on Foot Structure and Function in Obese Adults: A Pilot Study (WLF)

• Walking speed [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  Change in walking speed at 3 month
• Postural stability [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  Change in Fall Risk Test Score as measured by the BioDex Balance System.
• Peak plantar pressure [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  Change in dynamic peak plantar pressure during barefoot walking.
• Instruments of pain and disability [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  Change in answers on the following questionnaires: Revised Foot Function Index, the Medical Outcomes Study Short Form 36 (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index.

• Arch Height Drop [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  Change in arch height in standing compared to sitting
• Activities of Daily Living [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  Change in 50' walk time and pain, stair ascend/descend time and pain, and sit-to-stand.

Obesity is a serious medical, social, and economic problem and is becoming even greater concern, as the prevalence of overweight and obese individuals has steadily increased over the years. Excessive body weight can have a profound influence on lower extremities, including pain, degenerative disease, and compromised quality of life. However, no study to-date has examined the effects of weight change on foot structure and function in individuals over time. The purpose of this study is to determine the effects of weight reduction on foot structure and function in obese adults. Improved understanding of the relationship between body weight and foot biomechanics is needed to promote health and healthier lifestyles.

• Active Comparator: NutriSystem
  weekly behavior group weight loss education
  Intervention: Other: NutriSystem portion-controlled pre-packaged meals
• Placebo Comparator: Education
  monthly behavior group weight loss education

Inclusion Criteria:

• Men and women between the ages of 50 to 75, inclusive
• Body Mass Index is ≥ 30 kg/m2 but < 45 kg/m2 and body weight < 300 pounds
• Able to ambulate safely without the use of a walking aid (cane, crutches, or walker)
• Able to understand the information in the informed consent form and is willing and able to comply with the study-related procedures

Exclusion Criteria:

• Diabetes, stroke, end stage kidney disease requiring hemodialysis, or widespread malignant disease, gallbladder disease
• Severe peripheral vascular disease (defined as 1 < palpable pedal pulse and claudication pain in less than two blocks)
• Pregnant or nursing, as weight and hormonal changes during pregnancy may affect foot structure and function, which could confound the results of the study. Therefore, women who are pregnant or nursing will be excluded from the study.
• Not willing or able to make the required quarterly follow-up visits
• Insufficient (corrected) vision to complete the questionnaires
• Food allergies to the Nutrisystem, Inc. meal plan used in this protocol
• Participation in another formal weight loss program within last 6 months
• Uncontrolled hypertension (systolic blood pressure > 180 or diastolic blood pressure > 100 mmHg). Participants on medication treating hypertension for at least three months are allowable.
• Known atherosclerotic cardiovascular disease
• History of congestive heart failure
• History of a non-skin malignancy within the previous 5 years
• Any major active rheumatologic, pulmonary, hepatic, renal, dermatologic disease or inflammatory condition