Study to Evaluate Effects of a Weight Loss Program in Different Formats on Healthy Adults

Effects of a Commercially-Available Structured Weight Loss Program Provided in Three Different Formats on Anthropometric Measures in Healthy Overweight and Obese Adults

The objective of this study was to determine changes in body weight and related outcomes achievable over a 16-week period in response to three different commercially available weight loss programs (Nutrisystem) providing pre-packed, portion controlled foods and beverages, each compared to a self-directed diet, in apparently healthy overweight and obese men and women.

A randomized, controlled, four-arm parallel study design included two screening/baseline visits (visits 1 and 2; weeks -1 and 0) and six clinic visits (visits 3, 4, 5, 6, 7, 8, and 9; weeks 1, 2, 3, 4, 8, 12, and 16). One hundred and eighty healthy overweight and obese men and women (18-70 years of age; Body Mass Index 25.00 to 44.99 kg/m2) were randomly assigned (stratified randomization by two BMI and three age categories) to one of four treatment arms: a self-directed diet, or one of three different Nutrisystem programs: 1) My Way; 2) Turbo 10; or 3) a program modeled after the Dietary Approaches to Stopping Hypertension (DASH) diet. Daily energy intake targets for each 16-week intervention were 1500 kcal/day (men) or 1200 kcal/day (women), except for the first week of the Turbo 10 intervention, which included a more aggressive 1000 kcal/day diet to start. Body weight, body circumference (chest, waist, hip, upper arm, thigh and sum of the 5), and blood pressure measurements were obtained at baseline (week 0) and at weeks 1, 2, 3, 4, 8, 12, and 16 in the morning following an overnight fast (9 to 14 hours). Total and regional fat mass and fat-free mass (lean soft tissue and bone) were quantified by dual energy x-ray absorptiometry at baseline (week 0) and at weeks 4, 8, and 16. Analyses of serum lipoprotein lipids were obtained at baseline (week 0), week 8, and week 16. Lipoprotein lipid assessments included Total Cholesterol (TC), LDL-Cholesterol, HDL-Cholesterol, non-HDL-Cholesterol (calculated as TC minus HDL-C), Triglycerides, and the Total Cholesterol/HDL-Cholesterol ratio. Plasma chemistry and whole-blood hematology analyses were conducted at screening (week -1). Questionnaires designed to assess aspects of quality of life and sleep quality were administered at baseline (week 0) and weeks 4, 8, and 16. Quality of Life assessments included the Impact of Weight on Quality of Life-Lite (IQWOL-Lite), 36-Item Short Form Health Survey (SF-36), and Leeds Sleep Evaluation Questionnaire (LSEQ).

Inclusion Criteria:

1. Subject is male or female, 18-70 years of age, inclusive.
2. Subject has a body mass index (BMI) of 25.00 to 44.99 kg/m2, inclusive, at visits 1 and 2 (weeks -1 and 0).
3. Subject has no plans to change smoking habits during the study period.
4. Subject is willing to follow study program instructions, including avoidance of all non-study-related food and beverages.
5. Subject is willing and able to comply with the visit schedule [i.e., no visit window will be allowed between visits 2 and 3 (week 0 and 1) and visits 3 and 4 (weeks 1 and 2)].
6. Subject agrees to follow the physical activity recommendations as outlined in each plan.
7. If a premenopausal female, subject has a history of regular menstrual cycles that range in length from 21 to 35 d, where applicable.
8. Judged to be in good health on the basis of medical history and screening laboratory assessments.
9. Subject understands the study procedures and signs forms providing informed consent to participate in the study and authorization for release of relevant protected health information to the study Investigators.

Exclusion Criteria:

1. Subject has an abnormal laboratory test result of clinical significance at visit 1 (week -1), at the discretion of the Investigator. One re-test will be allowed on a separate day prior to visit 2 (week 0) for subjects with abnormal laboratory test results.
2. Subject has had a weight loss or gain ≥10 lb (4.5 kg) in the 6 months prior to visit 1 (week -1).
3. Subject has used weight loss medications within 6 months of visit 1 (week -1) or weight loss supplements or programs, other than those provided, intended to alter body weight within 4 weeks of visit 1 (week -1) or during the course of the study (Appendix 1).
4. Subject has extreme dietary habits (e.g., Atkins diet, very high protein, vegetarian), in the opinion of the Investigator.
5. Subject has a known allergy, sensitivity, or intolerance to the study foods or any ingredients of the study menu provided.
6. Subject has diagnosed diabetes mellitus (type 1 or type 2) or fasting glucose ≥126 mg/dL at the screening visit (visit 1, week -1).
7. Subject has used thyroid hormones, except stable-dose replacement therapy for ≥2 months prior to visit 1 (week -1; Appendix 1).
8. Subject has used dietary supplements that, in the judgment of the Investigator, are likely to markedly affect appetite. The washout period will be 2 weeks prior to visit 1 (week -1; Appendix 1).
9. Subject has used medications or supplements that may influence carbohydrate metabolism, including but not limited to hypoglycemic medications and systemic (intravenous, intramuscular, or oral) or ≥1500 µg/d topical (inhaled, intranasal, or dermal) corticosteroids within 4 weeks of visit 1 (week -1) and throughout the study (Appendix 1).
10. Subject has a history or presence of clinically important cardiac, renal, hepatic, endocrine, pulmonary, biliary, pancreatic, or neurologic disorders.
11. Subject has an active gastrointestinal disorder such as peptic ulcer disease or malabsorption syndrome (mild lactose intolerance or gastroesophageal reflux diseases are acceptable).
12. Subject has an active infection or signs/symptoms of an infection. The baseline visit (visit 2, week 0) will be re-scheduled to allow subject to be symptom-free of any type of systemic infection for at least 5 days.
13. Subject has a history of gastrointestinal surgery for weight reducing purposes.
14. Subject has uncontrolled hypertension (systolic blood pressure ≥160 mm Hg or diastolic blood pressure ≥100 mm Hg as defined by the blood pressure measured at visit 1 (week -1). One re-test will be allowed on a separate day prior to visit 2 (week 0) for subjects whose blood pressure exceeds either of these cut points at visit 1.
15. Subject has a history or presence of cancer in the prior 2 years, except for non-melanoma skin cancer.
16. Subject is a female who is pregnant, planning to be pregnant during the study period, lactating, or is of childbearing potential and is unwilling to commit to the use of a medically approved form of contraception throughout the study period. The method of contraception must be recorded in the source document.
17. Subject is a premenopausal female using a form of hormonal contraception that does not result in a normal menstrual cycle, including a regular menses period.
18. Subject has a recent history of (within 12 months of visit 1, week -1) or strong potential for alcohol or substance abuse. Alcohol abuse defined as >14 drinks per week (1 drink = 12 oz beer, 5 oz wine, or 1½ oz distilled spirits).
19. Exposure to any non-registered drug product within 30 d prior to the screening visit (visit 1).
20. Individual has a condition the Investigator believes would interfere with his or her ability to provide informed consent, comply with the study protocol, or which might confound the interpretation of the study results or put the person at undue risk.