A Randomized Trial Comparing Two Doses of Portion-Controlled Foods Within a Primary Care Weight Loss Program

We hypothesize that individuals provided with 1 meal per day of portion-controlled foods (shakes and prepared entrees) will lose as much weight as individuals provided with 2 meals per day of portion-controlled foods. The study is designed to assess whether equal weight loss can be achieved at a lower cost to the health care system (or health care payer), with patients contributing some of the cost of their own treatment.

The study has two goals. First, it will assess the efficacy of a weight loss program, using a combination of counseling by peer weight coaches and portion-controlled foods. Second, the study will test the effect of varying the "dose" of portion-controlled foods provided to patients by randomly assigning individuals to receive half or all of the food required to follow a meal replacement regimen. The primary endpoint of the study will be weight change. Secondary endpoints will include adherence to the recommended eating plan, health-related quality of life, as well as changes in waist circumference and blood pressure. The provision of "half-dose" portion-controlled foods (1 meal per day) is hypothesized to be non-inferior to provision of "full-dose" (2 meals per day). The goal of non-inferiority is important because it can demonstrate that health care payers wishing to support weight loss programs can achieve equivalent results at a lower cost. All patients have the choice regarding their use of portion-controlled foods in the study, and no patients will be asked to leave the study because of non-adherence.

Eligibility Criteria:
Inclusion Criteria:

* Patients from the University Medicine Denver, University Medicine Anschutz, and A.F. Williams clinics meeting the following criteria
* Age 18 or older
* Able to keep a food record for 3 days prior to study entry
* Able to give informed consent
* Willing to accept randomization to either treatment condition, to attend all sessions, and to complete study-related assessments
* Body mass index (BMI) ≥ 30 kg/m2 and \< 50 kg/m2
* Elevated waist circumference (≥ 88 cm for women, ≥ 102 cm for men) + any one of the following:
* Glucose intolerance (fasting glucose ≥ 100 or non-fasting glucose ≥ 140, including type 2 diabetes); individuals taking medications for diabetes qualify automatically
* Elevated blood pressure (≥130/85), including hypertension (≥140/90); individuals taking anti-hypertensive medication qualify automatically
* Hypertriglyceridemia (TG ≥ 150); individuals taking lipid-lowering medications qualify automatically
* Decreased high-density lipoprotein (HDL) cholesterol (\< 40 for men, \< 50 for women)
* Obstructive sleep apnea

Exclusion Criteria:

* Medical conditions in which significant weight loss is normally contraindicated (e.g. pregnancy, congestive heart failure requiring diuretics, poorly controlled diabetes, Stage 4 or 5 chronic kidney disease, clinically evident cirrhosis, other severe internal organ disease); exceptions may be made if a referring physician documents that it is safe and appropriate for the individual to lose weight
* Treated for cancer within the past 5 years, except for basal cell or squamous cell skin cancer; exceptions may be made with written permission from a physician
* Weight gain or loss of ≥5% of weight in the past 6 months; patients who have not been weight stable may be re-screened in 3 months
* Concurrent use of corticosteroids or second-generation antipsychotic medications (exceptions may be made for individuals using these medications who have been weight stable for 6 months)
* Psychiatric diagnoses likely to affect adherence to a research study protocol (e.g., poorly controlled schizophrenia, active substance abuse)
* Prior or planned bariatric surgery
* Participation in an organized weight loss program (e.g., Weight Watchers) at the time of enrollment