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

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.

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