Effect of Soy Protein and Colorado Diet on Weight Loss and Maintenance

This is a randomized study comparing the efficacy of inducing weight loss of two treatment arms all based on the Colorado Diet. Subjects will be randomly assigned to one of two study arms and instructed to follow the Colorado Diet by participating in weekly State of Slim group classes. Subjects will be followed in the study for one year. The Colorado Diet consists of 3 phases: phase 1 (week 1-2), phase 2 (weeks 3 - 8), and phase 3 (weeks 9 - 16). The maintenance phase lasts from months 5 - 12. Body weight will be monitored at each study visit and body composition will be determined using DXA. Blood lipid and lipoprotein concentrations, health & wellness questionnaires, and fitness measures will also be assessed throughout the study.

Inclusion criteria

• BMI between 27-40
• Weight stable (have not lost or gained more than 10 pounds in the last 3 months)
• Generally healthy
• Able to exercise 70 minutes per day at moderate intensity
• Willing and able to participate in a State of Slim group class for the first 16 weeks of the study and willing to participate in 5 study visits over the 12 month study period.

Exclusion criteria

• Pregnant or trying to become pregnant.
• Diagnosis of type 1 or type 2 diabetes
• Individuals following a vegetarian only diet
• Food allergies (to soy, dairy, wheat/gluten, or peanut)
• Taking medications that could cause weight loss or weight gain or alter plasma lipids (such as steroids, tricyclic antidepressants, chemotherapy, antipsychotics, prescribed or OTC weight loss agents, statins, fibrates, niacin, etc). Oral contraceptives can be used as long as subject agrees to not change use of these during the study.
• Known renal disease
• Clinical hypothyroidism
• Current alcohol or drug abuse or dependence (Subjects who have quit smoking in the last 6 months will be excluded. Smokers whose smoking habits have been stable for the last 6 months and which remain stable during the study can be included).
• Any medical condition for which following a diet and/or 70 minutes of exercise daily would be inadvisable
• LDL cholesterol levels above 190 mg/dl or triglycerides above 400 mg/dl.