<qa>  What is the SF-36?This study tests the hypotheses that a low-fat, plant-based vegan diet improves body weight, plasma lipid concentrations, blood pressure, and, in individuals with type 2 diabetes, glycemic control, that a low-fat, plant-based diet improves health-related quality of life as measured by the Medical Outcomes Study Short Form 36-Item Health Survey SF-36, and that a low-fat, plant-based diet improves mood, as measured by the Center for Epidemiologic Studies Depression Scale-Revised CESD-R. 