Intensive cardiac rehabilitation (ICR) programs are approved by the Centers for Medicare & Medicaid Services on the basis of their expected benefits for cardiovascular disease (CVD) risk factors and health outcomes. However, the impact of outpatient ICR on diet quality, quality of life (QOL), and CVD risk factors has not been prospectively assessed. The aim of this cohort study was to test the hypothesis that patients enrolled in a Pritikin outpatient ICR program would show improved diet quality, QOL, and CVD health indexes, and that the improvements would be greater than those of patients in traditional cardiac rehabilitation (CR). Patients enrolled in ICR (n = 230) or CR (n = 62) were assessed at baseline and at visit 24. Diet quality was assessed using the Rate Your Plate questionnaire, and QOL was assessed through the Dartmouth COOP Functional Health Assessment questionnaire. Secondary end points included anthropometrics, CVD biomarkers, hemodynamics, and fitness. Patients in ICR programs displayed significant improvements at visit 24 versus baseline in Rate Your Plate and Dartmouth COOP Functional Health Assessment scores, weight, body mass index (BMI), waist circumference, fat mass, total and low-density lipoprotein cholesterol, 6-minute walk distance, and grip strength. Patients in ICR had greater improvements in diet quality (p = 0.001), weight (p = 0.001), and BMI (p <0.001) than did those in CR. In summary, this prospective study of Pritikin outpatient ICR revealed significant improvements in diet quality, QOL, adiposity, and other CVD risk factors. The improvements in diet quality, body weight, and BMI were greater than those observed with traditional CR.