We investigated the relationship between chronic kidney disease (CKD) progression and causes of CKD progression at 12, 24, and 36 months after a series of cooking classes. Patients with stage G4 CKD participated in the study, nine of which continuously participated throughout the cooking class series that were held as a form of group nutrition and dietary guidance, and eight participated either intermittently or not at all. The average speeds after 0–12 months of the estimated glomerular filtration rate decrease were significantly lower in the continuous participation group than in the non-continuous participation group. Furthermore, blood urea nitrogen (BUN), BUN-to-creatinine ratio, and inorganic phosphorus levels were remarkably lower in the continuous participation group. However, there were no significant differences in other clinical data, and no significant differences in the physician-recommended amount of energy, recommended protein intake, and frequency of personal nutrition/dietary guidance were observed between the two groups. Thus, continuous participation in the cooking class led to the practice and continuation of diet therapy. These results suggest that participation in the cooking class helped curb the progression of stage G4 CKD.