The potential threshold for dietary energy intake (DEI) that might prevent protein-energy wasting (PEW) in chronic kidney disease (CKD) is uncertain. The subjects were non-dialysis CKD patients aged ≥ 14 years who were hospitalized from September 2019 to July 2022. PEW was measured by subjective global assessment (SGA). DEI and dietary protein intake (DPI) were obtained by 3-days diet recalls. Patients were divided into adequate DEI group and inadequate DEI group according to DEI ≥ 30 or < 30 kcal/kg/d. Logistic regression analysis and restricted cubic spline (RCS) were used in this study. We enrolled 409 patients, with 53.8% had hypertension and 18.6% had diabetes. The DEI and DPI was 27.63 ± 5.79 kcal/kg/day and 1.00 (0.90,1.20) g/kg/day, respectively. 69.2% of participants in inadequate DEI group. Malnutrition occurred in 18.6% of patients. Comparing to patients in adequate DEI group, those in inadequate DEI group had significantly lower total lymphocyte count (TLC), serum cholesterol (Chol) and low-density cholesterol (LDL), and a higher prevalence of PEW. For every 1kcal/kg/day increase in DEI, the incidence of PEW was reduced by 12.0% [odds ratio (OR): 0.880, 95% confidence interval (CI): 0.830 to 0.933, P < 0.001]. There was a nonlinear curve relationship between DEI and PEW (overall P < 0.001), and DEI ≥ 27.6 kcal/kg/d may have a preventive effect on PEW in CKD. Low DPI was also significantly associated with malnutrition, but not when DEI was adequate. Decreased energy intake may be a more important factor of PEW in CKD than protein intake.