UC Irvine

Objectives: Studies suggest that maintenance hemodialysis (MHD) patients report dietary energy intakes (EIs) that are lower than what is actually ingested. Data supporting this conclusion have several important limitations. The present study introduces a novel approach of assessing underreporting of EI in MHD patients. Design: Comparisons of EI of free-living MHD patients determined from food records to their measured energy needs. Setting: Metabolic research ward. Subjects: Thirteen clinically stable MHD patients with unchanging weights whose EI was assessed by dietitian interview-assisted 3-day food records. Intervention: EI was compared with (1) patients' resting energy expenditure (REE), measured by indirect calorimetry, and estimated total energy expenditure (TEE) and (2) patients' dietary energy requirements (DER) measured while patients underwent nitrogen balance studies and consumed a constant energy diet in a research ward for a mean duration of 89.5days. DER was calculated as the actual EI during the research study corrected for changes in body fat and lean body mass measured by Dual X-Ray Absorptiometry. Main Outcome Measure: Underreporting of EI was determined by an EI:REE ratio <1.27 and an EI:TEE ratio or EI:DEE ratio <1.0. Results: Seven of the 13 MHD patients studied were male. Patient's ages were 47.7±standard deviation 9.7years; body mass index averaged 25.4±2.8kg/m2, and dialysis vintage was 53.3±37.1months. The EI:REE ratio (1.03±0.23) was significantly less than the cutoff value for underreporting of 1.27 (P=.001); 12 of 13 patients had EI:REE ratios <1.27. The mean EI:TEE ratio was significantly less than the cutoff value of 1.0 (0.73±0.17, P<.0001), and 12 MHD patients had EI:TEE ratios <1.0. The EI:DER ratio was also <1.0 (0.83±0.25, P=.012), and 10 MHD had EI:DER ratios <1.0. Conclusions: Dietitian interview-assisted diet records by MHD patients substantially underestimate the patient's dietary EI.