Dietary Intake of Chronic Kidney Disease Patients Entering the LORD Trial
Fassett, RG and Robertson, IK and Geraghty, DP and Ball, MJ and Coombes, JS, Dietary Intake of Chronic Kidney Disease Patients Entering the LORD Trial, Journal of Renal Nutrition, 17, (4) pp. 235-242. ISSN 1051-2276 (2007) [Refereed Article]
Objective: The study objective was to determine the dietary intake of patients with chronic kidney disease before
and after filtering for suspected underreporters and to investigate the impact of underreporting on the interpretation
of diet data.
Design: This was a cross-sectional study.
Setting: The study included outpatients from hospitals and clinics in Northern Tasmania, Australia.
Patients: Data from 113 patients enrolled in the Lipid Lowering and Onset of Renal Disease trial were used in this
study. Patients with serum creatinine greater than 120 mmol/L were included, and those taking lipid-lowering
medication were excluded.
Methods: Patients completed a 4-day self-report diet diary, and FoodWorks software was used to determine
their daily intake of energy, macronutrients, and specific micronutrients. Diet diaries were assessed for likely
underreporting using the Goldberg cutoff approach with a ratio of energy intake to estimated resting energy
expenditure of 1.27. Nutrient intakes were compared with current National Kidney Foundationís Kidney Disease
Outcomes Quality Initiative guidelines, World Health Organization recommendations, recommended daily allowances,
and daily values adjusted for energy intake.
Results: Demographics of the patients were as follows: male/female, 71/42; age (mean standard deviation),
60 15 years; body mass index, 28.6 6.0 kg/m2, and serum creatinine, 223.4 110.0 mmol/L. According to the
criteria, 80 patients (70.8%) were underreporting their energy intake. Underreporters were more likely to be female
and younger, and have a higher body mass index and elevated serum creatinine. In all patients, daily energy intake
(89.6 32.4 kJ/kg) was lower than recommended (125-145 kJ/kg); however, this was not the case for valid
reporters (128.3 23.7 kJ/kg). Protein intake was higher (0.9 0.3 g/kg) than recommended (0.75 g/kg) in all
patients and even higher (1.2 0.3 g/kg) in valid reporters. Mean calcium, zinc, and dietary fiber intakes were all
below recommendations in all patients, but these differences were not apparent in valid reporters.
Conclusion: Interpreting self-report diet diary data from patients with chronic kidney disease without attempting
to exclude underreporters will lead to erroneous conclusions, especially in respect to energy, protein, dietary fiber,
calcium, and zinc intakes.