Accuracy of a Nutrient Database in Estimating the Dietary Phosphorus-to-Protein Ratio and Using a Boiling Method in Low-Phosphate Hospital Diets

Abstract

The use of the dietary phosphorus-to-protein ratio (PPR) to reduce dietary phosphorus while maintaining protein intake is valuable for nutritional management in the dialysis population, but the actual PPR values in hospital meals have not been determined. We aimed to determine the accuracy of a nutrient database for estimating the PPR in low-phosphate hospital diets compared with the accuracy of chemical analysis and produce hospital diets with low-phosphate content by boiling meat for 30 minutes before cooking. The phosphorus and protein content of 26 cooked dishes selected from the hospital menu was estimated using a food composition table (FCT) and sent for chemical analysis. Comparisons of FCT-based estimated values with measured values for every 100 g of tested foods revealed an overestimation for the PPR both in plant-based dishes (mean difference ± SD, 4.1 ± 14.6 mg/g, P = 0.06), and in meats (2.1 ± 2.3 mg/g, P = 0.06). By boiling meats, we crafted diets with PPR as low as 8 mg/g. Caution should be exercised in estimating the PPR using a FCT in hospital diets and boiling should be used to prepare hospital meals. Such diets will be promoted for dialysis patients in both inpatient and outpatient settings.

Estado nutricional e qualidade de vida de renais crônicos

“…It was noted in one study that energy intake in renal patients on hemodialysis treatment was below recommendations, becoming more severe than low protein intake. 24 It is noteworthy that the evaluation of the quality of the protein ingested is also very relevant, that is, a minimum of 50% of high biological value proteins (HBV) must be prioritized in order to ensure the intake of essential amino acids. In this study, it was observed that the amount of HBV proteins recorded was within the recommended (69%), while 31% of the patients had consumption below the recommended, corroborating the research reported.…”

“…In this study, it was observed that the amount of HBV proteins recorded was within the recommended (69%), while 31% of the patients had consumption below the recommended, corroborating the research reported. 24 It is contextualized that serum albumin had been identified as a predictor of mortality in hemodialysis (HD) patients. It is understood that the normalized protein catabolic rate (nPCR) less than 0.8 or greater than 1.4 g/kg/day was also associated with higher mortality.…”

Dietary Phosphorus and FGF23

“…One may argue that the baseline diets may have been underestimated by inaccuracies of food composition tables, as has been shown numerous times in the literature (6). However, Tsai et al (7) showed in another recent publication that food composition table estimates of phosphorus content of natural foods, free from phosphate additives, may not be marred by the same underestimation as foods with additives. In fact, their estimates of phosphorus content from food composition tables closely matched the chemically analyzed values (7).…”

“…However, Tsai et al (7) showed in another recent publication that food composition table estimates of phosphorus content of natural foods, free from phosphate additives, may not be marred by the same underestimation as foods with additives. In fact, their estimates of phosphorus content from food composition tables closely matched the chemically analyzed values (7). Thus, there is no strong reason to suspect the baseline values for phosphorus intake were underestimated drastically in this study.…”

“…So, is more phosphorus restriction better? In the context of the Tsai et al (4) study, it may well be; but perhaps, although feasible, these conditions may be aspirational in clinical settings long term, i.e., by providing nutritious meals to patients on dialysis (9), achieving adequate protein intake by minimizing the phosphorus-to-protein ratio using natural food sources free of phosphate additives, and implementing a boiling protocol to reduce phosphorus content of meats (7). Likely, long-term nutrition counseling and support from a registered dietitian would also be needed (10).…”