February 11/Toronto/Hospital Business Week -- According to a study from Toronto, Canada, "This review discusses recent evidence that suggests a significant underestimation of protein requirements in adult humans. Traditionally, total protein requirements for humans have been determined using nitrogen balance."

"The recent Dietary Reference Intake recommendations for mean and population-safe intakes of 0.66 and 0.8g/kg/day, respectively, of high-quality protein in adult humans are based on a meta-analysis of nitrogen balance studies using single linear regression analysis. We reanalyzed existing nitrogen balance studies using two-phase linear regression analysis and obtained mean and safe protein requirements of 0.91 and 0.99g/kg/day, respectively. The two-phase linear regression analysis is considered more appropriate for biological analysis of dose-response curves. Considering the inherent problems associated with the nitrogen balance method, we developed an alternative method, the indicator amino acid oxidation technique, to determine protein requirements The mean and population-safe requirements in adult men were determined to be 0.93 and 1.2g/kg/day and are 41 and 50%, respectively, higher than the current Dietary Reference Intakes recommendations. The indicator amino acid oxidation-based requirement values of 0.93 and 1.2g protein/kg/day and the reanalysis of existing nitrogen balance studies are significantly higher than current recommendations," wrote R. Elango and colleagues, Hospital for Sick Children.

The researchers concluded, "Therefore, there is an urgent need to reassess recommendations for protein intake in adult humans."

Elango and colleagues published the results of their research in Current Opinion in Clinical Nutrition and Metabolic Care ("Evidence that Protein Requirements Have Been Significantly Underestimated." Current Opinion in Clinical Nutrition and Metabolic Care, 2010;13(1):52-57).

For additional information, contact P.B. Pencharz, Hospital for Sick Children, Div Gastroenterol Hepatol & Nutr, Res Inst, 555 University Ave, Toronto, ON M5G 1X8, Canada.

From the February 15, 2010, Prepared Foods E-dition