Evaluation of amino acid patterns in recipes for kidney disease patients

To examine first-limiting amino acids in EAA patterns of a low-protein diet from card-style printed recipes on the market in Japan. In addition, this research explored practical knowledge about which combination of foods could cause an imbalance, if any, of amino acids, and seek to further improve diets for patients with kidney disease.

Thirty-nine card-style printed recipes for patients with diabetic nephropathy or chronic renal disease or those already on dialysis were chosen for this study. These recipes are available at major book stores in Japan. From each recipe, the first-limiting amino acid, if any, and corresponding amino acid score were investigated and identified. To determine them, the reference amino acid scoring pattern in Report of a Joint FAO/WHO Ad Hoc Expert Committee, 1973, was used as a reference.

Among the 39 cards (recipes) examined, we found threonine to be the first-limiting amino acid in 59% of those samples, followed by valine in 8%, methionine + cystine in 3%, lysine in 3%, and leucine in 3%. In the remaining 26%, we did not find any limiting amino acids. Amino acid scores ranged from > or = 100 (26%) to 90-99 (54%), 80-89 (18%), and 70-79 (3%).

In 26% of the samples, no deficits in regard to amino acid patterns were found in our analysis of these recipes. Valine, which is an index of malnutrition, was found to be among the first-limiting amino acids. However, because amino acid scores of less than 79 represented only 3% of all recipes chosen, EAAs in protein-controlled diets might not necessarily be deficient.

The majority of the tested sample recipes were not balanced in EAA pattern, especially for threonine as the first-limiting amino acid of a meal. To prevent malnutrition in chronic renal disease, especially for those following low-protein diets, well-balanced meals on a daily basis as well as adequate energy intake are considered to be necessary.