The protein quality of diets evaluated according to the 1968 and 1973 FAO standards

Abstract

The protein quality of 1,310 diets ingested during 24 hours families living in 18 communities in the State of S. Paulo (Brazil) was evaluated by using score levels and limiting aminoacids. The reference standards used were those proposed by the FAO in 1968 and 1973. When rated to the 1968 standard, the total number of the diets scored lower than 80, but 93.4% scored over 80 when related to the 1973 standard, and of these 33.4% were over 100. In regard to the limiting aminoacids, both standards pointed to the sulphur aminoacids as being the most frequent. In 59% of the diets, methionin was the limiter (1968 standard), and, in 49% of the diets presenting limiting aminoacids (1973 standard), the sulphur aminoacids were the limiters. Results obtained when using the 1973 FAO standard suggest that the protein quality of the studied diets was satisfactory and that a protein deficiency, if present, is a consequence of insufficient ingestion of energy food and/or protein.