becoming an increasingly larger proportion of the population; lack of sufficient emphasis on the range of appropriate macronutrient intakes; lack of relevance to chronic disease and the concomitant need to address dietary fat, fiber, and some vitamins; lack of information that addresses nutrient needs over the life cycle; little consideration of nutrient interactions; and lack of consideration for varying activity levels. Moreover, since the RDAs build in a margin of safety, some individuals were concerned that actual requirements are overestimated, making it difficult to determine at what levels of intake a population is truly at risk.
Several speakers commented that perhaps the RDAs are attempting to fulfill too many purposes. They argued that professionals and the public may be better served by having several levels of dietary allowances established to address different needs and purposes. One suggestion was that more than one set of guidelines be developed, similar to the approach taken by the United Kingdom (U.K.) (COMA, 1991). The U.K. approach includes developing three values for each nutrient: a low value estimating a deficiency state, a value representative of the population's average requirement, and a third value analogous to the current RDA and approximately two standard deviations above the average requirement. Others additionally recommended setting an upper safe level of intake that would be established where undesirable health effects are likely to occur in the population as a whole.
Several requested that consideration be given to developing a separate set of RDAs for use in food labeling, while cautioning that frequent changes in the RDAs would pose financial hardships to industry. One individual urged that international harmonization be considered if the FNB were to develop an RDA for food labeling purposes.
Throughout the testimony, many individuals emphasized the need for additional documentation to explain the derivation of the numbers and to facilitate their appropriate applications. Additional documentation would describe the state of knowledge concerning the levels of nutrients and food components needed for health promotion and disease prevention, to provide guidance to professionals who are using the RDAs for a variety of applications, and to identify gaps in knowledge so research priorities can be established. A suggestion was made to merge dietary guidelines with the RDAs to promote one consistent message to the public and to provide this information for the public's use in a less scientific and more accessible publication than the traditional RDA text.