Final answer:
The statement that RDAs were the first reference standards for determining nutrient needs of populations is incorrect. RDAs are part of the broader DRIs and are based on the EAR to meet the needs of the majority of healthy individuals.
Step-by-step explanation:
The Recommended Dietary Allowances (RDAs) are guidelines used to determine the optimal intake levels of essential nutrients. The statement claiming that the RDAs "were the first reference standards for determining nutrient needs of populations" does not accurately describe the RDA's. In fact, the RDAs are included within the broader Dietary Reference Intakes (DRIs), designed to cover the nutrient needs of 97-98% of healthy individuals. The RDA is calculated using the Estimated Average Requirement (EAR), which represents the nutrient intake level estimated to meet the needs of 50% of the population. An EAR must be established through research before an RDA can be defined.
The RDA is particularly useful for professionals in assessing dietary needs and helps inform guidance on the intake of various nutrients for different populations, including hospitalized patients, but it was not the first system used for such purposes. Over time, these guidelines have been refined and updated to reflect new scientific knowledge and changes in dietary patterns and health objectives.