Reference Daily Intake

About: Reference Daily Intake is a research topic. Over the lifetime, 1564 publications have been published within this topic receiving 52794 citations.

Comparable data on food and nutrient intake and physical measurements from the 1983, 1985 and 1995 national nutrition surveys

Abstract: This report presents results from three national nutrition surveys that have been adjusted to improve data comparability. It is based on findings from a bridging study that was undertaken to assess and account for differences between the 1983 National Dietary Survey of Adults, the 1985 National Dietary Survey of Schoolchildren and the National Nutrition Survey 1995. Adjustments were made to all three sets of survey results to allow their use in dietary monitoring in Australia.

The recommended dietary allowance of protein: a misunderstood concept.

Abstract: AT PERIODIC INTERVALS THE FOOD AND NUTRITION Board of the Institute of Medicine produces a report entitled the Dietary Reference Intakes (DRI). The recent DRI report for macronutrients (energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids) was published in 2005. For each macronutrient, a series of values is published, along with a detailed review of all data used to derive those values. Those values for macronutrients are the estimated average requirement, the recommended dietary allowance (RDA), the tolerable upper intake level, and the adequate intake. Of these terms, the RDA is the most widely recognized and has the greatest influence on daily nutrition practices. The RDA is defined as follows: “The recommended dietary allowance (RDA) is an estimate of the minimum daily average dietary intake level that meets the nutrient requirements of nearly all (97 to 98 percent) healthy individuals.” In addition, the intent of the most recent DRI was to extend, where possible, beyond the concept of minimal requirement to the expression of a goal for consumption. In this case, the RDA would ideally represent an optimal intake of the nutrient, based on health outcomes such as decreased risk of heart disease. This approach was used for a number of nutrients. However, considerable confusion has resulted from the uneven application of this approach. Most notably, the RDAs for carbohydrate, fat, and protein adhere to the strict definition of the RDA (ie, the minimal amount to meet nutrient requirement, rather than an optimal level of nutrient intake). The RDA for carbohydrate was taken to be the minimal amount required to satisfy the energy requirement of the central nervous system (120 g for adults 18 years), because the central nervous system normally relies entirely on circulating glucose as an energy substitute. It was determined that there is no particular requirement for total fat intake, and therefore there is no RDA. Minimal values for required intake of linoleic acid (between 12-17 g, depending on age and sex) and n-3 polyunsaturated fats (between 1.1-1.6 g) were provided. In addition, the requirement for protein for adults older than 18 years was determined to be 0.8 g of protein per kilogram body weight per day (g/kg/d). The RDA for protein was based on the results of all available studies that estimated the minimum protein intake necessary to avoid a progressive loss of lean body mass as reflected by nitrogen balance. The Food and Nutrition Board acknowledged the conceptual limitation of relying entirely on results from nitrogen balance studies to determine the RDA, because this method does not measure any relevant physiological end point. Furthermore, the existing data were gathered almost entirely in college-aged men and a greater nitrogen intake is likely required to maintain nitrogen balance in elderly persons. Regardless of whether 0.8 g/kg/d is an appropriate value for the RDA for elderly persons as well as for 18to 50-year-old individuals, the point is that the RDA is functionally defined as the amount of protein needed to avoid a deficiency that would lead to a progressive loss of lean body mass (as reflected by negative nitrogen balance). The minimal nature of the RDAs for carbohydrate, fat, and protein is underscored by considering the sum of the energy equivalents of the corresponding RDAs in relation to the estimated energy requirements published in the same DRI document. The estimated energy requirement for a 70-kg man and a 57-kg woman older than 18 years is 3067 and 2403 kcal/d, respectively. However, when summed together, the RDAs for carbohydrate, fat, and protein for individuals of the same weight would provide approximately