Dietary requirement is the amount of proteins or amino acids, that must be supplied in the diet in order to satisfy the metabolic demand and achieve nitrogen balance. So, the recommended dietary allowance is given to ensure that the diet supplies adequate protein. The protein recommendations differ according to the requirements of an individual, at different stages of life, physical activity, medical conditions, body composition, goal etc.
The method of assessing the protein requirement of an individual can be in terms of loss of nitrogen through feces, urine and skin. This loss of nitrogen is assessed by maintaining an individual on a protein-free diet and estimating the fecal and urinary excretion of nitrogen. There is formula for calculating that, but we won’t be discussing that here.
DRI (Dietary Reference Intake) values as per the 2005 report, by the Food & Nutrition Board, Institute of Medicine, National Academy of Sciences, US, established a set of reference values for dietary energy, carbohydrate, fibre, fat, fatty acids, cholesterol, protein, and amino acids to expand and replace previously published Recommended Dietary Allowances (RDAs) and Recommended Nutrient Intakes (RNIs) for the United States and Canada, respectively.
Acc. to the report, Dietary Reference Intakes (DRIs) comprise a set of reference values for specific nutrients, each category of which has special uses. The development of DRIs expands on the periodic reports called Recommended Dietary Allowances, published from 1941 to 1989 by the National Academy of Sciences, and Recommended Nutrient Intakes, published by the Canadian government.
The reference values, collectively called the Dietary Reference Intakes (DRIs), include the Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), Adequate Intake (AI), and Tolerable Upper Intake Level (UL). Establishment of these reference values requires that a criterion of nutritional adequacy be carefully chosen for each nutrient, and that the population for whom these values apply be carefully defined.
A requirement is defined as the lowest continuing intake level of a nutrient that, for a specific indicator of adequacy, will maintain a defined level of nutrition in an individual.
Recommended Dietary Allowance (RDA): the average daily dietary nutrient intake level sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group. The RDA is intended to be used as a goal for daily intake by individuals as this value estimates an intake level that has a high probability of meeting the requirement of a randomly chosen individual.
Adequate Intake (AI): the recommended average daily intake level based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate—used when an RDA cannot be determined.
Tolerable Upper Intake Level (UL): the highest average daily nutrient intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects may increase.
Estimated Average Requirement (EAR): the average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group.
In the case of energy, an Estimated Energy Requirement (EER) is provided. The EER is the average dietary energy intake that is predicted to maintain energy balance in a healthy adult of a defined age, gender, weight, height, and level of physical activity consistent with good health. In children and pregnant and lactating women, the EER is taken to include the needs associated with the deposition of tissues or the secretion of milk at rates consistent with good health.
There is much less certainty about an AI value than about an RDA value. Because AIs depend on a greater degree of judgment than is applied in estimating an EAR and subsequently an RDA, an AI may deviate significantly from, and may be numerically higher than, an RDA. For this reason, AIs must be used with greater care than is the case for RDAs. Also, an RDA is usually calculated from an EAR by using a formula that takes into account the expected variation in the requirement for the nutrient.
Tolerable Upper Intake Limit (UL): is the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals in the specified life stage group. As intake increases above the UL, there is the potential for an increased risk of adverse effects. The UL is not intended to be a recommended level of intake, as there is no established benefit for healthy individuals if they consume a nutrient in amounts exceeding the recommended intake (the RDA or AI).
The need for setting ULs has arisen as a result of the increased fortification of foods with nutrients and the use of dietary supplements by more people and in larger doses. The UL applies to chronic daily use and is usually based on the total intake of a nutrient from food, water, and supplements if adverse effects have been associated with total intake. For some nutrients, data may not be sufficient for developing a UL. This indicates the need for caution in consuming amounts greater than the recommended intake; it does not mean that high intake poses no potential risk of adverse effects.
Acceptable Macronutrient Distribution Ranges (AMDR): is defined as a range of intakes for a particular energy source that is associated with reduced risk of chronic diseases while providing adequate intakes of essential nutrients. The AMDR is expressed as a percentage of total energy intake because its requirement, is not independent of other energy fuel sources or of the total energy requirement of the individual. Each must be expressed in terms relative to each other.
Because much of this evidence is based on clinical endpoints (e.g., coronary heart disease, diabetes, cancer, and obesity), which point to trends rather than distinct endpoints, and because there may be factors other than diet that may contribute to chronic disease, it is not possible to determine a defined level of intake at which chronic disease may be pre- vented or may develop. Therefore, an AMDR is not considered to be a Dietary Reference Intake (DRI) that provides a defined intake level. An AMDR is provided to give guidance in dietary planning by taking into account the trends related to decreased risk of disease identified in epidemiological and clinical studies.
A key feature of each AMDR is that it has a lower and upper boundary, some determined mainly by the lowest or highest value judged to have an expected impact on health. If an individual consumes below or above this range, there is a potential for increasing the risk of chronic diseases shown to affect long-term health, as well as increasing the risk of insufficient intakes of essential nutrients.
[Each type of Dietary Reference Intake (DRI) refers to the average daily nutrient intake of individuals over time. The amount consumed may vary substantially from day-to-day without ill effects in most cases. More- over, unless otherwise stated, all values given for Estimated Average Requirements (EARs), Recommended Dietary Allowances (RDAs), Adequate Intakes (AIs), or Acceptable Macronutrient Distribution Ranges (AMDRs) represent the quantity of the nutrient or food component to be supplied by foods from diets similar to those consumed in Canada and the United States. Healthy subgroups of the population often have different requirements, so special attention has been given to the differences due to gender and age, and often separate reference intakes are estimated for specified subgroups.
For some nutrients (e.g., trace elements), a higher intake may be needed for healthy people if the degree of absorption of the nutrient is unusually low on a chronic basis (e.g., because of very high fibre intake). If the primary source of a nutrient is a supplement, a higher or lower percentage may be absorbed and so a smaller or greater intake may be required, or an adverse effect may be demonstrated at a lower level of intake.
The DRIs apply to the apparently healthy population, and while the RDAs and AIs are levels of intake recommended for individuals, meeting these levels would not necessarily be sufficient for individuals who are already malnourished. People with diseases that result in malabsorption syndrome or who are undergoing treatment such as dialysis may have increased requirements for some nutrients. Special guidance should be provided for those with greatly increased nutrient needs or for those with decreased needs such as energy due to disability or decreased mobility. Although the RDA or AI may serve as the basis for such guidance, qualified medical and nutrition personnel should make necessary adaptations for specific situations.]
World Health Organization, Food and Agriculture Organization, and International Atomic Energy Agency (WHO/FAO/IAEA) Expert Consultation on Trace Elements in Human Nutrition and Health. That publication uses the term basal requirement to indicate the level of intake needed to prevent pathologically relevant and clinically detectable signs of a dietary inadequacy. The term normative requirement indicates the level of intake sufficient to maintain a desirable body store, or reserve. In developing an RDA, emphasis is placed instead on the reasons underlying the choice of the criterion of nutritional adequacy used to establish the requirement. It is not designated as basal or normative.
Infants Aged 7-12 Months: 1.0-1.2 g/kg/d
During the second 6 months of life, solid foods become a more important part of the diet of infants and add a significant amount of protein to the diet.
Children Aged 1-13 Years:
1–3 years – 1.05 g/kg/d
4–8 years – 0.95 g/kg/d
9–13 years – 0.95 g/kg/d
Ages 14-18 Years:
RDA for Boys 14–18 years – 0. 85 g/kg/d
RDA for Girls 14–18 years – 0. 85 g/kg/d
Ages 19-50 Years:
RDA for Men
19–30 years: 0.80 g/kg/d
31–50 years: 0.80 g/kg/d
RDA for Women
19–30 years: 0.80 g/kg/d
31–50 years: 0.80 g/kg/d
Ages 51 Years & Older:
RDA for Men
51–70 years: 0.80 g/kg/d
> 70 years: 0.80 g/kg/d
RDA for Women
51–70 years: 0.80 g/kg/d
> 70 years: 0.80 g/kg/d
RDA for Pregnancy
All age groups: 1.1 g/kg/d
RDA for Lactation
All age groups: 1.3 g/kg/d
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