A healthful diet supplies your body with all the nutrients it needs in sufficient amounts. The question is, how much is sufficient? Promoting a balanced diet for different people is a good idea for staying healthy. However, it’s tough to define an “ideal” diet. We can’t be too specific or too general in our advice. That’s why we have Recommended Dietary Allowances (RDAs).

History of Recommended Dietary Allowances

In 1941, the Food and Nutrition Board, a subsidiary of the National Research Council and part of the National Academy of Sciences in Washington, D.C., created the Recommended Dietary Allowances (RDAs). 

This initiative aimed to address nutritional issues that could impact national defense. The committee, later renamed the Food and Nutrition Board, commenced deliberations on establishing a set of recommendations for a standard daily allowance for various nutrients. These standards were intended for nutrition guidance for the armed forces, civilians, and populations abroad requiring food relief.

Purpose of Recommended Dietary Allowances

The original purpose of RDAs was to facilitate easy meal planning for several days in advance. The “D” in RDA stands for dietary, not daily, as RDAs are designed as averages. While your nutrient intake may vary from day to day, the goal is to achieve an average over multiple days.

For instance, consider the current RDA for vitamin C, set at 75 milligrams for women and 90 milligrams for men (ages 18 and older). An 8-ounce glass of fresh orange juice contains 120 milligrams of vitamin C. Therefore, a woman could consume an 8-ounce glass of orange juice on Monday and Tuesday, skip Wednesday, and still meet the RDA over the three days. A man might need to include something else, such as a stalk of broccoli, to achieve the same result – a minor adjustment.

It’s essential to note that the RDAs offer a margin of safety for healthy individuals but are not intended for therapeutic purposes. In other words, RDA servings won’t cure a nutrient deficiency, but they serve as preventive measures against such deficiencies.

Factors affecting Recommended Dietary Allowances

Several factors influence Recommended Dietary Allowances (RDAs):

• Age (infant, adolescent, aged): Infants require more protein per kilogram of body weight than adolescents due to their faster metabolic rate.

• Sex (male, female): Adolescent girls need more iron than boys to replenish the iron lost during monthly menstruation.

• Body size (height, weight, surface area, stature): A tall and heavily built individual needs more calories than a smaller-statured person because of the larger body surface area.

• Physical state (pregnancy, lactation): Pregnant women require increased nutritional intake to meet the additional needs of the growing fetus.

• Type of work (sedentary, moderate, heavy): Sedentary workers need fewer calories than heavy workers since the latter expend more energy during work. The level of physical activity directly influences calorie requirements.

Uses of  Recommended Dietary Allowances

The Recommended Dietary Allowances (RDAs) for nutrients serve various practical purposes, including:

• Predicting Food Needs: Assisting governments in anticipating the nutritional requirements of the population.

• Food Distribution Quota: Providing a foundation for determining quotas for the distribution of food.

• Agricultural Planning: Guiding agricultural planning policies to align with nutritional needs.

• Trade Policy: Informing policies related to the export and import of food.

• Catering Establishments: Guiding the planning of nutritionally adequate diets for individuals in large catering establishments such as hospitals, hostels, and army canteens.

• Survey Evaluation: Evaluating findings from food consumption surveys conducted among different population groups.

• Adequacy of Food Supplies: Assessing the sufficiency of food supplies in meeting nutritional needs.

• Product Development: Assisting the food industry in developing and evaluating new products.

• Food Labeling Guidelines: Establishing guidelines for food labeling from a nutritional standpoint.

• Nutrition Education: Supporting the development of nutrition education programs to enhance public awareness and understanding.

Summary

Recommended Dietary Allowances (RDAs) are defined as the levels of nutrient intake that are deemed sufficient to meet the known nutritional requirements of healthy individuals. They serve as a valuable guide not only for assessing the overall nutritional adequacy of the general population but also for evaluating the adequacy of individual diets. RDAs play a crucial role in promoting balanced nutrition and supporting the health and well-being of diverse individuals.

References

1. (N.d.). Retrieved from https://agritech.tnau.ac.in/nutrition/nutri_rda_intro.html
2. Rinzler, C. A. (2021). Nutrition for dummies. Hoboken, NJ: John Wiley & Sons, inc.