The Recommended Dietary Allowances (RDA) were established to cover the nutritional needs of all normal, healthy people living in the United States. Canada and some foreign countries each have their own RDAs. Canada has a Recommended Nutrient Intake (RNI).
The Food and Nutrition Board of the National Academy of Sciences set the values for the RDA’s based on human and animal research. They usually meet every five years to review current research on nutrients.
A Recommended Dietary Allowance is established for protein, vitamin A, D, E, K and B6, B12, C, thiamin, riboflavin, niacin, folacin, calcium, phosphorus, magnesium, iron, zinc, iodine, and selenium. The recommended amount is set to cover 98% of all normal healthy people in the United States. It does not cover the nutritional needs of people with illness or chronic disease. There is a margin of safety built into the RDAs. The average, healthy person can consume at least 67% of their RDA and still be adequately nourished.
The RDA for protein is the only nutrient containing calories. Protein, fat, carbohydrate and alcohol contribute calories. Vitamins and minerals do not contain calories. All foods except table sugar contribute nutrients to your diet. Depending on which foods you choose, the calorie content of a diet that would fulfill an individual’s RDA could range from 1600 to 2200 calories. A small adult would not necessarily get fat, nor would the large adult be malnourished. Overweight or underweight is the result of eating more calories or fewer calories respectively than a person needs. It is the food choices that a person makes in addition to exercise that determines body weight.