Purpose Of Dietary Reference Intakes

You may have seen the term "RDAs" vanishing from the public lexicon and getting replaced by "DRIs" in recent years. The shift represents a major change in what public health authorities think about what you should be eating on a daily basis. RDAs date back to early 20th century when they were guidelines based on what most people needed to avoid become nutrient deficient. DRIs, on the other hand, are about lowering your risk of chronic disease. Since 1997, the Institute of Medicine has been using DRIs in place of RDAs, and DRIs apply to most healthy people in all of North America. Think of DRIs as indexes of several systems that combine available scientific evidence on what you need to stay healthy. There's a DRI for how much fiber you need, how much vitamin B-12, how much fat and a host of other nutrients.

Dietary Reference Intakes

DRI is a term for a set of values that estimate how much of various nutrients healthy people need in their diets. They are categorized based on age and gender. For example, there are intake standards for children, teens, men and women and pregnant women. DRIs cover vitamins and minerals; macronutrients like carbohydrates, proteins and fats; and other nutrients including water, fiber and salt. DRIs are set by the Institute of Medicine, a nonprofit under the umbrella of the federally funded National Academy of Sciences. Healthy people can use DRI tables to determine how much of a given nutrient they need on a daily basis to lower their risk of chronic disease.

History of Nutritional Standards

The on-record role of government and health officials recommending diet and nutritional advice dates back to 19th century England when social activists advocated for the basic dietary needs to improve the plight of the poor. In the United States, under President Teddy Roosevelt, a special commission was formed to make recommendations about how to stay healthy, using food-based advice, rather than nutrient-based advice. As science progressed, advice shifted to nutrients. The goal was largely to help prevent people from becoming sick and dying from nutritional deficiencies.

From Deficiency to Prevention

By 1941, the first set of Recommended Dietary Allowances, or RDAs, made their appearance, which reigned supreme in public health diet advice until the mid-1990s. By then it was clear that additional recommendations needed to be made not only for preventing nutrient deficiencies but preventing risk of chronic diseases, like obesity and heart disease, which were becoming increasingly common. DRI took their place for this purpose. DRIs were developed in concert with public health authorities in Canada and were designed to be a set of standards used for all English-speaking people in North America.

What's in a DRI

The values that make up the DRIs are based on four factors: the Estimated Average Requirement, or EAR; the RDA; Adequate Intake, or AI; and Tolerable Upper Intake Level, or UL. EARs refer to the average amount of a nutrient needed to meet the health requirements of at least 50 percent of individuals in a given age range or gender group. The RDA is the amount needed by most of the population, 97 to 98 percent, to prevent a nutrient deficiency. AIs are used where there's not enough scientific evidence yet to establish an RDA; they're based more on judgment than on data. ULs are the highest amount you could take of a nutrient without experiencing an adverse effect. The values established for DRIs are for healthy individuals, as people with illnesses have different nutritional needs.