Jack T. Saari
Scientists at the Grand Forks Human Nutrition Research Center, its five sister nutrition research centers and numerous government and academic institutions across the country perform research that provides the public with information about healthy food choices. This includes information about how much of a given nutrient is required for optimum health and what foods are the best sources of those nutrients.
How does this scientific information make its way into the hands of the public? In a nutshell, it is evaluated and compiled by panels of scientists and made available in publications and databases. Because many of you have access to computers and the internet, today we give you directions to some of these nutritional databases and a primer for their use.
Many of you are familiar with the term RDA (Recommended Dietary Allowance). This term has now become a subset of the more general term Dietary Reference Intake (DRI), which includes, in addition to RDA, the terms Adequate Intake (AI) and Tolerable Upper Intake Level (UL). The AI is used when a definitive RDA cannot be determined from the scientific data. The UL is the maximum amount of a nutrient at which no adverse effects have been observed. The UL is useful in particular for those people, e.g. supplement takers, who might wonder "how much is too much?"
Where is DRI information found? The definitive source is a series of books, the Dietary Reference Intakes, published by the Food and Nutrition Board of the Institute of Medicine. The books may be found online at www.nap.edu. At the website type "Dietary Reference Intakes" under the phrase "Search All Titles". You may read the books on-line for free or you may order them. To obtain just the compiled tables of DRIs without the scientific explanations, go to the website www4.nas.edu/IOM/IOMHome.nsf. Click on "IOM Programs", then on "elements" or "vitamins". This information is particularly useful in that DRIs are categorized for age, sex, pregnancy and lactation.
You may know how much of a vitamin or mineral to eat, but do you know what foods provide those nutrients? The best site for that answer contains the food composition tables prepared by the Nutrient Data Laboratory of the U.S. Department of Agriculture (USDA). The website is www.nal.usda.gov/fnic/foodcomp. Click on "Release 14", then on "reports". This site will allow you to search for a food alphabetically and obtain a listing of the amount of all known nutrients in that food. Or, you may click on a specific nutrient to obtain a list of foods sorted by amount of that nutrient, thus allowing you to find the best sources for the nutrient.
Searching the DRI and food composition websites as a reference for what to eat can be a rather detailed process. While many of you are interested in that level of detail, a very good, but more general, web-based document is called Nutrition and Your Health: Dietary Guidelines for Americans, published jointly by the USDA and the Public Health Service. It is found at www.usda.gov/cnpp/DietGd.pdf. This site contains information such as how to evaluate your weight, the benefits of physical activity, use of the food pyramid to guide your food choices, sources of some important nutrients, how to read a food nutrition label, how to select healthy foods and avoid unhealthy ones and how to keep food safe to eat. The guide provides a common sense, highly readable, but relatively brief summary of the masses of food and nutrition information available today.
Key to all of these websites is their fact-based, scientifically-supported approach to healthy food choices.