| Food Composition Data: A User's Perspective (1987) |
|Managing food composition data|
|Managing a nutrient data-base system: meeting users' needs and expectations|
The HVH-CWRU nutrient data-base system
The Highland View Hospital-Case Western Reserve University (HVH-CWRU) Nutrient Data Base was developed in the early 1960s to study the diets of chronically ill people who were living at home. At that time, a suitable nutrient data base was not available and, because of the large number of individuals to be studied over time, it was decided to create a food composition table using the computer . The multidisciplinary development team included a physician, a research dietitian, a biostatistician, and a systems analyst, each of whose interest was in the use of the data generated as well as the generation and processing of the data. The team approach to the continuing development and management of the system has remained until the present time. By the mid-1960s, it was recognized that there were other research efforts that would require more extensive food composition information; however, sources of funds were not found. In spite of this, the group decided to completely revise the original data base, with local support for development and research from the Division of Nutrition at Highland View Hospital and the Department of Biometry at Case Western Reserve University. Since 1978, with the dissolution of the Division of Nutrition at Highland
View Hospital, the data base has been maintained by the Departments of Biometry (at present the Department of Epidemiology and Biostatistics) and Nutrition in the School of Medicine, Case Western Reserve University.
The primary source of food composition data was, and remains, the United States Department of Agriculture (USDA) Handbook No. 8. Machine-readable forms of the data were not available during the early development years, and the data were therefore transferred by hand to computer cards. Since USDA data were not always adequate to meet the various research needs, other sources of information were used. Criteria for inclusion of data were established, the most important of which was that the data base reflect current knowledge of the nutrient composition of food. These criteria are, of course, fundamental to the validity of the entire process. For nutrients or for foods not included in Handbook No. 8, information is selected from research reports in refereed journals, directly from the food industry for brandname foods, and from calculations of recipes based on nutrient values for ingredients. Close communication is maintained with the Food Composition Group at USDA for advice and consultation regarding the reliability of all data.
The food composition table at present contains more than 3,000 food items and recipes. For each food item, there is storage space for the nutrient values per 100 grams of edible food product, shown in table 1. Information stored with each food item is illustrated in table 2. The food items are placed in one of 44 food groups and are arranged alphabetically into subgroups related to common attributes of form, preparation, processing, or nutrient content. The coding manual for the NVH-CWRU
Table 1. Nutrients included in the NVH-CWRU nutrient data base
|Animal protein||Pyridoxal B6||Cystine|
|Plant protein||Vitamin B12||Histidine|
|Total fat||Folic acid||Isoleucine|
|Animal fat||Pantothenic acid||Leucine|
|Total vitamin A||Copper||Sugars|
|Preformed vitamin A||iodine||Glucose|
|Ascorbic acid||Zinc||Reducing sugars|
Table 2. Information stored for each food item in the HVH-CWRU nutrient data base
|Food group code||2 digits|
|Food item code||4 digits|
|Food name with attributes||60 characters|
|Major source code for nutrient composition data||7 characters|
|Presence or absence of lactose and gluten||2 characters|
|Volume or household measure code||2 digits|
|Volume or household measure weight in grams||Value between 0.0001-99999|
|Alternate volume or household measure code||2 digits|
|Alternate volume or household weight in grams||Value between 0.0001-99999|
|Nutrient value for each of 71 nutrients||Value between 0.0001-99999|
|Source code for each nutrient value||1 character|
Nutrient Data Base contains a listing of all food items with identification codes, volume or household measure codes. For all food items, nutrient values may be retrieved for any one of six or seven household measures. The variety of measure codes provides considerable flexibility in expressing household or volume measures of food items and reduces professional and clerical time in preparation of data for nutrient analysis. To obtain nutrient data for an item, the following information obtained from the coding manual must be provided to the computer: (a) the food item identification number; (b) a permissible measure code; and (c) a quantity or amount of the measure.
Two versions of the nutrient data-base software are maintained. A Fortran 77 version is transportable to a large number of mainframe or mini-computers with Fortran compilers. The C version is for computers running the UNIX operating system and features simplified coded data input, file storage, and manipulation of data output.
Standard system calculations include nutrient summaries for lists of foods, menus, dietary intakes, etc., averages for up to 99 summaries, percentage of recommended dietary allowances (RDAs) for each age, sex, pregnancy or lactation category, percentage distribution of energy for total protein, total fat, total carbohydrate, animal and plant protein, animal and plant fat, refined and natural carbohydrate, polyunsaturated and saturated fatty acids. Electrolytes are expressed in weight units and in milliequivalents.
The nutrient data-base system has been made available to a large number of users for the past ten years; it has been purchased by 15 institutions and one practicing dentist. Although close communication is maintained with active owners, it has not been possible to document all of their applications. Major categories of their uses are clinical practice and research, education, market research, food-product development, and nutrient-analysis services. The institutions owning the data-base system are university academic departments, university medical centres, hospitals, food manufacturers, and a food trade association.