Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Sciences


R. Gaurth Hansen


The purpose of this study was to develop a food quality index that can provide practical information to both consumers and professional people. The Index of Food Quality (IFQ) is a simple computerized tool based on a concept of nutrient density. The IFQ was designed to organize and clarify the present body of food composition data into a form that is directly applicable to dietary problems. The IFQ provides a method of analyzing food quality based on energy needs. The nutrient contents of foods are compared to essential nutrient standards with calories as a common denominator. In developing the IFQ, the nutrient standards were usually derived from the FDA's recommended Daily Allowances (USRDA), and the value of 2300 kcal represented an average adult requirement for energy. An index number of "1" for a particular nutrient in a given food indicates that the amount of that food yielding just sufficient energy per day to maintain weight and good health will also contain exactly the recommended daily allowance of that nutrient. We developed an index number for each nutrient in each food considered in this study. A profile of index numbers was then derived for each food. One can assess whether he is meeting the RDA by calculating whether the foods he eats additively give a value of one or greater for each nutrient area. A computer program was developed that computes the nutrient indices and prints them in tabular and bar graph forms. The program is written in FORTRAN and was developed for use with a Burroughs B6700 digital computer, but is readily compatible with the IBM 360/40 system as well. The program can evaluate a single food, various foods, and combinations of foods (i.e., diets, menus, or recipes) by printing its (their) nutrient profile. The graphs reflect the nutrient quality of a food, whether it is used as a sole source of energy or as it usually contributes to the diet (serving size). Menus, recipes, and diet profiles are presented as the sum of the nutrient contents of their individual foods and are printed as composite graphs. Nutrient data is being stored on tape and on disk. As it becomes available, new data may be written out on the disk file for later intra or inter-program use, either adding to or updating old values in the library. The IFQ program is completely flexible because every parameter can be expanded and/or modified to fit the data at hand. It can be adjusted to represent guidelines for a general population or be tailored to reflect individual or special group needs. In general, the program can compare any type of data to a reference value and produce the results in a bar graph profile. Data input is minimal. The program requires only the processing of the entry cards and a single index value per food or ingredient to print a typical graph. Modification in output requires only a code change in the entry cards and/or the input of additional special nutrient values not already stored on disk. The efficiency and speed of the modern high-speed computer coupled with a program that requires a minimum of card handling makes the IFQ a useful, rapid, and inexpensive tool for nutritional analysis and planning.



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