Income and Expenditure for Relatively More versus Relatively Less Nutritious Food over the Life Cycle

United States consumers have been accused of being nutritionally inefficient, having a poor quality diet, and often placing themselves at nutritional risk because of their poor choice of foods (U.S. Congress). Unfortunately, the controversy over the consumption of nutritious versus less nutritious or "junk" foods has generated heated discussion but relatively little economic research. Numerous studies have been made of the income elasticities of food consumption (Burk 1962, Hymans and Shapiro), and Engel curves derived from econometric analysis of family budgets, primarily relating expenditures on food or another consumption good or commodity group to income levels of households, ceteris paribus, abound in the literature (Burk 1968, pp. 84, 215; Aitchison and Brown; Allen; Allen and Bowley; Champernowne; Cramer; Goreux; Hassan and Johnson 1977; Houthakker 1952, 1957; Prais and Houthakker; Phlips; and Tornquist). Adrian and Daniel in their 1976 article investigated the consumption of selected food nutrients in the United States using income and the life cycle stage as variables in their analysis, but they did not identify the foods which were the sources of the nutrients. Few researchers have examined the implications of and the differences in food expenditure patterns of households at various points in their lifetimes. And, more important, no research has been done on the expenditures on and income elasticities of the specific groups of food classified as relatively more nutritious and less nutritious components of diets. The specific purposes of this analysis were to ascertain, using a general functional form, whether or not expenditures on foods classified as relatively more nutritious and less nutritious components of diets vary over the life cycle for U.S. households with different income levels, and to compare income elasticities for the various life cycle stages for all foods, relatively more and relatively less nutritious components of diets.