This study uses nonparametric techniques to analyze the stability of demand for 19 major food categories among various demographic groups in the United States. Households are divided into population groups by income, the head's age, and the spouse's education level. The data used are from the 1980-1990 Dairy portion of the Bureau of Labor Statistics annual Consumer Expenditures Surveys. The programming model developed by Sakong and Hayes is used to test for and measure taste changes. Substantial differences in preference trends between population groups are found for many of the food commodities.