Two sets of aggregate food consumption data, one was compiled from Food Balanced Sheet and the other was constructed from the Year Books Published by Government were used to study how food expenditure and prices influenced consumer demand for food items in Taiwan. Alternative differential demand models combining the features of the Rotterdam model and the Almost Ideal Demand System were tested. Empirical results show that Rotterdam-type responses more suitable to describe Taiwanese consumer food consumption behavior than do the other specifications. The system R^2(subscript s) obtained from these two aggregate food consumption data sets are 0.97 and 0.91. In addition, this study found that how individual food items were grouped into broad categories obviously influenced estimation results.