This dissertation applies the dynamic version of Quadratic Almost Ideal Demand System with the Two-Stage Budgeting Process for analyzing Japanese food consumption. The Breusch-Godfrey test and RESET2 test are employed for the different hypotheses. Furthermore, we estimate the conditional and unconditional expenditure, Marshallian and Hicksian price elasticities for food in Japan. Overall, results show that the difference between conditional and unconditional elasticities is large. It demonstrates the elasticities attained by studies that only focus on a specific commodity group might be inappropriate and should be reexamined. Key words: Dynamic QUAIDS, Two-Stage Budgeting Process, Elasticities.