This book has examined the phenomenon of changes in consumption patterns in Addis Ababa city using primary data collected on 400 households by random sampling method. The study used five commodities (i.e., teff, wheat and barley, maize and sorghum, vegetables and meat and animal products). The study employed quadratic almost ideal demand system (QUAIDS) model to estimate Income elasticity and household demographic effect on household food consumption for the Addis Ababa city.