In this paper, we explore the contribution of introducing a flexible form for household consumption in a macro-micro modelling context for poverty and income distribution analysis. The almost ideal demand system exhibits interesting features allowing for the introduction of inter-household heterogeneity in a rigorous fashion. In order to illustrate the contribution of the AIDS system in the macro-micro modelling context, we perform a comparative analysis with an equivalent model using a LES demand system and a CGE with representative households including an AIDS. Results show the strong contribution of using an almost ideal demand system in a microsimulation context and its value added versus a linear expenditure system to analyse poverty and income distribution changes following a policy simulation.