A computer simulation model is presented for studying national level issues as they affect the well being of the poor in developing countries. The model permits the user to explore the impact of various national‐level policies (such as government allocations to food production expansion, food aid to the poor, export expansion and public health and actions to change tax rates and to regulate food prices) upon a range of performance measures. The model's performance measures, computed over a time horizon of interest, include: GNP, GNP growth rate, unemployment level, nutritional status and mortality rate (by population groups), government and private indebtedness, foreign indebtedness and inflation rate. Tests of model credibility are described as are tests to explore a number of issues related to nutrition planning in the national context.