One challenge in human geography is that the available data are often confidential or small samples of a population.  Spatial Microsimulation Modelling is a tool which can help to overcome these limitations and produce policy relevant results at small area level.  Obesity is a major health challenge in many countries including both Australia and New Zealand and is known to have an environmental component.  Despite this, limited information regarding the spatial distribution is available in New Zealand at present, partially due to the types of data available.  Spatial Microsimulation Modelling may help to elucidate the small area distribution of obesity and assist in improving the efficacy of interventions.