Modelling

Project aims and design

The aim of the project is to estimate the effects of nutrition policy options on population health in New Zealand.

First, the different nutrition policy scenarios to be evaluated will be specified in consultation with the Programme Advisory Group and other stakeholders. The key output will be change in HALYs (Health Adjusted Life Years).  Next, the input parameters will be created for modelling. Finally, the health effects of the interventions or policy scenarios will be determined using modelling techniques.

This research is now underway and will use data generated from the other DIET projects.

Project Progress

We are modelling the effect of a number of different interventions that fall under the DIET programme:

  • An intervention that reduces portion sizes of single serve sugar sweetened beverages(SSB) that are available for purchase. Two main scenarios are being modelled: a percentage reduction of serving sizes and a cap where single serve SSBs can’t be sold over e.g. 250mls. We model the effects of this intervention through changes in consumption onto health outcomes.
  • We are modelling the likely effect of the current levels of reformulation seen in the New Zealand food supply as a result of the introduction of the Health Star Ratings scheme. We are looking at changes in energy density and salt content of packaged foods that now carry the Health Star Ratings and apply these changes in nutrient content to the current New Zealand diets.
  • We are taking output data (i.e., multiple observations of prices and purchased amounts) from the Price Exam project and are using these as inputs to econometric models (using Bayesian methods) to estimate accurate PE values. These PE values will be used in our models to estimate the health gains of various food and beverage taxes and subsidies.
  • We have a dietetics Masters student working on “Determining the dietary patterns associated with meeting the WHO 10% and 5% of total energy free sugars guideline in New Zealand adults: Secondary analysis of the 2008/09 Adult Nutrition Survey data.”. The difference between those meeting and those not meeting the guidelines will be modelled to estimate the associated health benefit.

Lead Researcher

This project will be led by Professor Tony Blakely at The University of Otago Wellington.