Methods to assess the price of diets: a rapid literature review

Summary

Price and the ability to afford food are major deciding factors when we choose what to eat. To improve the Scottish diet, we need to understand how much a healthy diet costs and how this cost is calculated. This report is a rapid literature review produced for Food Standards Scotland by the University of Aberdeen. It explores the methods used to estimate the price of diets and focusses on those used in high income countries.

Summary of findings

1. Food baskets can be used to assess multiple types of diets, explore food affordability and accessibility, and monitor trends when the same items are included year on year. However, pricing products through online data collection can limit representation of retailers and certain demographics.
2. Electronic point of purchase data is more useful in showing a snapshot of current diet price and price fluctuations over time, rather than idealised or hypothetical diets.
3. The challenges of assessing the price of diets mainly come from the subjective nature of choosing food items and retailers.
4. The total sum of a food shop can mask how much individual prices of items vary.
5. Food prices cannot reflect the full cost of diets, as other factors would need to be considered, for example, costs associated with cooking food.

This report provides an overview of the current evidence base around affordability of diet, how this can be assessed, and the strengths and limitations of different methodologies.