Cost of a Healthy Diet data collection protocol

Overview of the Cost of a Healthy Diet Data Collection Protocol. The Cost of a Healthy Diet (CoHD) data collection protocol was designed to provide guidance on how to collect food price data in a way that will enable researchers and practitioners to calculate the CoHD according to the Food Prices for Nutrition protocols (Food Prices for Nutrition, 2024), aligned with the global methodology used to compute the CoHD that is tracked across countries (FAOSTAT). The CoHD was established as a food price index to determine the minimum cost of meeting food-based dietary guidelines (FBDG). The data collection protocol included in the Toolbox includes guidance to inform the list of foods for which to collect prices, the sampling for food price data collection, how to collect data when food is sold in non-standardized units, timing of data collection, and how to collect prices when food prices are not listed or discounted. The data collection protocol can also be leveraged to examine how the CoHD may differ when restricting the item list to higher quality, more convenient or more sustainably produced foods, and it can be used to compare the average cost of different food groups as well as conducting other complementary food price analyses.

To assess the cost of a healthy diet. (i.e., a diet that is aligned with food-based dietary guidelines).

You should use this tool if you are interested in collecting food price data at a local level. Food price data is often collected by government ministries such as national statistical offices, or ministries of agriculture. These existing data can sometimes be leveraged for research, monitoring and evaluation. However, this information is not necessarily collected for specific local areas of interest in a project or intervention, or may not be collected for the food vendors/outlets that are accessed most by the population. In such cases, it may be preferable to collect primary data on food prices from the markets and local areas of interest.

We recommend collecting a minimum of three prices from different vendors/outlets for each of the foods included on the food lists used in the data collection. If people are accessing their foods from different places (e.g., markets, mobile vendors, local groceries), we recommend collecting food prices from the different locations.

The CoHD data collection protocol captures the external and built food environments.

The CoHD data collection protocol primarily assesses food affordability. However, it can also be used to tool assesses the dimensions of food quality, convenience, and/or sustainability if you choose to collect data that allows you to examine price differentials based on these dimensions.

An enumerator completes ascertains food prices at the vendor/outlet level.

Observing (if prices are listed) or asking vendor the price of different food items

Data collected with this tool can be used to calculate the CoHD using the country-specific food-based dietary guidelines (if they exist) or the Healthy Diet Basket (FAOSTAT, Herforth et al., 2022).

The main strengths of the data collection protocol are that it allows researchers and/or practitioners to calculate the CoHD for their specific population of interest and it can be easily compared to existing data globally.

When foods are not sold in standardized units or the prices are not listed, it can present some challenges for enumerators in terms of the time or expense taken to weigh foods and ascertaining accurate prices for food, respectively.

FAOSTAT. Cost and Affordability of a Healthy Diet. Data and methods available at: https://www.fao.org/faostat/en/#data/CAHD/

Food Prices for Nutrition. (2024) Software Tools for Calculating the Cost of a Healthy Diet, Version 7.0. Published July 2024. Tufts University, Boston (USA). Available at: https://sites.tufts.edu/foodpricesfornutrition/tools/

Herforth, A., Venkat, A., Bai, Y., Costlow, L., Holleman, C. & Masters, W.A. 2022. Methods and options to monitor the cost and affordability of a healthy diet globally. Background paper for The State of Food Security and Nutrition in the World 2022. FAO Agricultural Development Economics Working Paper 22-03. Rome, FAO. https://doi.org/10.4060/cc1169en