The Cost of the Diet

What is Cost of the Diet?

The Cost of the Diet is an innovative method and software developed by Save the Children UK to estimate the amount and combination of locally available foods that are needed to provide a typical family or individual with a diet that meets their average needs for energy and their recommended intakes of protein, fat and micronutrients. The method was developed as a response to research undertaken by Save the Children which demonstrated that the impact of traditional nutrition education programmes has been limited because of the economic constraints facing many households in low-income countries.

The tool aims to answer the following questions:

1. What is the minimum cost of foods that meet the nutrient needs of a typical household?
2. Can a nutritious diet be achieved by people using locally available foods?
3. Is this diet affordable?
4. If not, what could be done?

CotD Process

Cost of Diet Process

A Cost of the Diet assessment follows a logical process from identifying the food security and nutrition problem, collecting and analysing data, through to report writing, including recommendations and conclusions.The figure at the side gives an overview of the tasks and information required a Cost of the Diet assessment. The Cost of the Diet Practitioner’s Guide explains each of these steps in more detail.

The timeframe for a Cost of the Diet assessment will depend upon the length of data collection. Use the following timeframe as a rough guide:

  • Week 1:      Background literature review
  • Week 2:      Recruit and train staff, identify markets, write a food list
  • Week 3:      Collect market data, conduct interviews and FGDs 
  • Week 4:      Enter, clean and analyse data
  • Wks 5/6:     Write report

CotD Staff Requirements:

Data Collection

Cost of the Diet assessments are designed to be undertaken in an area with similar livelihoods and market access. Livelihood zones, as defined using the process outlined in the Household Economy Analysis (HEA Analysis), are the most common way to define an assessment area for a CotD assessment, though administrative units have also been used.

Before data collection begins, a detailed list of all foods (local, imported, grown and wild) available at any time during the year is compiled. This list is used as the basis for the market survey and interview questionnaire.

A market survey is conducted in 6-8 markets, representative of the assessment area or livelihood zone, where the poorest households purchase their food from. Price and weight data of all foods in the market is collected for each season. Market traders are asked questions about annual trends in prices, seasonality and changes in the demand and supply of commodities. These results are converted into a price per 100g which is entered into the software.

Focus group discussions (FGD) are conducted in 4 villages in order to create a nutritious diet that considers typical dietary habits. Each FGD should consist of 8 participants; 2 from each wealth group identified by the HEA. All participants should be those responsible for preparing food for the household. The interview questionnaire is based upon the food list generated before and during the market survey and aims to determine how often foods are consumed when they are in season. Questions are based on observations from the market data, comments from traders and responses to the questionnaire. Information is collected on key staples, household food production, ‘normal’ consumption patterns, cultural taboos and wild foods consumed.

Applied constraints are intended to reflect typical dietary patterns rather than economic constraints, as Cost of the Diet is a tool used to illustrate a diet that could be achieved if economic limits were removed.

Cost of the Diet Software

Cost of the Diet software uses the collected data to generate hypothetical diets using a combination of foods that will enable a family to meet their energy and nutrient requirements, as recommended by the World Health Organisation and the Food and Agriculture Organisation, at the lowest possible cost.

Limitations, or constraints, may be used to reflect typical household food consumption patterns. For example, specifying that a particular food is eaten three times a day, every day. In this way, the software can identify a diet that is more realistic in terms of the frequency with which foods are eaten.

The software can estimate the cost of four hypothetical diets:

1. Energy-only diet: Meets specified needs for energy only
2. Macronutrient diet:  Meets specified needs for energy, fat and protein only
3. Nutritious diet: Meets specified needs for all nutrients at lowest cost
4. Food habits, nutritious diet: Meets specified needs for all nutrients at lowest cost using typically consumed local foods

The software produces the following outputs for each of the four diets:

 For an individual or household:

  • Average daily cost of the diet
  • Average monthly cost of the diet
  • Daily cost of the diet by season
  • Percentage of nutrient specifications met by the diets, by season 
  • Annual cost of the diet
  • Annual diet summary 
  • Affordability of diets by wealth group, if HEA data available (or other income source)
  • Cost of the food groups by week (food habits diet only)
  • Seasonal cost fluctuations (food habits diet only)

The software produces the following outputs for each of the four diets:

For each food selected by the software:

  • Total daily weight (g) 
  • Total weekly weight (g) 
  • Edible daily weight (g)
  • Edible weekly weight (g) 
  • Cost of the edible daily weight
  • Cost of the edible weekly amount 
  • Daily number of servings
  • Weekly number of servings 
  • Daily amount of each nutrient provided by the edible portion
  • Weekly quantity of each nutrient provided by the edible portion 
  • Percentage (%) of each nutrient target provided a day by the edible portion 
  • Percentage (%) of each nutrient target provided a week by the edible portion 

Cost of the Diet software can:

  • Estimate minimum cost of a locally specified diet for a range of household types
  • Take into account seasonal variation in prices
  • Identify the least expensive sources of energy and all nutrients
  • Identify nutrients for which it may be hard to meet requirements
  • Identify the foods that contribute the most to the cost of the diet
  • Estimate the cost of the diet for typical families (between 5-10 members), aligned with income data generated from HEA, to estimate the affordability
  • Estimate the impact on the diet or its cost of potential interventions that might help households meet their needs for energy and nutrients

‘What if?’ models may be generated in Cost of the Dietfor specific individuals or households as a whole, to determine the potential effect of:

  • New or existing nutrition interventions
  • New or existing food security interventions
  • New or existing social protection interventions
  • Changing the nutrient specifications
  • Sudden shocks
  • Current infant and young child feeding practices

… on the cost, quality, composition and affordability of a nutritious diet.

Uses of Cost of the Diet Data

The Cost of the Diet (CotD) is predominantly used as a a programme design and advocacy tool to inform discussions on food, dietary diversity, nutrition and livelihoods.

As the software can calculate the cost of a nutritious diet for up to 6 seasons, the results can offer a unique perspective on seasonal changes in the price and availability of foods, identifying periods where households may be vulnerable to high food prices which affect their ability to afford a nutritious diet. This offers an insight for nutrition and health programme managers to assess when nutrition and food security interventions may have the greatest impact.

CotD foods can help to understand and identify:

  • Nutrients hardest to obtain from locally available foods
  • Foods that are the least expensive sources of energy and nutrients

CotD information can be used to:

  • Design nutrition and food security interventions aimed at improving the nutrient quality of the diet
  • Promote the least expensive nutrient sources
  • Increasing the availability of the currently expensive food groups, which in turn, could reduce their market price

Example: In Burera district, Rwanda, avocado was identified as a cheap but rich source of energy, fat, vitamin C, soluble B group vitamins, folic acid and copper. Alternatively, yoghurt was identified as the cheapest source of vitamin B12, meeting 96% of total needs for the family and calcium providing 80% of the total need for the family.

Estimating the affordability of the diets by wealth group using HEA income and expenditure data can be used to identify those most at risk of insufficient economic access to a nutritious diet and, thus, most in need of food security and/or nutrition interventions.

This vital diet affordability data can also be used to estimate the size of cash transfers for social protection programmes intended to have an impact on nutrition. For example, a Cost of the Diet analysis in Lindi district, Tanzania, found that families in the poorest wealth group could not afford a nutritious diet, estimating that 115% of their total income would be needed to meet their energy and nutrient requirements.
One of the most innovative aspects of the CotD software is that potential interventions can be modelled to estimate their impact on improving the quality and the affordability of the diet. These results can be used to inform and influence nutrition and food security policies and programmes and contribute to both advocacy processes and debates at local, national and global levels.
A CotD analysis in Pakistan found that iron and zinc requirements could not be met by local foods for a 9-11 month old child. The impact of giving this child a sachet of micronutrient sprinkles twice a year for 30 days, six months apart on the quality of the diet was modelled. The software estimated that all the nutrient requirements for the child could be met and the cost of the diet could be reduced by 60% as a result of this intervention.

Regular CotD assessments can be used help understand changes in food and nutrition insecurity in particular contexts and can act as early warning indicators within food security and nutrition early warning systems.
A CotD analysis is most useful when chronic undernutrition and micronutrient deficiencies have been identified as nutritional problems and when the availability or affordability of nutritious foods are likely to be among the underlying causes.

A Cost of the Diet assessment is most useful when chronic malnutrition and micronutrient deficiencies have been identified as a nutritional problem and the availability or affordability of nutritious foods are likely to be among the underlying causes. Once data collectors are trained and communities mobilised, cost of the diet assessments can be completed on a regular basis. Assessments can be done as part of a situation analysis in order to understand the causes of malnutrition. In addition regular assessments can also be incorporated into nutrition/food security surveillance systems

The Cost of the Diet analysis software and the guidelines are free to use. However, we do request that whenever you use Cost of the Diet analysis in reports/publications, you reference the method in the following way:

“Analysis was done using Save the Children UK’s Cost of the Diet method”.

We are keen to explore the ways that the Cost of the Diet can be used as part of programming, research and advocacy. If you have any suggestions. feedback or would like a copy of the software, please contact the Hunger Reduction and Livelihoods team at Save the Children UK at:


Cost of the Diet Software Guidelines

This guide aims to provide a Cost of the Diet practitioner with the information required to run a full Cost of the Diet assessment.

These guidelines and the Cost of the Diet software are free to use and can be downloaded from

A French version of this guide and the Cost of the Diet reporting guidelines are available on request by contacting

The guidelines can be accessed by clicking the above icon.

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