Cost of Diets - assessing the potential contribution of agricultural biodiversity

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Linear programming: a modeling tool to assess the potential contribution of agricultural biodiversity to nutritious diets at affordable cost – an example from eastern Baringo District, Kenya Céline Termote, PhD Tropentag, September

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Bioversity International researcher Céline Termote spoke about her research on the Cost of Diets at Tropentag 2014 that took place in Czech Republic. In her presentation she spoke about a modeling tool to assess the potential contribution of agricultural biodiversity to nutritious diets at affordable cost, highlighting a particular case study from eastern Baringo District, Kenya. Learn more: http://www.bioversityinternational.org/fileadmin/user_upload/online_library/publications/pdfs/Role_of_wild__neglected_and_underutilized_foods_in_reducing_the_cost_of_a_nutritionally_Poster_1595_01.pdf

Transcript of Cost of Diets - assessing the potential contribution of agricultural biodiversity

Page 1: Cost of Diets - assessing the potential contribution of agricultural biodiversity

Linear programming: a modeling tool to assess the potential contribution of agricultural biodiversity to nutritious diets at affordable cost – an example from eastern Baringo District, KenyaCéline Termote, PhD Tropentag, September 2014

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Introduction

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Whole of diet approach

•ABD assessments document what foods are available in a certain region

•Dietary intake surveys document what is actually being consumedÞ Diets in poor countries are

frequently unbalanced or deficient in nutrients such as iron, zinc, calcium, riboflavin, vitamin A and vitamin C

Þ Is this deficiency due to a shortage of micronutrient-dense foods (availability), economic constraints (access), poor health/care and/or an inappropriate selection of foods (nutrition illiteracy)?

Ecosystem

Species

Genetic

Proteins

Vitamins

Minerals

Carbohydrates

Lipids

Anti-nutrients

Anti-oxidants

Pharmacologically active substances

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Individual choices

Nutrition and health

outcomes

Activity level

Nutrient interactions

Morbidity

Water &

sanitation

….

Biodiversity

availabilit

yNutrient

profile

Accessibility

Culture

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BiodiversityGood nutrition and health

Cultural Identitiy Food taboos

Income

Knowledge Barriers

Incentives

Value chains

Markets

ValuesMorbidity Housing

Water and sanitation

Nutrient interactions

Anti-nutrients

Etc…

Policies

Can the consumer demand for nutritious and healthy foods stimulate biodiversity conservation ?

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Questions?

•Is it possible to design a diet that fulfills all nutritional recommendations for different age groups through the use of locally available foods across the seasons?

•If such a diet is possible, what is the lowest cost combination of these foods that achieve all nutrient requirements?

•Is there a way to take into account cultural preferences (food patterns)?

Requires an assessment of all combinations of available foods to determine which combinations provide the least costly diet while concurrently meeting nutrient intake recommendations including…

Linear programming as an approach to model complex multifactorial problems, in an objective way of assessing these combinations; it is a mathematical approach that optimizes (minimizes or maximizes) a linear function of a set of decision variables, while respecting multiple linear constraints.

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The Cost of Diet tool

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• Developed by Save the Children, UK and based on linear programming work previously carried out by WHO. COD tool is available for free from Save the children, UK

• Uses Excel’s solver function to perform linear optimization of the cost of a modeled diet while respecting a number of ‘nutrient constraints’ based on recommended energy and nutrient requirements (for different ages, sex and acitivity levels)

• 2 databases available in the tool: • World Food Composition Database• FAO/WHO recommended individual energy and nutrient needs

• Data needs: comprehensive list of all available foods and their prices / 100 g edible portion

• Option: minimum and maximum food constraints can be entered by defining the min and max number of times a food can be included in the diet

=> to adress cultural and dietary acceptability• Average portion sizes per age category are available in the tool

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• Other linear programming tools

• Nutrisurvey => compatibility issues

• Optifoods => not yet available, but very promising, optimizes starting from the actual dietary patterns and tries to find

the best solution (meeting nutrient requirements) that differs the less from the actual dietary patterns (cost is only an additional constraint

option)this means less assumptions with regard to culturally acceptable frequencies of consumption and portion sizes

Linear Programming to model diets is commonly used in pet and animal food industries to construct a diet that meets nutrient requirements at a specified cost

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Eastern Baringo District, Kenya example

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Role of wild, neglected and underutilized foods in reducing the cost of a nutritionally adequate diet in the eastern region of Baringo District, Kenya

Project in collaboration with Save the Children UK and the Museums of Kenya

Objective: Documenting the role of wild and underutilized foods in reducing the cost of a nutritionally adequate diet for children aged 6 to 24 months and women.

Methodology:• Ethnobotanical surveys to inventory wild and NUS species• Market price assessments and seasonality• Culturally acceptable average food consumption frequencies and portion sizes• Selection of 5 wild NUS species for modeling in Cost of Diet analysis• Cost of Diet lineair programming to assess the cost of a locally appropriate,

culturally acceptable, cost-optimized, nutritious diet in dry and wet season. Analysis with and without wild NUS foods.

http://www.bioversityinternational.org/index.php?id=19&no_cache=1&user_bioversitypublications_pi1[showUid]=7177

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Percentage of nutrient requirements met by the modeled diet without wild foods (only deficient nutrients are shown) and additional percentage of nutrient requirements met by including all 5 wild foods together or the wild fruit Berchemia discolor apart in the modeled diet for the dry and wet season.

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Role of wild, neglected and underutilized foods in reducing the cost of a nutritionally adequate diet in the eastern region of Baringo District, Kenya• Without wild foods:

•Modeled (optimized) diets were deficient in Fe for all age groups (women and children) during dry season•For infants aged 6 to 8 months: Vit. B6 and Ca deficient during dry season, Fe and Zn deficient the whole year.

•Including all 5 selected wild plant foods in the modelled diet (at a supposed zero cost), could substantially lower the cost of the diets (up to 64% for some age groups) and contributed to meet FAO/WHO recommended nutrient intakes.•Berchemia discolor had the highest impact on the cost

of the diet and on meeting recommended nutrient intakes for Fe.•With or without wild foods, it was not possible to meet all

recommended nutrient intakes in all seasons for children aged 6 to 12 months.

Balanites aegyptiaca

Berchemia discolor

Ximenia americana

Ziziphus mauritiana

Solanum nigrum

http://www.bioversityinternational.org/index.php?id=19&no_cache=1&user_bioversitypublications_pi1[showUid]=7177

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Some challenges

•Food composition data for wild and NUS species not always available how to prioritize for biochemical analysis?

•What is the real cost of wild foods?

•How can cultural preferences and dietary patterns be better taken into account

•How to use the theoretically modelled diets to develop in a participatory way practically feasable, safe, affordable guidelines and/or recipes?

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Research outcome

•Uptake of tool / methodology by researchers, development & extension workers to explore the existing food biodiversity options to improve diet quality

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www.bioversityinternational.org

Thank you

Nutrition and Marketing Diversity ProgrammeCéline Termote; [email protected]