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Overview: interpreting anthropometric data in a food security context

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Aims of this presentation: 1. To show that, with some exceptions, it is only possible to interpret anthropometric survey data if the food security context is understood. 2. To open the discussion on food security: a much used term but one which is used in different ways by different organisations, and on which as yet there is no agreed method or best practice.

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The exceptions: Anthropometric survey results can usually be interpreted without information on food security: Where repeated surveys are used to monitor trends. In the (rare) situation where there is complete control of food security e.g. the population is wholly dependent on food aid, or the situation is so bad as to demand that food is supplied.

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Prevalence of malnutrition in Mchinji, Malawi, December 2001. Weight-for-height 11.8 % (7.2-16.4%) 3.8 % (1.9% - 5.7%) < - 2 SD < -3SD or oedema

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The estimate of malnutrition is much higher than the reference values: it is known that in 2001 maize production in Malawi fell by 20-30% & maize prices have increased. The findings could be interpreted to mean that: people are short of food, nutritional status has declined and food aid should be supplied. the findings are unexceptional - oedema rates tend to rise at the end of each year. Problems with interpretation: abnormal or not, it will take 2-3 months to import food in quantity. As the next harvest is due in March 2002, it is reasonable not to take any action.

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Food security: what do we need to know in order to interpret anthropometric surveys? How has an event e.g. crop failure, price change, affected peoples ability to get food? How is peoples ability to get food likely to evolve in future?

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The anthropometric outcome depends (disease aside) on people's access to food, not on the aggregate supply of food. In practice peoples ability to acquire food depends partly on the overall supply: but even if food supply is adequate, or in gross surplus, it does not mean that all people have access to it. People can and do starve in countries that produce surpluses of food. Food supply or access to food?

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Food security Access at all times to enough food of a sufficient quality to ensure an active healthy life. World Bank.

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Best practice in food security? 1. Food balance & crop based systems. 2. Indicator systems use proxy indicators of food availability/access e.g prices, rainfall, crops. 4. Algorithmic methods typically multivariate equations which seek to predict e.g. nutritional status, from measures of livestock holdings, crop production etc. 3. Livelihood systems. Systems which attempt to understand and quantify the impact of a shock on the ability of households to acquire food.

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1. Food balance & crop based systems. Food availability decline Failed crops = failure of food supply = hunger = a fall in nutritional status. Food balance Production + stocks + imports - losses - estimated population requirement = surplus or deficit

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Problems with food balance/ crop methods: It is difficult/ impossible to estimate some variables accurately (e.g. crops, privately held stocks, unofficial imports) There may be enough food, but it may be in the wrong place. Fundamentally: in most locations many people do not depend wholly, or at all, on crop production for food - therefore they may be more or less unaffected by crop failure.

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2. Indicator methods Use easily collected/ obtained information e.g. from routine government sources, which is thought to be a proxy for food supply/ access There are few practical indicators available (precipitation, crop production, prices). Data may be dated, inaccurate or collected in unsuitable locations e.g. towns. Indicators are not in fact always easy to collect. Problems:

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Indicators can only be interpreted if the relationship between the indicator and peoples economy is known. e.g. If a household does not depend on the market for food, or has no cash, an increase in the price of food may be irrelevant.

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3. Livelihood methods - the household economy approach: Based on: observed sources of household cash and food income: within defined populations, usually of households. within populations by wealth group e.g. poor, better off The aim is to calculate the ability of households to maintain their food access in the face of a shock and the relationship between households (e.g. gift), and between households and the wider context - markets, wild foods

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Problems with the Household Economy Approach: Requires data collection: not all agencies have the people/ skills/ cash to do this. Advantages: 1. It works. In a recent review of all (14) SC UK cases where a prediction was made and information was available on the outcome, the prediction and outcome were consistent. 2. It also gives an estimate of who will be affected, how severely they will be affected & when they will be affected.

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December 2001. Nutritional status in Salima ( - 3SD) 9.3 % (< -3 SD or oedema) 4.8%