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The Probability Distribution Framework for estimating the Prevalence of Undernourishment

Exploding the Myth of the Bivariate Distribution

Year of publication 2007

Product type Document

Edition 1

Synopsis (short abstract) In his pioneering study carried in the early 1960’s, Sukhatme had formulated the estimate of the prevalence of undernourishment in a population within a bivariate distribution framework where dietary energy consumption (DEC) and dietary energy requirement (DER) are considered as random variables. The evaluation of the formula required the specification of the joint distribution of DEC and DER. In the absence of data on the joint distribution Sukhatme had, as an approximation, formulate d the estimate within a univariate distribution framework involving the distribution of DEC and a cut-off point reflecting the lower limit of the distribution of DER. FAO’s methodology for estimating the prevalence of undernourishment has been traditionally based on this univariate distribution framework. However, since this approach appeared to ignore the risk of undernourishment at DEC levels overlapping the range of variation of requirement, it has been criticised as yielding an und erestimate of the magnitude of the problem of undernourishment. In view of this some analysts have attempted to apply the bivariate distribution framework by modeling the joint distribution of intake and requirement. Others have applied the univariate distribution framework but used the average DER requirement rather than the lower limit of the distribution of DER as the cut-off point. All these attempts have led to very high estimates of the prevalence of undernourishment. In further studies undertaken in the 1970’s Sukhatme has attempted to justify the univariate distribution framework that he proposed earlier by postulating the theory of intra-individual variation in energy requirement which implies that an individual cannot be considered to be undernourished or overnourished as long as his or her DEC is within the range of variation of DER.

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