The Potential Impact of Changes in Income Distribution on Food Demand and Human Nutrition: Comment

Pinstrup-Andersen and Caicedo are to be applauded for their research endeavors in the area of income redistribution and dietary adequacy in developing countries. Their analysis projected a possible impact on calorie and protein availability by income stratum caused by changes in existing income distributions. The report is hopefully a step forward to improvement of public policy directed toward the goal of improved human nutrition. The purpose of this comment is to clarify several points of nutritional nature about which there appears to be a basic misunderstanding. Although the type of data used is not specifically defined in the paper, the reader is led to assume the data used for the analysis are consumption data as opposed to dietary intake data. If such is the case, PinstrupAndersen and Caicedo have consistently misused the word "intake." Intake has physiological implications and refers to the ingestion of food. The authors should have used the term "consumption" because this term refers only to the quantities of foods used from the home food supply. The form in which the food enters the home rather than the form in which it is eaten or otherwise used is the amount recorded. Due to plate waste, presence of meal guests, giving food to pets, or discarding it for any reason, the quantities of foods, and thus nutrients, calculated as being consumed by the household may overstate the quantities of foods (nutrients) actually eaten. An even more perplexing problem with the research is the misinterpretation of the information referenced from Rueda-Williamson. The figures presented in table 2 are based on provisional allowances and not on daily requirements as PinstrupAndersen and Caicedo reported. Daily nutritional requirements are experimentally determined minimum amounts of nutrients necessary to support health and well being. The actual values for human requirements vary according to age, sex, and weight. On the other hand, provisional allowances are set under the assumption that requirements vary among individuals and that the variation follows a normal distribution. Allowances tend to be set high enough to meet the nutritional requirements for nearly all healthy persons in each age group in the population. There are no universal allowances; for example, protein allowances vary from country to country with a man between ages twenty and twenty-nine weighing between 65 and 70 kilograms (kg) having, an allowance of 65 grams in the USA, 70 grams in Australia, and 68 grams in Colombia. The FAO has developed a set of standards which are the most universally accepted; these standards state that a man of age twenty-five weighing 65 kg has a protein allowance of 46 grams. If the researchers' analyses for table 2 were based on FAO standards, there would be no nutritional risk for any income stratum. Even when the analysis is based on the allowances specified for Colombia, there is no basis for Pinstrup-Andersen and Caicedo to conclude that the low income people of Colombia have calorie and protein deficiencies. Mathematically, the two lowest income strata would be found to be below 100% of the specified Colombian allowances, but failure by a population group to meet 100% of the allowance does not necessarily establish the presence of deficiencies. The authors have no basis for speculating on these deficiencies for the above-mentioned reasons and, also, because their analyses are based on consumption data and not dietary intake data. The most they can conclude is there exists a possibility of low income people in Colombia being at nutritional risk since protein and calorie consumption are somewhat less than allowances.