Human protein requirements: A brief update

Abstract

In the 1950s and 1960s the risk of protein deficiency in the diets of most developing country populations, both in absolute terms and relative to calories, was considered to be high. An FAO/WHO expert committee that met in 1971 proposed a protein allowance value 20% lower than that previously recommended. Nutritionists and economists accepted this new value, recalculated the risk from dietary intake data, and concluded that protein deficiency was not a problem. This conclusion was reinforced by the concurrent virtual disappearance of the severe form of protein deficiency, kwashiorkor, as developing country conditions improved. However, metabolic studies coordinated by UNU in 16 countries soon showed that the protein required for sustained normal functioning was one-third more than that proposed in the report of the 1971 committee. This higher value was accepted in the 1985 FAO/WHO/UNU expert consultation report on energy and protein requirements. In addition, infections, highly prevalent under conditions of poverty, increase protein losses and often decrease protein absorption. Although it is true that when people can consume enough of their traditional diet to meet energy needs, protein needs are also usually met, problems arise when, because of poverty or illness, people cannot consume their traditional diets. New data on protein digestibility and on protein quality are recognized in a 1991 FAO/WHO expert consultation and a 1994 International Dietary Energy Consultative Group (IDECG) workshop. Protein requirements are re-evaluated in this paper on the basis of these considerations.