World need for protein

On the basis of the 1973 FAO/WHO recommendations for average calorie requirements and safe protein allowances for healthy individuals, both calorie and protein intakes are generally deficient in the lower socioeconomic groups of developing countries, with calories apparently the more limiting in most cases. However, extensive data available since 1973 indicate that the 1973 protein allowances for healthy adults approximated the mean rather than the mean plus two standard deviations as intended. For those individuals in developing countries who are frequently unhealthy, requirements may be even higher. Children have considerably higher protein requirements for catch-up growth following episodes of acute infection; failure to obtain sufficient protein appears to be a major factor in the pemanent stunting of such children. Requirements for dietary energy increase much less for catch-up growth than requirements for protein. Comparing calorie intakes with international estimates of requirements has limited validity because of the human capacity to adjust to a decreased dietary energy intake by reducing physical activity. No comparable adaptation is known for low dietary protein intakes; instead, under the conditions responsible for limited food availability, protein requirements are likely to increase because of acute and chronic infections. Although differences in protein quality can be demonstrated by experimental animal and human studies in which protein intake is grossly deficient, little difference is detectable in studies where protein intake is at requirement levels. Thus, soy and other legume and oilseed protein sources can replace animal protein to any degree in human diets.