ABSTRACT
Besides adjusting to physical stressors, our species has had to cope with the vicissitudes of life on the food chain: finding food while avoiding being eaten. Finding sufficient food continues to be, at least in certain circumstances, a serious problem for many human populations. Predation by lions, tigers, bears, and other carnivorous mammals is much less of an issue for our species in recent millennia, but we still face the challenge of being the preferred food for a large variety of microbial organisms. Thus, this chapter will explore in general terms how humans adapt to the biological stresses caused by malnutrition and infectious disease. As will become evident, these two stresses are interrelated.
Malnutrition, defined as poor nutrition, whether from too little food, too much food, or a poorly balanced diet, may be seen as evidence for a failure in adaptation. This failure may be at the level of the individual, of a family, or of an entire population. In the terms of the single-stressor model used in the previous chapter, the behavioral/cultural buffer against malnutrition consists of all the foodgetting activities that people use, from foraging for wild plants and animals, to managing vast agricultural systems, to trading for or buying food items in markets. It is only when these various activities are unsuccessful that human bodies are placed in a microenvironment that leads to malnutrition. The lack of success could be due to many factors, including environmental changes, such as persistent droughts; poor methods of production, such as overexploitation of garden plots that leads to long term degradation of soils; and/or influences from external human forces, such as tenantship of land with wealthy landowners skimming much of a farmer’s food production. In fact, much of the problem with malnutrition in the world is due to social inequalities that leave many individuals without the resources to produce sufficient food for themselves and their families.
