ABSTRACT
Worldwide an estimated 2 billion people live primarily on a meat-based diet while an estimated 4 billion people live primarily on a plant-based diet (Pimentel et al., 1999). The shortage of cropland, freshwater, and energy resources requires that most of the 4 billion people live primarily on a plant-based diet; however, there are serious food shortages worldwide. For instance, the World Health Organization recently reported that more than 3 billion people are malnourished in the world (WHO, 2000). This is the largest number and proportion of malnourished people ever recorded in history. In large measure, the food shortage and malnourishment problem are primarily related to rapid population growth in the world in addition to the declining per capita availability of land, water, and energy resources required for food production (Pimentel and Pimentel, 2003).
