Vegetarian and Vegan Diets: Weighing the Claims

Abstract

Vegetarian diets are becoming increasingly popular in developed countries. While no reliable prevalence data for vegetarian populations exist, results of polls and surveys have reported population prevalence of between 1 and 10% in the European Union, the United States, and Canada (http://www.evana.org/index.php?id=70650). A recent study in the United States reported that 2.8% of respondents never ate meat, poultry, fish, or other seafood, although 4–10% would classify themselves as vegetarian (www.vrg.org/journal/vj2006issue4/vj2006issue4poll.htm). Vegetarian diets are often heterogeneous in nature, involving a wide range of dietary practices. These are summarized in Table 20.1. Even within classifications of dietary practices, there can be a high level of variability depending on the individual dietary restriction(s). Vegetarian or vegan diets may be practiced for a variety of reasons, including health, cultural, philosophical, religious, and ecological beliefs, or simply because of taste preferences. This chapter will discuss vegetarian and vegan diets and their impact on human health.