ABSTRACT
Vegetarian diets of varying degrees of restriction may be adopted for cultural, religious, or health reasons. In 2009, an estimated 3.4% of adults in the United States reported no consumption of meat, poultry, or seafood and thus could be described as vegetarian, while 0.8% omitted all animalderived products (including milk, eggs, and honey) and could be described as vegan [1]. The ofcial position statement of the American Dietetic Association states that “Appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benets in the prevention and treatment of certain diseases” [2]. Specically, vegetarian diets have been linked with a decrease in the risk of ischemic heart disease and other obesityrelated disorders [3,4] in some but not all studies. The topic of vegetarian diets and obesity has been reviewed by one of the authors and others; in general, body mass index (BMI) has been found to be lower in both men and women in vegetarians vs. nonvegetarians [5-8]. The discussion that follows in this chapter emphasizes results published within the last 10 years. This chapter rst describes
Introduction .................................................................................................................................... 457 Studies of Vegetarian Diets and Obesity ........................................................................................ 458
Observational Studies ................................................................................................................ 458 Factors Affecting the Impact of a Vegetarian Diet .................................................................... 462 Intervention Studies ..................................................................................................................463
