Eating disorder behaviors are prevalent in Latina populations. This study tested Schwartz's (2006) theoretical view that a broad array of personal identities serves as an internal resource during acculturation and prevents internalization of dysfunctional weight related beliefs. Sixty-six Mexican American women completed measures of personal identities, fat self-definition, eating disorder symptoms and acculturation. Results show that few positive and many negative personal identities predict higher eating disorder scores and effects are mediated through the fat self-definition. Characteristics of personal identities may influence internalization of cultural values related to weight. Interventions focused on overall identity may prevent eating disorders in Latinas. (C) 2010 Elsevier Ltd. All rights reserved.