Objective: Personality traits are related to numerous health outcomes and health-related behaviors. To date, however, little is known about how personality traits are associated with dietary behavior, an important aspect of lifestyle in the current "toxic food environment." The present study investigated the associations of between Five-Factor Model personality traits, dietary patterns, and body mass index (BMI). Methods: The sample consisted of 1,091 members of Lothian Birth Cohort 1936 tested at age 70 years. Dietary patterns were measured using a detailed and validated food frequency questionnaire (FFQ). Principal components analysis of the FFQ items identified four dietary dimensions, which were named 'Mediterranean style diet,' 'health aware diet,' 'convenience diet,' and 'sweet foods'. Personality traits were measured with NEO Five-Factor Inventory. The effects of childhood intelligence, education, and sex were controlled. Results: Endorsing the Mediterranean style diet dimension was associated with high Openness and Extraversion, and low Neuroticism. High scores on the health aware diet dimension were associated with high Agreeableness and Conscientiousness. Endorsing the convenience diet dimension was associated with low Openness and high Neuroticism. Preference for sweet foods was associated with low Openness. High BMI was associated with high scores on the convenience diet dimension and low Conscientiousness. Conclusions: Personality traits, especially Openness, are associated with dietary patterns in older age. The pattern of findings may indicate that, in older people, dietary habits may be less related to how controlled they are and more related to their levels of openness and emotional and social adjustment. Policy implications are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved).