Introduction: Unhealthy dietary patterns that cause disease have been identified by the Centers for Disease Control (CDC) as one of the seven behaviors that contribute to the leading causes of morbidity and mortality. An effective Health Curriculum in school systems is one way to address these patterns among youth; however, one of the common barriers to effective instruction is lack of proper training for teachers, resulting in low teacher self-efficacy and subsequent curricular implementation. Purpose: The purpose of this research was to determine the effectiveness of nutrition in-service training guided by adult learning and constructivist theories on both teaching self-efficacy and intentions to teach nutrition education. Methods: The study was conducted in a large metropolitan setting and approved by the IRB. Two groups of teachers responsible for Health Education participated. The intervention group (n=30) participated in a day-long training designed to prepare them to teach the Michigan Model for Nutrition Education, grades 7-8. The control group (n = 29) was a similar group of teachers that received no training. A 42-item valid and reliable questionnaire was used to determine differences, consisting of questions assessing self-efficacy, (the person's belief about his or her capability to perform a certain behavior), outcome expectancy (that the behavior will lead to a desired outcome) and outcome value (that the outcome is meaningful). Demographic questions addressed years of experience teaching health, lessons most often taught, and intent to teach topics in the future. Each set of questions was totaled giving a subscale score which was analyzed separately using a 2-groups (Intervention vs. Control) by 2-times (pre-post) ANOVA with repeated measures on the time factor. Analysis/Results: There were 2 significant main effects for time and group and a significant group x time interaction in self-efficacy and outcome expectancy. There was also a significant time main effect for outcome value and intent to teach. Post hoc analysis revealed that the intervention group scored significantly higher than the control group in all four areas, post-intervention. Conclusions: Results of this study indicate that in-service training increased the number of lessons the intervention teachers intended to teach, as well as their self-efficacy. Because self-efficacy has been strongly linked to teacher effectiveness, efforts should be directed at providing continual training for teachers based on the CDC risk behaviors. Keyword(s): health education K-12, nutrition, professional preparation