Although nutrition-related health education policies exist at national, state and local levels, the degree to which those policies affect the everyday practices of health education teachers who are charged with executing them in schools is often unclear. The purpose of this study was to examine the nutrition-related health education policy matrix that affected one urban school district, the health education teachers' awareness of those policies, the impact of nutrition policies on teachers' instruction and challenges teachers perceived in executing comprehensive nutrition education. The study used interpretive ethnography to examine the educational contexts and perspectives of 27 health educators from 24 middle schools in one urban district in the Midwestern United States. Data were collected through school observations, interviews with key personnel and document collection. We found that a network of nutrition-related education policies governed health education teachers' instruction, but that teachers were uniformly unaware of those policies. Without institutional coherence and clear directives, health education teachers taught little nutrition content, primarily due to poor training, professional development, instructional resources and administrative accountability. The results are discussed in light of the enormous challenges in many urban schools and the need for nutrition education professional development.