The Swedish National Agency for Education states that educational provision should involve pupil opportunities for interdisciplinary work and the experience of learning in different ways. In this context, the current study aimed to explore the actual operation of interdisciplinary teaching (IDT) in Swedish compulsory schools, i.e. from preschool (6 years) to grade 9 (16 years) regarding nutrition and health. To investigate this, two web-based nationwide questionnaires were sent out in 2014 to compulsory schools in Sweden. One questionnaire was aimed at teachers in five subjects: Home and Consumer Studies (HCS), Natural Science Subjects (NSS) (Biology, Chemistry, Physics), and Physical Education and Health (PEH). The second questionnaire was for school principals. A total of 388 teachers and 216 principals answered the respective questionnaire. The study showed that 40% of the teachers and 59% of the principals reported that their school worked in an interdisciplinary way regarding nutrition and health education. Practical scheduling problems and a lack of time for planning were seen as the main barriers by both teachers and principals, but to a much larger extent by teachers. A prerequisite for successful IDT is that teachers have a chance to meet and plan, and this study indicates that frame factors have a critical impact on what is possible regarding IDT in Swedish schools. It is crucial that principals appreciate their part in facilitating IDT. Increased interdisciplinary teaching for nutrition and health (IDT-NH) might increase school potential for the better integration of knowledge and understanding about the importance of lifestyle for health, the environment and society.