Background: Adults with intellectual disabilities living in residential houses have a high prevalence of obesity which is related to poor dietary habits. Aim: The aim of this study was to assess supporting staff`s thoughts and experiences on factors influencing their opportunities to promote a healthy diet in adults with intellectual disabilities. Methods: 13 supporting staff members were recruited from 11 different residential houses in a community. Concept Mapping methodology was used, including group interviews, sorting, rating statement and analysing the results. Results: Seven clusters most accurately captured the ideas of the supporting staff`. 'Attitudes', 'Facilitating a healthy diet', 'Practical cooking skills' and 'Applied dietary knowledge' were the four most important. Conclusions: Multiple factors influence the opportunities of supporting staff to promote a healthy diet. A holistic approach addressing all relevant factors is necessary when developing interventions to address this complex issue in persons with intellectual disabilities.