Continuous subcutaneous insulin infusion (CSII) can improve glycaemic control and dietary flexibility compared with conventional insulin therapies. There is little information on whether users are utilising this increased dietary flexibility, and whether dietary quality is affected. METHODS: A pre-post observational study was undertaken in 28 children and adolescents with type 1 diabetes commencing CSII. Meal pattern and dietary composition was examined from 3-day food diaries completed before and 3-6 months after CSII commencement. Participants completed the Diabetes-Specific Quality of Life for Youth Short Form, and body mass index z-score, and glycated haemoglobin were measured. A second posttest was undertaken at 18 months with those who were still on CSII and contactable (n = 18). RESULTS: Energy and macronutrient intake before and 18 months after CSII commencement were unchanged. Mean snacking events decreased significantly by 1.2 snacks per day (P = 0.009), as did the percentage energy derived from snacks (28.8 , 95 confidence interval (CI) 21.5-36.1 vs. 19.3 , 95 CI 13.2-25.4; P = 0.045). Diabetes-Specific Quality of Life for Youth Short Form score was not significantly affected by pump commencement (25.9 95 CI 18.2-33.6), and body mass index z-score remained similar before and after CSII. Glycated haemoglobin decreased by 0.5 in the 3-6 months following CSII commencement, but was similar to baseline at 18 months. CONCLUSIONS: This study demonstrates that the commencement of CSII did not lead to an abandonment of healthy eating principles, and that patients utilised the increased dietary flexibility to make changes to their snacking pattern.