Objectives: Orthodontists generally recommend avoidance of certain foods during fixed appliance (FA) treatment, based on anecdotal information. This study aimed to identify the dietary preferences and experiences of patients undergoing FA treatment as a step toward the preparation of evidence-based dietary guidelines. Material and Methods: Questionnaires regarding dietary preferences and experiences of patients undergoing FA treatment were applied to a convenience sample of 38 adolescents (12 M; 26 F). Open-ended responses were summarized and visualized in a world cloud generator. 5-point Likert and Visual Analog Scales (VAS) were used to record the closed-ended responses. Descriptive statistics and multivariate analysis of variance were used to analyze questionnaire findings. Results: Lollies, apples, and nuts frequently caused problems with FA. The most frequent reason for avoiding certain types of food was worry about appliance breakage, followed by pain and sensitivity. VAS scores indicated that toffee and caramel scored highest (65.1% F and 54.1% M) for discomfort followed by corn on the cob (64.4% F and 48.7% M) and apples (56.6% F and 55.3% M). VAS scores did not differ significantly between the sexes (P > 0.05). Nearly, a quarter of the sample reported that FA negatively affected their eating behaviors, causing pain and discomfort during eating. No sex differences (P > 0.05) were found for negative experiences with food. Conclusion: Dietary preferences and experiences of patients undergoing FA treatment were identified concerning a New Zealand diet profile. A future study with a larger sample size will help formulate evidence-based dietary guidelines during FA treatment.