Background: The metabolic impact of poor diet quality in cystic fibrosis (CF), coupled with a rise in obesity and modulator-induced weight gain, is a growing concern. Our study aimed to understand knowledge and perspectives regarding dietary changes on modulators, and how measured nutrient intake changes with different dietary patterns in response to diet education. Methods: A cross-sectional survey was administered to 82 adult CF patients at the University of Alabama Birmingham. A subset of 10 participants received diet education and followed two diet patterns sequentially: a general healthful (GH) diet and a high fat (HF) diet. Three-day diet records were analyzed following each diet pattern. Results: A total of 82 adults responded to the survey and 42% of respondents reported making healthful dietary changes on modulators. Only 56% of respondents were able to correctly identify which foods contained fat. Diet record analyses showed a significant decrease in energy intake and fat intake on the GH diet compared to the HF diet. Baseline HEI scores improved significantly (p=0.0254) following education on a GH diet pattern, but were significantly lower following the HF diet (p=0.0179). Conclusions: While nearly half of survey respondents reported making healthy dietary changes on modulators, basic nutrition knowledge deficits persist. Measured diet quality was poor at baseline and significantly improved after receiving an educational session on GH eating. Findings highlight the need for targeted, basic education on GH eating patterns in the clinical practice and larger studies of nutrition interventions for improving diet quality in CF.