Diet quality in Brazilian adolescents with cystic fibrosis

To describe the quality of the diet and its relationship with lung function and nutritional status in adolescents with cystic fibrosis (CF).

A questionnaire was applied to 47 adolescents (12-19 years old) followed at a university reference center. Lung function impairment was classified as mild (FEV1pp ≥ 60%), moderate (FEV1pp 41-59%), or severe (FEV1pp < 40%) using spirometry. Food consumption frequency was classified as rarely, 1-2 times/week, 3-4 times/week, or ≥ 5 times/week. Linear regression analysis was used to model the relationship between lung function, BMI/age Z-score, and food frequency. Principal component analysis (PCA) was performed to identify patterns of diet quality.

The mean BMI/age Z-score was -0.62. Approximately 60% of adolescents had FEV1 ≥ 60%, and 21% had severe impairment (FEV1 < 40%). Better BMI/age Z-score was observed in groups with higher consumption frequencies of vegetables and fruit (≥ 5/week), white meat (> 3-4/week), and oil (> 3-4/week). Linear regression models identified significant relationships: BMI/age Z-Score = -3.25+ 0.8182*meat_b+0.5082*vegetables_fruit (p < 0.001): Increased white meat, fruit, and vegetable consumption positively influenced the BMI/age Z-Score; lung function = 0.6927 + 0.3356*vegetables-0.2406*fruit_vegetables-0.4550*fast_food (p < 0.001): Lower consumption of fruit and vegetables and higher fast-food intake were associated with more severe lung function; and lung function = 0.39376 -0.32345 *ZSCORE (p < 0.0001): The BMI/age Z-Score positively influenced lung function. PCA confirmed the positive relationship between fruit, vegetables, and white meat consumption and BMI/age Z-score.

Higher consumption of fruit, vegetables, and meat has a positive influence on the BMI/age Z-score and lung function among adolescents with CF.