Development and validation of the FiberScreen: A short questionnaire to screen fibre intake in adults

BACKGROUND: Health effects of dietary fibres are the topic of many studies. Eligibility criteria often include a certain fibre intake, which requires dietary screening during recruitment. However, dietary assessment methods are extensive and burdensome for both the researcher and participant. Therefore, we developed and validated a short questionnaire (FiberScreen) to screen fibre intake. METHODS: The initial five‐item questionnaire assessed fruit, vegetable, whole grain, pasta/rice/potato and legume intake. The optimised FiberScreen included 18 items, which further specified intake of the above‐mentioned categories, and included nuts and seeds. The FiberScreen was completed during two fibre promoting interventions. In Study A, participants without constipation completed the five‐item FiberScreen and a food frequency questionnaire (FFQ) during screening (n = 131), and the 18‐item FiberScreen and a FFQ at 3‐month follow‐up (n = 87). In Study B, 29 constipated participants completed the 18‐item FiberScreen at screening and a FFQ during the first study visit. RESULTS: The fibre estimate from the five‐item FiberScreen and the FFQ was moderately correlated (r = 0.356, p < 0.001). Importantly, the 18‐item FiberScreen and FFQ, when data of both studies were combined, had a strong correlation (r = 0.563, p < 0.001). The 18‐item FiberScreen had a lower fibre estimate compared to the FFQ (Δ = 1.2 ± 5.9 g, p = 0.030) but the difference was relatively small. Bland–Altman plots showed a good agreement between the questionnaires. Completion time of the 18‐item FiberScreen was 4.2 ± 2 min. CONCLUSIONS: The 18‐item FiberScreen is a suitable short screening questionnaire for ranking the fibre intake of adults. The 18‐item FiberScreen can help to reduce screening burden for both the participant and researcher.