Processed foods questionnaire reliably assesses consumption in adult IBD patients

A recent study has shown the validity and reliability of a processed foods frequency questionnaire (PFQ) in evaluating processed foods consumption in patients with inflammatory bowel disease (IBD).

In addition, the PFQ can be used to assess the association between processed food consumption and IBD aetiopathogenesis.

In this prospective single-centre study, the authors developed a PFQ and assessed its reliability and validity. Eighty-six adult IBD patients were recruited and asked to fill-in this PFQ. The authors then categorized food intake into three groups of food levels: unprocessed, processed, and ultra-processed.

Reliability was assessed by comparing the PFQ results of each patient at two time points, and validity by comparing the PFQ results to a 3–7-day food diary (FD) and by comparing urine sodium as a biomarker for the high intake of sodium, which is usually present in processed foods.

Intraclass correlation of 0.75–0.88 for the different food processing levels indicated good test–retest reliability of the PFQ.

Validity was fair to strong, as assessed by correlations for different levels of processed food intake between FDs and PFQ (range, 0.43–0.64; p<0.001). This was further supported by higher mean urine sodium levels in patients with high vs low processed foods consumption (104.57±53.26 vs 78.62±39.08 mmol/L; p=0.022).

Agreement was fair between FD and PFQ in classifying patients to high and low processed food consumption (Kappa, 0.23–0.35).