Assessment of dietary sodium intake using a food frequency questionnaire and 24‐hour urinary sodium excretion: a systematic literature review

Food frequency questionnaires (FFQs) are often used to assess dietary sodium intake, although 24‐hour urinary excretion is the most accurate measure of intake. The authors conducted a systematic review to investigate whether FFQs are a reliable and valid way of measuring usual dietary sodium intake. Results from 18 studies are described in this review, including 16 validation studies. The methods of study design and analysis varied widely with...