Development and validation of a short questionnaire to assess sodium intake

Objectives: To develop and validate a short, food frequency questionnaire to assess habitual dietary salt intake in South Africans and to allow classification of individuals according to intakes above or below the maximum recommended intake of 6 g salt/day. Design: Cross-sectional validation study in 324 conveniently sampled men and women. Methods: Repeated 24-hr urinary Na values and 24-hr dietary recalls were obtained on three occasions. Food items consumed by > 5% sample and which contributed e 50 mg Na/serving were included in the questionnaire in 42 categories. A scoring system was devised, based on Na content of one index food per category and frequency of consumption. Results: Positive correlations were found between Na content of 35 of the 42 food categories in the questionnaire and total Na intake, calculated from 24-hr recall data. Total Na content of the questionnaire was associated with Na estimations from 24-hr recall data (r = 0.750; P