Dietary salt intake in the Australian population

Objective: To update the estimate of mean salt intake for the Australian population made by the Australian Health Survey (AHS).

Design: A secondary analysis of the data collected in a cross-sectional survey was conducted. Estimates of salt intake were made in Lithgow using the 24 h diet recall methodology employed by the AHS as well as using 24 h urine collections. The data from the Lithgow sample were age- and sex-weighted, to provide estimates of daily salt intake for the Australian population based upon (i) the diet recall data and (ii) the 24 h urine samples.

Setting: Lithgow, New South Wales, Australia.

Subjects: Individuals aged ≥20 years residing in Lithgow and listed on the 2009 federal electoral roll.

Results: Mean (95 % CI) salt intake estimated from the 24 h diet recalls was 6·4 (6·2, 6·7) g/d for the Lithgow population compared with a corresponding figure of 6·2 g/d for the Australian population derived from the AHS. The corresponding estimate of salt intake for Lithgow adults based upon the 24 h urine collections was 9·0 (8·6, 9·4) g/d. When the age- and sex-specific estimates of salt intake obtained from the 24 h urine collections in the Lithgow sample were weighted using Australian census data, estimated salt intake for the Australian population was 9·0 (8·6, 9·5) g/d. Further adjustment for non-urinary Na excretion made the best estimate of daily salt intake for both Lithgow and Australia about 9·9 g/d.

Conclusions: The dietary recall method used by the AHS likely substantially underestimated mean population salt consumption in Australia.