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Providing perspectives on recent research into vitamins and nutritionals


CDC Study finds Sodium Intake is Lower than Expected

By Michael McBurney

New study finds 24h dietary recall overestimate sodium and potassium intake. Using objective measures of nutritional status, in this case 24 hour urinary collection, Mercado and colleagues suggest that the discrepancy may partially reflect inaccurate food databases. In other words, foods may contain less than expected amounts of sodium.

Dietary records and 24 h urine samples were collected from 402 adults (18-39 y) to estimate usual daily intakes and excretion of sodium and potassium.  Results published in the American Journal of Clinical Nutrition highlight the inaccuracy of using dietary records to assess nutritional status. Correlations between dietary intake and urinary excretion were low. Based on objective biological measures, dietary recall estimates are a ‘weak’ predictor of sodium and potassium intake.

Have you ever kept a food record? It is tedious. Underreporting is common and leads to inaccurate estimates of food intake.  The problem of accurately estimating nutrient intake is compounded by the fact that food databases list only a fraction of the food products available to consumers. How can nutrient intakes be estimated when people don’t honestly report the amounts consumed and researchers don’t have food compositional data for much of what is consumed?

Nutrition science is at a tipping point. With emerging portable technologies to assess nutritional status in saliva, blood or urine quickly and cheaply, researchers (and policy makers) need to transition away from using crude dietary assessment tools.

2015 is approaching. Nutrition policy (and personal guidance) should be guided by biological measures of nutritional status.

Main Citation

Mercado CI, Cogswell ME, Valderrama AL, Wang C-Y, Loria CM, Moshfegh AJ, Rhodes DG, Carriquiry AL. Difference between 24-h diet recall and urine excretion for assessing population sodium and potassium intake in adults aged 18-39 y. 2014 Am J Clin Nutr doi: 10.3945/ajcn.113.081604

Other Citations

Archer E, Hand GA, Blair SN. Validity of u.s. Nutritional surveillance: national health and nutrition examination survey caloric energy intake data, 1971-2010. PLoS One. 2013 Oct 9;8(10):e76632. doi:10.1371/journal.pone.0076632.

Hall OM. Smarter phones, smarter solutions: College researchers are tapping the power and reach of mobile devices to solve pressing issues of malnutrition and food distribution. 2014 Human Ecol 41(2): 13