RESUMO
OBJECTIVE: To compare methods for estimating discretionary salt intake, that is, salt added during food preparation and consumption in the home. SETTING: The study was carried out in a rural Guatemalan village. SUBJECTS: Subjects were selected non-randomly, based on their willingness to cooperate. Nine mother-son dyads participated; the sons were aged 6-9 y. INTERVENTIONS: Three approaches for estimating the discretionary salt consumption were used: 24 h recall; collection of duplicate portions of salt; and urinary excretion of lithium during consumption of lithium-labelled household salt. Total salt intake was assessed from the excretion of chloride over 24 h. RESULTS: The mean discretionary salt consumption based on lithium excretion for mothers was 3.9+/-2.0 g/d (mean +/- s.d.) and for children 1.3+/-0.6 g/d. Estimates from the 24 h recalls and from the duplicate portion method were approximately twice and three times those measured with the lithium-marker technique respectively. The salt intake estimated from the recall method was associated with the lithium-marker technique for both mothers and children (Spearman correlation coefficient, 0.76 and 0.70 respectively). The mean daily coefficient of variation in consumption of discretionary salt measured by the three methods, for mothers and boys respectively, were: lithium marker, 51.7 and 43.7%; 24 h recall, 65.8 and 50.7%; and duplicate portion, 51.0 and 62.6%. CONCLUSIONS: We conclude that an interview method for estimating discretionary salt intake may be a reasonable approach for determining the relative rank-order in a population, especially among female food preparers themselves, but may grossly overestimate the actual intake of salt added during food preparation and consumption.
Assuntos
Cloreto de Sódio na Dieta/administração & dosagem , Adulto , Criança , Cloretos/urina , Feminino , Guatemala , Humanos , Entrevistas como Assunto , Lítio/urina , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Cloreto de Sódio na Dieta/metabolismo , Cloreto de Sódio na Dieta/urina , Espectrofotometria AtômicaRESUMO
The use of discretionary salt, which is salt added during cooking and at the table, as a suitable vehicle for iodine intake was assessed by measuring salt consumption using the lithium-marker technique in rural areas of Guatemala and Benin. In both countries, we studied boys aged 6-12 y and their mothers. Subjects used lithium-labeled salt after all unlabeled salt was removed from their households. In Guatemala, 24-h urine samples for 9 mother-son pairs were collected at baseline and on days 7, 8, and 9 during the use of lithium-labeled salt. Total maternal salt intake averaged 5.2 +/- 1.7 g/d (mean +/- SD), of which 77 +/- 24% came from discretionary sources, whereas Guatemalan boys consumed 1.8 +/- 0.6 g salt/d, of which 72 +/- 12% came from discretionary sources. In Benin, urine collection from 13 mother-son pairs took place at baseline and on days 5 and 7. Beninese mothers had a total salt intake of 9.0 +/- 2.9 g/d and their sons had an intake of 5.7 +/- 2.8 g/d; discretionary salt contributed 52 +/- 14% and 50 +/- 13%, respectively, of total salt consumed. Therefore, fortification of household salt appears to be an appropriate method of controlling iodine deficiency in both countries, although fortification of other salt sources could be considered in Benin.