Salt and Children
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The estimated amount of salt consumed by children
Although current salt intake in children is largely unknown, it is thought that children in many countries have a very high salt intake. For example, in the UK it is estimated that most children consume at least twice as much salt per day as necessary.
Methods used to estimate dietary salt intake in children, include; food diaries [1] , spot urinary sodium/creatinine ratio [2, 3] and overnight urinary sodium excretion [4-6] . However, it has been shown that none of these methods are reliable, and the only accurate method is to measure urinary sodium from complete 24-hour urine collection [7] .
There is only one small study in the UK that has measured 24-hour urinary sodium in school children [8] , to assess children's salt intake. The study was done in 1986 and showed that the average salt intake in children aged 4 - 6 years was 3.8 gram/day of salt, which if expressed for adults on weight basis, is equivalent to 15 to 20 grams/day of salt. This was at a time when consumption of processed foods by children was not high. Since then, salt intake in children in developed countries is likely to have increased due to the increasing consumption of processed, takeaway, restaurant and fast foods. Surveys in the USA showed that the proportion of foods that children consumed from restaurants and fast food outlets increased by nearly 300% between 1977 and 1996 [9] . Snack food consumption showed trends similar to those of fast food consumption. Restaurant foods, fast foods and snacks are generally very high in salt.
The most recent National Diet and Nutrition Survey (NDNS) in young people in Great Britain was carried out in 1997, and measured salt intake using 7-day dietary record in 856 boys and 845 girls [10] . The average salt intake, at the age of 4-6 years, was 5.2 gram/day for boys and 4.6 gram/day for girls. With increasing age, there was an increase in salt intake, and by the age of 15-18 years, salt intake was 8.2 and 5.7 gram/day for boys and girls respectively. However, these intakes considerably underestimated the actual amount of salt consumed by the children, as they did not include salt added in cooking or salt added at the table. Additionally, the 7-day dietary record is well-known to have a tendency to underestimate food intake [11-14] , which would lead to a further under-estimation of dietary salt intake. Since this survey was carried out salt intake in children and adolescents is likely to have increased further due to a greater consumption of highly salty foods since this survey was conducted. It is now likely that salt intake in children from the age of 4 onwards is the same as in adults, i.e. 9-10g a day.
A group of researchers in the Netherlands measured 24-hour urinary sodium excretion in 45, 5-10 year old children between 1993-1995 and 142, 5-10 year old children in 2003-2005. Their data show that salt intake has increased by more than 50% over the last 10 years [15].
In the UK , SACN (Scientific Advisory Committee on Nutrition), in 2003 set up target levels of salt intake for children [16] (Table 1). These recommendations are not ideal, and are far higher than what a child's maximum intake should be to meet their physiological requirements, but due to children's current high salt intake are based on what is feasible, and what is achievable.
Table 1. SACN recommendations for children
Age |
Target Average Salt Intake (g/day) |
0-6 months |
<1g/d |
7-12 months |
1 g/d |
1-3 years |
2 g/d |
4- 6 years |
3 g/d |
7-10 years |
5 g/d |
11-14 years |
6 g/d |