Experts at the Complutense University of Madrid assessed the sodium intake of 205 schoolchildren aged between seven and 11. The team collected urine samples over a 24-hour period.
The results, published in the European Journal of Nutrition, showed that the kids were consuming an average of 7.8 g of salt per day.
The World Health Organisation (WHO) recommends daily intake of salt should be no more than 4 g for those under 10 years old, and no more than 5 g for those over 10. In the research group, 84.5% of those under 10 and 66.7 % of those over 10, ate more than the WHO limits.
The researchers also found that the likelihood of excreting high levels of sodium in urine increased by 15.9% for each kilo/m2 of body mass index. “Overweight/obese subjects had higher urinary elimination of sodium than those of normal weight,” the authors noted.
This could be because high salt intake stimulates appetite and thirst, thus increasing overall energy intake, they suggested. However, this isn’t the only explanation.
Solutions to salt problems
High intake of salt is associated with early development of cardiovascular risk factors, such as high blood pressure, osteoporosis and obesity. Consumption of salty foods from childhood is also likely to continue into adulthood.
Encouraging children to eat less salt is therefore “a sound policy to reduce cardiovascular risk”, the authors explained. However, it is one that has been overlooked.
"Many parents aren't aware that their children, or they themselves, are eating too much salt,” said lead researcher Aránzazu Aparicio. “They think that reducing the amount added to food while cooking is sufficient to bring down intake.”
But in most industrialised countries, including Spain, only 20% to 25% of salt consumed comes from table salt. The majority is from processed foods, in which salt is “hidden”, Aparicio said.
Cured meats, bread, pizza, ready meals, stock cubes and sausages are among the products contributing the most salt to Spanish children’s diets, she said.
No European countries are reportedly on track to meet targets to cut salt intake by 30% by 2025.
"We clearly do have to control the salt we add to our meals when we eat,” Aparicio explained. “However, these results also show the need for the food industry to act to reduce the salt content of processed foods.”
Aparicio noted that reformulation of products with less salt can go unnoticed by consumers – in bread, salt content has been cut from 22g to 16.3g per kilo over a period of four years without complaint.
Source: European Journal of Nutrition
First published 19 October 2015, DOI 10.1007/s00394-015-1067-y
“Estimation of salt intake assessed by urinary excretion of sodium over 24 h in Spanish subjects aged 7–11 years.”
Authors: A. Aparicio et al.