Salty Foods and Overweight Kids

Our daily sodium intake, in the developed countries, averages over 6000 milligrams of sodium per day. That's almost three times as much as the more reasonable recommendation of 2400 milligrams per day. With all that salt, there's also a well-documented link between salt intake and fluid intake in adults. (Certainly it makes sense: eat something salty, you get thirsty, you drink a beverage of some kind.)

We also know that sugary beverages, even though they contain calories, don't fill you up the way actual food does, and may actually lead you to eat more later than if you ate the same number of calories in food (Bite 11/07/07). Kids get a lot of their calories from those sweetened beverages. Researchers in the United Kingdom noted these two facts and asked themselves, "Could this high salt intake be linked to children's high sugared-drink intake - and therefore be a factor in children's overweight and obesity?" (Hypertension. 2008;51:629-634.)

To assess this possible link between salt intake and sugared-drink intake in children, the researchers made use of data from a large-scale, cross-sectional study (a study that is a "snapshot" of a single time period) of children's dietary and exercise habits during a normal week in the child's life. Over 1600 children ranging in age from 4 to 18 years kept a detailed dietary record (or their parents did) of everything they ate and drank in one week. They also kept track of their amount and types of exercise.

The results of the researcher's analyses are grouped by age and gender. Generally speaking, both boys and girls got about one-third of their total daily fluid intake from sugared soft drinks - girls slightly less than boys. When the scientists correlated this sugared soft drink consumption with the amount of salt in the children's diets, they found a "highly significant" connection between salt intake and sugared soft drink intake. So much, they found, that they predicted that cutting 1000 milligrams of salt per day from a child's diet would reduce a child's intake of sugared soft drinks by about 2 drinks per week (assuming the typical drink is about 250 grams of liquid), which is about 244 calories per week for each child. Cutting their salt intake in half could lead to an even larger reduction in the average number of calories each child consumes per week.

What this means for you

This doesn't necessarily mean that less salt will automatically lead to fewer calories - it simply means that less salt in a child's diet will mean that a child drinks less fluids overall, and therefore drinks less sugared soft drinks. Reducing the amount of salt in your family's diet is one way to help your child drink fewer soft drinks, but the best way is still to simply give them water instead.