The Link Between Too Much Sodium and Childhood Obesity

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Girl adds salt to french fries. Peter Dazeley/Photographer's Choice/Getty Images

While recent, conflicting studies about the optimal daily dose of sodium for adults may have had us all a bit confused, an even more recent study about children seems perfectly clear.  We are over-salting them.

Specifically, children and adolescents in the U.S. are averaging roughly 3300 mg of sodium daily.  This intake level is well above the current recommendation, and even above the higher threshold proposed in studies that have explored the perils of too little dietary sodium.

 

The links between dietary sodium and childhood obesity may not be immediately apparent, since sodium has no calories and does not contribute directly to weight gain. But the links are there, and quite important.

First, the principal hazard imposed by excess dietary sodium is high blood pressure.  The new CDC report on salt intake in children notes an association between the prevailing excess and a high and rising rate of hypertension in children.  Obesity, too, is a risk factor for hypertension, which in turn is a risk factor for both heart disease and stroke.  In the context of epidemic childhood obesity, more and more cardiac risk factors are seen at ever younger age.  The rate of stroke in children age 5-14 in the U.S. has risen 35% in recent years, apparently due to childhood obesity.

Since both obesity and sodium contribute to high blood pressure, the combination is apt to be worse than either alone.

  So excess dietary sodium compounds one of the important consequences of childhood obesity.

Second, we- and our children- tend to like the taste of salt.  Unlike sweet, salty may not necessarily be an innate taste preference, but at the very least, it is easily acquired.  Salt figures in the additions made to food, often rather clandestinely, to make them more palatable, and increase the eating we do before deciding we’ve had enough.

  This concept is famously reflected in the marketing slogan, “betcha’ can’t eat just one.”  The dedicated efforts of the food industry to engineer foods we can’t stop eating has been explored by investigative journalist Michael Moss, and by others before.

The net effect, therefore, of excess sodium in our children’s diets is an associated excess of calories.  An excess of calories is, of course, directly linked to obesity.

Third, and finally, the principal source of sodium in our children’s diets is not the salt shaker on the family’s kitchen table.  Rather, as implied above, it is salt added to processed food.  Nearly 80% of the salt in the typical American diet is processed into foods before ever a hand at home reaches for the salt shaker.  In the case of our children, nearly half the salt comes from a list of just ten commonly eaten foods, all of rather dubious nutritional quality.

So there is an indelible link between high intake of sodium, and high intake of junk food.  Junk food is, of course, directly linked to childhood obesity- and to adverse effects on health overall.

  Prior study has suggested that a third to a half of the calories in an American child’s diet may come from junk foods.  Salt is part of what make these foods so appealing, if not actually addictive.

This final consideration serves to highlight the appropriate remedy.  We need not fixate on sodium, or any very specific threshold of intake, to correct the prevailing excess in our children.  Rather, we may turn- as ever- to the remedy for all that undermines the quality of our diets: wholesome foods in sensible combinations.  If we- parents and children alike- eat more foods direct from nature, more foods prepared at home, and fewer highly processed foods, salt intake will go down.  That reduction in sodium is almost certainly a good thing for our children, and for us- but it is almost beside the point.  Replacing nutrient-dilute, energy-dense, and yes, salty junk foods – with nutrient-dense, energy dilute, natural foods confers a wide array of benefits related both to weight control, and overall health promotion. 

Un-pickling our children, in other words, can simply be a by-product and fringe benefit of eliminating “junk” as one of the major food groups in their diet.  There is no debate about the advantages of that.  There is simply the need for each of us, and all of us, to get it done.

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