I read or heard somewhere that average joe that eats processed foods gets only 25% of their sodium intake from salt added on the plate. the hidden sodium in processed foods is massive.
your proper potassium to sodium ratio for intake should be 2:1. often in processed foods the ratio is 1:5.
to have a look at the natural amounts in some whole foods, I ran a highest in potassium lowest in sodium search at nutritiondata.com and filtered to the vegetable category
http://nutritiondata.self.com/foods-011 ... xCount=187
Corn, sweet, yellow, cooked, boiled, drained, without salt....Potassium: 212mg Sodium: 0mg
Corn, sweet, yellow, cooked, boiled, drained, with salt........Potassium: 249mg Sodium: 253mg
Chard, swiss, cooked, boiled, drained, without salt............Potassium: 549mg Sodium: 179mg
(amounts jump to K 961mg and Na 313mg if you have a cup serving vs the 100mg serving specified in the search tool)
Chard, swiss, cooked, boiled, drained, with salt............Potassium: 549mg Sodium: 415mg
this food is listed as 'very high' in sodium (per the middle bottom of the 'food summary' section):
http://nutritiondata.self.com/facts/veg ... cts/2400/2
but the whole food actually looks like a great K:Na ratio, and then you just need to watch how much goes into the prep and serving side of things.
by way of comparison a cup serving of canned soup might have 600mg of sodium, easy.
according to the campbells web site their tomato soup has 960mg of sodium in a 1 cup serving. I can't find any data for potassium content.
a typical adult sodium intake might be 1500 - 2300 mg per day as per health Canada
http://www.hc-sc.gc.ca/fn-an/nutrition/ ... bl-eng.php