Sodium / Salt

lynn_glenmont wrote: »

Does the sodium listed on U.S. nutrition labels only include sodium from (table) salt (NaCl)? What if there are other compounds with sodium in the food, like baking soda (NaHCO3) or monosodium glutamate? Doesn't the label include that sodium as well?

The EU label seems weird to me, saying "Salt content is exclusively due to the presence of naturally occurring sodium," since you can have tons of naturally occurring sodium, but if there are no chloride ions, there's no salt. And it's sodium that's the concern (for those for whom it is a concern), not just sodium in salt, right?

The FDA says that those other sources of sodium are included in the Sodium number in the Nutrition Facts.

Some common food additives – like monosodium glutamate (MSG), sodium bicarbonate (baking soda), sodium nitrite, and sodium benzoate – also contain sodium and contribute (in lesser amounts) to the total amount of “sodium” listed on the Nutrition Facts Label.

As for that EU label, I just grabbed a random one I found on Google Images to use as a sample and I have no idea about how EU labeling is regulated.

kuranda10 wrote: »

The US and Australia have Sodium on the nutrional labels. As MFP is heavy on American members, where would the people be getting Salt numbers?

The United Kingdom, the OP is quite correct, could we not have a place to list salt please. It is a bind trying to convert it.

In Japan, our nutritional labels used to describe "sodium" (in-line with the US standard). However, a major study published in 2013 investigated if the people of Japan could understand the quantity of salt from nutritional labels. (PMID: 24173359 DOI: 10.1038/hr.2013.149 ) They found that only 13.3% of respondents could correctly determine the "salt equivalent" of sodium.

In other words, most people cannot make healthy choices based on the daily recommended salt intake, if "sodium" is written on the nutritional facts label. As a result, the nutritional labels in Japan have changed and now list "Salt Equivalent" instead of sodium (sometimes labels list both).

So this is probable rational as to why the UK and Europe (and now Japan) list "Salt" instead of "Sodium".

moestavern wrote: »

If you need to work out your intake from grams salt to milligrams of sodium, then follow this......

Grams of salt (in ur case as example 0.3)
Now divide that by 2.5 then multiply it by a 1000.

So 0.3 grams of salt contains 120mg of sodium.

To elaborate on this "2.5" number: in chemistry, this is the inverse of the molar mass ratio of sodium to sodium chloride. I can see this number has been used for simplicity, but here's an alternative which is more "intuitive":

Salt (sodium chloride) = 1 sodium atom + 1 chloride atom

Sodium atoms weigh less than chloride atoms, therefore (despite the 1:1 ratio), simply halving the mass of salt does NOT give the mass of sodium. In fact, the known mass ratio of sodium to sodium chloride is 22.99 : 58.44, which equates to 0.3934 grams of sodium per 1 gram of salt (22.99÷58.44=0.3934).

Since sodium is therefore 39.34% of salt, you can derive the sodium content from Japanese and European labels by multiplying the salt equivalent by 39.34%. Conversely, you can convert the sodium content of US labels into the salt equivalent by dividing by 39.34%.

But dividing is less "intuitive", so we can instead find the inverse and realise that 1÷0.3934=2.542. Rather than thinking "we know that sodium is 39.34% the mass of salt, let's reverse that", we can think "salt is 254.2% heavier than sodium".

This is where the "2.5" number comes from. However, if you're converting grams to milligrams, I would say 2.5 is insufficient. You should use 2.54 instead. To re-calculate the example mentioned:

300 milligrams Salt ÷ 2.54 = 118 mg Sodium (not 120 mg)

So, to summarise all of that, here are the general equations people will need:

Converting from US & Australian labels:
Salt Equivalent (g) = Sodium (mg) × 2.542 ÷ 1000

Converting from European & Japanese labels:
Sodium (mg) = Salt Equivalent (g) × 393.4
or
Sodium (mg) = Salt Equivalent (g) ÷ 2.542 × 1000

Disclosure: I have a science degree in biological chemistry.

Still an issue. I have started using the App and here in the UK food label shows SALT yet the App enters it as SODIUM. The food database I can see some entries as 1.1g of salt put in the app as 1.1mg of sodium. Completely incorrect so now I am closely monitoring this when scanning food with the bar code scanner.

All I know.. is whenever I used to log my food.. my sodium number was in red and way off the charts. I never understood why and I basically ignored all the breakdown recommendations and simply tried to hit my calorie limit. I never ate processed and salt ridden foods.so didn't get why the alarming huge number. I always thought it was off and an error on MFP programming.