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Health and medicine
Course: Health and medicine > Unit 10
Lesson 6: BMI and dietLow salt diet
Figure out the difference between "salt" and "sodium" and how much salt is recommended on a low sodium diet. Rishi is a pediatric infectious disease physician and works at Khan Academy. Created by Rishi Desai.
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- What would happen if you didn't have any salt in your diet? I realise that it's essential, but what would actually happen to your body if you didn't get any salt? How would it feel?(28 votes)
- The chemical reactions inside our bodies need sodium – one of the two elements that makes up salt (along with chloride). Without salt our bodies would cease to function. Muscles would stop working, nerves wouldn't carry messages and food would remain undigested.
Everyday our bodies lose salt - through sweat, urine and tears - and this must be replaced to keep our bodies working properly. So salt forms an essential part of a healthy balanced diet.
I hope this helps,
Allie(10 votes)
- Why do most table salts contain Iodine?(19 votes)
- The ingestion of iodide prevents iodine deficiency. Worldwide, iodine deficiency affects about two billion people and is the leading preventable cause of mental retardation.
[from the Wiki article Iodised salt]
Apparently global efforts to improve diet by including Iodine in table salt have been very effective. It's nice to reduce unwanted health issues with simple, inexpensive prevention.(21 votes)
- What does the chloride do to the body? also is it unhealthy?(11 votes)
- Sodium,when it is by itself, will combust when it comes into contact with oxygen. That is why you store straight up sodium in oil or in a vacum. Chlorine, by itself, emits a gas that is poisonous to humans and pretty much any living thing. But when sodium and chlorine are chemically bonded to form sodium chloride, they are safe to ingest and become necassary to many bodily funtions. Also, sodium chloride is really yummy on french fries. :D(21 votes)
- There a lot of salt substitutes on the market. I know they just a different salt that doesn't contain Sodium, but are there any health risks with using a comparable amount of this product to using salt?(18 votes)
- In general the non-sodium salts are safe for healthy people.
If you have kidney problems in particular, the replacement salts could be worse.(3 votes)
- At, how does he end up with 40%? Is it some kind of math? 2:55(3 votes)
- Yes. He took the atomic mass of Na and divided it by the molecular mass of NaCl. I checked his math, and it looks right. I hope this helps :)(5 votes)
- I saw this thing on a kosher salt bottle, that the salt contains iodine. what is iodine?(4 votes)
- Iodine is an element, with about 5 radioisotopes. Its atomic number is 53, and its symbol is I (uppercase). Its (only) one stable isotope is edible and helps your body, but some of the other radioisotopes are used in medical equipment.(3 votes)
- Why is having a lot of salt bad for you? Can't the body just excrete it out?(4 votes)
- Also if you consume too much salt and too little fluid to dissolve it, it is one of main factors for kidney stone creation.(4 votes)
- I've heard that potassium can neutralize sodium in the human body. Is it possible to consume a little more than one tea spoon of salt per day if I also eat enough of fresh vegetables and fruits?(2 votes)
- While potassium and sodium do work together in many ways, they don't offset one another in terms of your diet. So eating more of one would not make up eating a lot of the other. Too much or two little of either can cause problems.(2 votes)
- After reading some questions, I have a question. This video says not to have lots of salt in your diet. But, don't you need salt? So, can you eat salt but not too much right? Then can you put in a suggestion for a low salt diet, one that doesn't use a lot of salt, but just a good amount of salt that would keep you healthy and safe?(2 votes)
- You do need salt in your body.Yeah not the much not the little.Dont eat stuff the are bad for us /you. Every day you need 1500 m of salt(1 vote)
- Could you die without salt in your diet?(2 votes)
- yes you could die. It is necessary for you to have salt in your diet.(1 vote)
Video transcript
So, two words often
get thrown around and confused for one another. And I thought we would take
a few minutes to clarify the differences between
salts and sodium. And we know they're
related, but I wanted to get exactly
what the differences are, and how to make sense of all the
different numbers I hear around how much I'm supposed
to get every day. So, I always think for salts,
of my salt shaker at home. It sits right next
to my pepper shaker, and whenever I have dinner
I often reach for it. And sometimes I think,
am I eating too much of it or am I putting
on more than I should? And so I was thinking about
this in terms of a spoon. So if you have a spoon,
let's say a teaspoon of salt. And let's say I took
this teaspoon of salt-- here it is-- and I
weighed it on a scale. I would find that one teaspoon
of salt weighs about 6 grams. Let me write that here. So it's about six grams. And six grams is the
same as 6,000 milligrams. So that's the weight of
one teaspoon of salt. Now, the question comes up, how
much of that is from sodium? So, to answer that, we know that
sodium chloride, NaCl is salt. That is what salt is made of. And if I imagine there's
nothing in my salt shaker except for sodium chloride,
no ants have gotten in there, no other stuff besides
the sodium chloride, then I can assume that all
6,000 milligrams of salt is going to be either from the
sodium or from the chloride. OK. Now the Na, just be totally
clear, is the sodium part and the Cl is the chloride
part, that's what that means. And they actually, all atoms
have a certain atomic mass unit. So you can actually
weigh the atoms, and line them up by size, and
which is the largest in weight, and which is the
smallest in weight. And sodium weighs out
at about 23 units, and chloride is about 35 units. So this is chloride right here,
and this is sodium right here. And so if I was to
sum it up, I would get 23 plus 35 is 58 units. And units, just to say it again
or to write it out rather, is atomic mass units. So now that I have the
total atomic mass units, I can try to figure out what
proportion is from the sodium, and what proportion
is from the chloride. So for the first
part, the sodium, I can simply take the 23
units over the 58 unit total. The units cancel out. And that works out to about 40%. So that means that about
40% of the weight of salt is actually coming
from the sodium part, and the chloride part
is the rest of it. So I've got 35 units over 58
units, and that is about 60%. And again, the units
cancel out 60%. So I know that in
salt, 40% of the weight is coming from the sodium,
60% from the chloride. Got it. Now, I have to go
back to my teaspoon. In my teaspoon I had 6
grams, or 6,000 milligrams. So in that teaspoon, I can
just multiply by these numbers to figure out how much of the
weight comes from the sodium and how much comes
from the chloride. So the sodium gives
me 40% of 6,000, which, when you multiply
those two numbers you get 2,400
milligrams of sodium. And 60% times 6,000 is 3,600
milligrams of chloride. So now I know in
each teaspoon I have 2,400 milligrams of sodium. And now I've actually
looked and I've seen that there
are recommendations on how much sodium you
should get in your diet, if you're not having any
medical problems in general. So I'll call that a normal daily
salts amount, or normal amount. And this is regular, this would
be a regular amount of salts, and then there's
a low salt amount. So this would be
a low salt amount. So if you're on a
low-salt diet, we'll figure out how much salt
you're supposed to take in, or how much sodium you're
supposed to take in, and the same for regular. How much you should be taking
if you're on a regular diet. And I'm going to do it both
from a salt perspective and also from a
sodium perspective. So let's do the sodium
prospective first. So normal amount you
should get-- actually, let me write "per day." And let's do of sodium and
over here we'll do salt. So regular amount of sodium
you should get per day is about 2,300 milligrams. And on a low-salt
diet you should get about 1,500 milligrams. Now we know that 1 teaspoon
has 2,400 milligrams and 2,400 and 2,300, I think,
are pretty close. So in my conversion
I'm going to assume that that means I can have about
one teaspoon per day of salt. And on a low-salt diet,
you're recommended to have no more than about
1,500 milligrams of sodium. And if one teaspoon equals
2,400 milligrams of sodium, then 1,500 is about 2/3
of it, so that's about 2/3 of a teaspoon of salt. So when I look at a
teaspoon of salt now, I just remember that if this
is my teaspoon, that if I'm on a regular diet I can
basically take one of them each day, not each
meal but each day. And if I'm on a low-salt diet
I can only fill it up about 2/3 of the way, and I'd
have to stop there because that's the limit of
sodium that I'm recommended.