Weight Loss: How Much Salt Is Enough?

One of the questions that comes up at Thursday night weight loss group quite often is the question of how much salt we actually need, and how much is too much?

So what have I been able to find out?

Firstly, we don't need salt, as such. We need a small amount of sodium, most of which we habitually eat as salt (sodium chloride). About 90% of our sodium intake is in the form of salt, so for our purposes, watching our salt intake, is a good way to keep our sodium from getting out of hand.

The amount Australians eat, is far more than we actually need. Most of us are eating around 10 grams of salt a day.

The upper safe limit (according to the National Health and Medical Research Council - NHMRC) is 2300 milligrams (2.3 grams) of sodium per day. That equates to about 6 grams or 1 1/2 teaspoons of salt.  That is the maximum amount of sodium it is safe for an adult to eat (from all sources - not just what we add when cooking or at the table). Interestingly, this is the amount used for the % of Recommended Daily Intake used on boxes of cereal and other products.

The amount the NHMRC recommends as a target amount for people to eat is, not surprisingly, a long way below that upper limit.  It sets a target of 1600 milligrams (1.6 grams) per day for people who are older, overweight, have high blood pressure, or want to maintain a healthy blood pressure across the lifespan. I expect that people wanting to care for their blood pressure should include everyone.  That 1.6 grams of sodium equates to 4 grams of salt (a teaspoon full).

An "adequate intake" the minimum to give us all that we need is about 460 to 920 milligrams (0.4 to 0.9 grams) of sodium. That's about 1.15 to 2.3 grams of salt. (So unless you are eating less than half a teaspoon of salt from all sources each day, you are not in danger of having too little.)

So, all up, our salt from all sources should be no more than a teaspoonful in a day, or 1600mg of sodium, and having a little less than that will not hurt us.

Given that the average Australian eats more than twice that amount, we need to look at how to reduce our sodium intake.

Here are some tips:

1. Cook at home, instead of going out. Take-away food has lots of salt, and you only have to watch an episode of Master Chef to see how much chefs love salt. Cook without adding salt.
2. Use fresh ingredients wherever possible - virtually all packaged food products have some form of salt added. Fresh fruits and vegetables do contain sodium - but nowhere near as much as you will find in packaged foods.
3. When you must buy packaged food, choose foods that have less than 120mg of sodium per 100g of food. 
4. Use herbs and spices to add flavour to food, rather than fats and salts.
5. Remember the reason people like food that tastes of salt is just because of habit - habits can be changed.
6. Steam, grill, stir-fry, or microwave food. Don't boil food in water, because flavour is lost (along with some nutrition), and it is tempting to replace the lost flavour with salt.

And now, the big question: why bother?  What does eating too much salt do to our bodies? Excess salt is linked to:

1. High blood pressure
2. Kidney problems/ kidney stones
3. Oedema (swelling, fluid retention.)
4. Some Cancers
5. Osteoporosis (sodium encourages the body to excrete calcium)

There are also dangers from too little sodium, but it is very unlikely that people in Australia are going to suffer from this, because of the way salt is introduced into almost all our foods. (It's possible to die from both too much and too little sodium.)

References:

Better Health Channel: Salt http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Salt

Food Standards Australia: How Much Salt and Sodium are We Eating - More Information http://www.foodstandards.gov.au/scienceandeducation/factsheets/factsheets/howmuchsaltareweeating/howmuchsaltandsodium4551.cfm

Healthshare: How Much Sodium/Salt Should We Consume Per Day? http://www.healthshare.com.au/questions/42121-how-much-sodium-salt-should-we-consume-per-day

Mayo Clinic Nutrition and Eating:  Sodium: How to Tame Your Salt Habit Now http://www.mayoclinic.com/health/sodium/NU00284

Nutrition Australia: Salt and Hypertension http://www.nutritionaustralia.org/national/frequently-asked-questions/salt-and-hypertension