You need salt in your diet - probably about 3g a day - but it's extremely unlikely you're not getting enough. 'The hunter-gatherer Yanomamo tribes in the South American rainforests get by on less than half a gram a day and they are fighting fit,' says Graham MacGregor, professor of cardiovascular medicine at St George's Hospital, London. The current target in Britain is to reduce intake to 6g per person per day - though, as MacGregor says, that should just be a first step on a long road to a healthier national diet. Pre-school-age children should avoid salt as far as possible. Aged five or over, they still only need less than 4g a day.
Excessive salt is a major cause of strokes and heart attacks, the two major causes of death in this country. 'We could prevent 35,000 premature deaths a year,' claims MacGregor, 'if we reduced salt intake.' At the moment blood pressure rises with age; it was long thought that this was a purely natural, inevitable consequence of ageing. Now, says MacGregor, doctors realise it is less to do with nature than the fact that babies prefer mother's milk to microwaveable sausages and packets of salt-soaked crisps.
Eighty-five per cent of the salt we eat is hidden in processed or takeaway foods, rather than added at the table. So how much are you getting? It's not always easy to tell: many food packets talk about sodium content rather than salt content. To make sense of this, you need to know that every gram of sodium is equivalent to 2.5g of salt.
Some of the figures will make you gasp. A tin of supermarket anchovies contains 15g of salt per 100g. To put that in perspective, the fish in this can are six times saltier than the sea in which they once swam (the Atlantic contains around 2.5g of salt per 100g of water). And you thought the seawater you accidentally swallowed at the beach tasted salty.
Takeaway foods can contain surprises, too. The fast-growing Subway chain - there are currently more than 700 stores in the UK and Ireland, and the plan is for 2,000 by 2010 - offers a turkey breast and bacon melt that contains 5g of salt. In other words, a five-minute lunch snack can swallow up virtually your total daily salt allowance.
There is even salt lurking in foods that announce themselves as healthy and don't actually taste salty. A 30g serving of Kellogg's Corn Flakes eats up 9 per cent of your recommended daily maximum before you've even left the house, though to the company's credit, this figure is announced on the front of the packet. And just because something is 'light' does not mean it's not salty. Dairylea Light Slices ('a good source of calcium') may be lower in fat than standard Dairylea but they still contain 2.8g of salt per 100g.
So why do manufacturers pack in so much sodium chloride? MacGregor outlines the three most common reasons for packing salt into our foods. They are all rather depressing: 'Salt is a cheap way of making drab, tasteless ingredients acceptable to the palate.' This is also a self-fulfilling prophesy: some manufacturers fear that if they remove salt from their recipes, customers who have spent years being exposed to super-salty products will perceive their food as tasteless and swap to a rival brand.
The second reason salt is included in processed foods is because it can be used to bind water (the cheapest product of all) into meats. The third is arguably the most cynical of all: salt makes you thirsty - and many companies that sell you food are also keen to punt drinks in your direction. 'The parent company of Pepsi Cola also owns Frito-Lay, a huge snack company. If I were running a company that sold soft drinks, I think I'd be reluctant to see any reduction in salt consumption,' says MacGregor.
Peperami salami sausages
One stick contains 1g of salt, so if a child ate two sticks as an after-school snack, that would be half of their daily allowance.
Sodeb'O Just for me! Ham & Cheese pizza
The packaging for this pizza recommends it as 'a gourmet meal snack on its own or serve as a complete meal for a child', but there is salt in the base, the ham and the cheese. In total, the pizza contains 2.5g of salt - half the recommended daily limit for an eight year old.
Ye Olde Oak Ham
If a child eats half a 200g tin of this, they take in over half of their daily allowance. It's made from re-formed meat with added water.
Wall's Micro Sausages
Microwaveable sausages do not pretend to be haute cuisine. But if you eat four, you'll ingest 3.1g of salt - half of your daily allowance.
Kellogg's Corn Flakes
They don't taste salty but a 30g serving of Corn Flakes eats up 9% of your daily allowance.
Subway Turkey Breast and Bacon Melt Wrap
This lunchtime snack contains 5g of salt -more than 80 per cent of the total recommended daily limit. And the turkey breast is made from 're-formed meat' ...
Dry cured back bacon
'Dry cured with sea salt' boasts the packet -doesn't 'sea salt' sound so much healthier than mere salt? -and the ingredients list backs up the harsh truth: a 100g serving (about three rashers) consists of 3.6g of salt, more than half your daily limit.
Walkers Thai Sweet Chilli Sensations crisps
If you munched your way through half a big bag, that's 2.5g of salt, or a third of your daily allowance.
Schwartz Spaghetti Bolognaise Recipe Mix
This pack contains a shocking 5.5g of salt. If four people shared the resulting meal, they'll each have used up nearly a quarter of their recommended daily allowance. 'Sprinkle with cheese' recommends the packet -which means adding even more salt.
Dairylea Light Slices
You (or your children) may think this looks like a healthy product. 'Light' is reassuring, isn't it, as is the claim that this is 'a good source of calcium'. But 70% of a child's daily allowance would be swallowed up by 4 slices.
Kingsmill Head Start With Omega 3 bread
Three slices contain a sixth of the recommended daily intake of Omega 3, said to reduce the risk of heart disease. But they also contain 1.6g of salt.
Salt & vinegar Snack-a-Jacks
'Less than 10 per cent fat', says the pack in large letters. Much smaller letters on the back reveal that this 30g pack contains 1.5g of salt.
