Most of the salt we eat in our diets is hidden in the likes of processed foods and ready-made meals such as sandwiches. And that's the rub with salt. No matter how much we cut back during cooking and at the table, we are still likely to exceed the recommended daily maximum of 6g because 85 per cent of our intake is buried in places we least expect it - in everything from our favourite sarnies, to biscuits, cereals, curries and crisps.

We don't need any additional salt in our diet and it only became popular when we got used to the taste after using it to preserve foods.

It may enhance flavour, but it also increases your odds of developing high blood pressure, heart disease and stroke - so much so that some experts now refer to it as a toxin.

Salt has been vying with smoking and obesity as the new Public Enemy No 1 since the Food Standards Agency launched a campaign to cut national consumption.

The organisation believes that half the British population are currently eating too much of it, and that cutting consumption by the equivalent of just half a teaspoonful a day could prevent as many as 70,000 strokes and heart attacks every year.

Most people in Britain are already well aware of the link between salt intake and high blood pressure, and the resulting damage to the circulation that leads to stroke and heart attack, and have started to cut back.

Salt sales are down from 55,000 tonnes a year in 1985 to less than 30,000 tonnes a year today, but the impact on the amount that we actually consume has been negligible because the drop pales into insignificance when compared with the 220,000 tonnes added every year to processed or pre-prepared foods such as sandwiches.

Reducing the amount of salt consumed at home is relatively easy. The palate quickly adjusts in much the same way that it does when you stop taking sugar in tea or coffee, and within four to six weeks most people no longer miss it. Unfortunately their efforts are rarely rewarded because the vast majority of their salt daily intake is likely to be hidden in processed foods and spotting this is very difficult.

And then there is the artery- clogging fat. You could be forgiven for thinking that a Marks & Spencer Vegetarian Cheese and Chutney Sandwich would be a healthy option for a quick bite when you are in a hurry. Yet, according to Which?, it contains more fat than a Big Mac, and more calories than you care to think about.

But fat and salt make foods palatable and tasty, and encourage you to buy them. Until we all adapt our palates to a low- salt, low-fat diet, don't expect the retailers to discontinue their most profitable lines without enormous amounts of pressure.

And until they do, and I wouldn't hold your breath, read all labels carefully and choose accordingly.

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