New Zealanders need to reduce their salt consumption by at least half, public health expert and University of Auckland Emeritus Professor Robert Beaglehole says.
He issued his warning to draw attention to World Salt Awareness Week, which is presently under way.
Prof Beaglehole said New Zealanders were consuming an average of about 9g, or 1.5 teaspoons, of salt each day.
"The World Health Organisation recommends a daily intake of between 3g to 6g [6g is about one teaspoon], so ideally we should only be eating half as much as we do."
Too much salt in the diet led to high blood pressure, which increased the risk of stroke and heart disease. Salt intake was responsible for about one in three of new cases of high blood pressure and a high salt intake was also a cause of kidney disease and stomach cancer, and may also contribute to osteoporosis.
Prof Beaglehole said the necessary reduction in salt consumption would only be possible if food manufacturers gradually reduce the salt content of their products.
"About three-quarters of the salt is 'hidden' in processed or packaged foods, including bread and processed meats such as salami and bacon, smoked foods, marmite, food canned in brine, tomato sauces, chippies and instant noodles," he said.
"So there's a need for serious action by manufacturers of these products.
"Foods like bread, breakfast cereals, cheese, baked beans and crackers can contribute significantly to our daily salt intake because we tend to eat a lot of them."
Salt was often called sodium in the nutrition information panels on packaged food.
Prof Beaglehole is a former director of the World Health Organisation's department of chronic disease and health promotion, and is chair of The Lancet action group on non-communicable diseases.
World Salt Awareness Week 2011 has the theme of "Salt and Men's Health", chosen after British research showed men ate more salt than women and, on average, had higher blood pressure than women, particularly at a younger age.
NZPA