In an observational study published in August 2022, more than half a million people completed a questionnaire about how often they salt their food before eating it. The questionnaire therefore only covered the extra salt added at the table, not the amount of salt used in cooking.

Among those who salted their food almost every time, the risk of premature death increased by 28%. Women aged 50 who used salt added afterwards suffered an average reduction in life expectancy of 1.5 years, compared with 2.3 years for men.

Salt is quite necessary, but it is easy to consume too much. People's average salt intake skirts the upper end of the healthy range, so it is not surprising that those who add extra salt to their food are already taking in more than they should.

Of course, no causal relationship can be established from similar observational studies. It is also possible that those who add salt to their food are doing so because they have become accustomed to higher salt intakes due to inadequate diets. Industrially processed foods and fast food are high in salt and have many other disadvantages.