For most adults, the NHS recommends no more than 6 g of salt per day, approximately one level teaspoon and equivalent to about 2.4 g of sodium. WHO recommends less than 5 g of salt per day, equivalent to less than 2 g of sodium, for adults. These are population-level recommendations from different authorities rather than evidence that precisely 6 g is biologically necessary. The difference arises from the guideline frameworks used by the respective organisations. Both agree on the central principle that most adults should keep salt intake low because excessive sodium intake increases blood pressure and cardiovascular risk.
Salt is primarily sodium chloride, so sodium is the component most directly associated with the physiological effects of excessive salt consumption. Sodium is an essential electrolyte involved in maintaining extracellular fluid balance, nerve transmission and muscle function. The kidneys normally regulate sodium and water balance, but chronically high sodium intake can increase extracellular fluid volume and contribute to elevated blood pressure in susceptible people. Persistently high blood pressure increases the risk of cardiovascular disease, stroke and other complications. Salt is therefore essential in small amounts but harmful when intake is excessive.
Most dietary salt does not necessarily come from the salt shaker. In many diets, substantial sodium is already present in processed and packaged foods, including processed meats, bread, cheese, ready meals, savoury snacks, sauces, stock cubes and other convenience foods. Salt can also be added during cooking or at the table. This makes population salt reduction more complicated than simply telling people not to add salt to meals: food selection, food manufacturing, portion size and recipe composition all influence total sodium exposure.
A practical conversion is that 1 g of sodium corresponds to approximately 2.5 g of salt, while 1 g of salt contains about 0.4 g of sodium. This distinction matters because nutrition labels may provide sodium information rather than salt information, although UK packaged-food labels commonly report salt. The numerical values cannot be compared directly without conversion. For example, 2.4 g sodium corresponds to approximately 6 g salt, which explains the NHS adult limit. Understanding the distinction prevents the common mistake of treating sodium and salt as interchangeable quantities.
Reducing salt does not mean that a diet must be completely sodium-free. Sodium is physiologically necessary, and severe sodium restriction can be inappropriate in particular clinical circumstances. The objective for the general population is to avoid excessive intake. Practical measures include choosing lower-salt versions of processed foods, comparing nutrition labels, using herbs and spices instead of large quantities of salt, limiting processed meats and salty snacks, and being cautious with high-sodium sauces such as soy sauce and fish sauce. Potassium-rich foods can also be beneficial because potassium can mitigate some of sodium's adverse effects on blood pressure.
Children generally require less sodium than adults, with appropriate limits varying according to age and energy requirements. The adult 5-to-6 g salt figures should therefore not simply be applied to young children. Children can receive considerable sodium from processed foods, sauces, bread and snacks, so reducing exposure to heavily salted foods is useful. Infants and young children have particularly different nutritional requirements, meaning general adult dietary recommendations should not be applied indiscriminately to them.
A common misconception is that only visibly salty foods contain substantial salt. Bread, breakfast foods, cheese, sauces and processed meats can contribute meaningfully even when they do not taste extremely salty. Another misconception is that sea salt, Himalayan salt or other speciality salts are intrinsically healthier than ordinary table salt. Chemically, their principal sodium-containing component remains sodium chloride, and any trace minerals present do not eliminate the cardiovascular relevance of sodium. The important variable is total sodium or salt intake, not the marketing category of the salt.
The most practical interpretation is to keep total salt intake below the UK adult maximum of 6 g per day and recognise that WHO's broader public-health recommendation is below 5 g per day. The majority of sodium reduction usually comes from choosing less processed and less salty foods rather than merely removing the salt shaker.
A diet rich in vegetables, fruit, pulses, whole grains and minimally processed foods naturally makes it easier to control sodium intake, while highly processed foods can make the limit difficult to achieve. People with hypertension, kidney disease, heart failure or other conditions may receive more specific medical advice and should follow their clinician's recommendations where these differ from general guidance.
