High salt intake: Results of the Swiss Salt Study 2022

Adults in Switzerland consume almost 9 grams of salt daily. Com-pared with the recommended amount of 5 grams, average salt intake is around 75 per cent too high. In addition to salt intake, the study commissioned by the FSVO also investigated other parameters such as potassium intake, blood pressure and BMI.

Salt intake in Switzerland today – by sex, age group and region

Salt intake has decreased since the Salt Study 2010/11 was carried out, but it is still far too high. Women consume less salt than men, older people less than younger. There are no regional differences.

More about salt intake in Switzerland

Average salt intake in the adult population in Switzerland is 8.7 ± 3.6 g per day. Women consume an average of 7.4 g, men 9.9 g. The recorded minimum is 1.3 g daily, the maximum 26.5 g daily.
There is a difference between the sexes in all age groups. The oldest study participants, both men and women, have the lowest salt intake. The highest average intake is 10.9 g, recorded in men between 45 and 59 years of age.
There are no regional differences in salt intake between the three language regions.
Compared with the first Salt Study in 2010/11, salt intake in the population has decreased significantly by 0.4 g per day or 4.6% – from 9.1 g to 8.7 g. Consumption by women decreased from 7.8 g to 7.4 g, by men from 10.6 g to 9.9 g per day.

The proportion of individuals who consume less than the 5 g salt per day recommended by the World Health Organisation (WHO) is 14% ‒ 21% of women and 8% of men.
The proportion of individuals with daily salt intake below 5 g was also 14% in the first study.
In addition to sodium, chloride was measured in the urine samples. There is a very strong correlation between the two elements (Pearson’s r = 0.97).

Knowledge about salt and individual consumption habits

A large majority of the study participants are aware of the negative effects of salt on health. However, this knowledge is barely used to guide their consumption habits.

More about salt knowledge and consumption habits

The majority (82%) understand that salt has negative effects on health, with more women than men aware of this aspect (86% v. 78%).
Knowledge of the negative effects of salt varies by language region, with people in the French-speaking region of Switzerland being better informed (93%) than those in the Italian-speaking region (89%) and the German-speaking region (73%).

Hypertension is correctly identified by 82% of those surveyed as being directly related to salt intake. One in five people cannot name any disease directly related to salt intake.
There has been a slight improvement in knowledge of the health risks associated with salt since the first Salt Study was carried out in 2010/11. In addition to “hypertension”, “heart disease”, “heart attack” and “stroke” are more frequently mentioned as diseases directly related to salt.

Over 90% of participants state that they never or only rarely add salt to their food at the table, while 2% state that they always do. Only a good 4% of participants usually or always add salt to food outside the home. The number of people who never add salt to food at the table tends to rise with increasing age.
A good third of participants say that they are careful about salt consumption or limit it, with a greater proportion among older people. The 2010/11 study reported 63% of women and 54% of men in this category.
26% of participants estimate their own salt intake as low, 60% as moderate and 14% as high. Comparison with the level of salt actually excreted in urine shows that this assessment is correct for 36% of these people.

Compared with the first Salt Study, the proportion of women who never add salt to their food at the table at home has declined markedly, while the proportion of men who never add salt outside the home has increased.
The two options “Reduce/minimise the consumption of processed foods” and “Add little/no salt when cooking” are mentioned most commonly when participants are asked what they regularly do to avoid salt. “Buy low-salt alternatives” and “Avoid eating out” are mentioned the least often in comparison.

Potassium, the underestimated helper

Potassium plays an important role in regulating blood pressure. Increasing dietary potassium intake can considerably lower blood pressure. Women and young men consume less than the recommended amount of potassium.

More about potassium

As an antagonist of sodium, potassium plays an important role in regulating blood pressure in the body. Several cohort studies have shown that a high potassium intake is associated with lower blood pressure and a lower risk of cardiovascular disease. It has also been shown that increasing dietary potassium intake can significantly lower blood pressure in a dose-dependent manner. It is against this background that the present study also investigated potassium intake.

The WHO recommends a daily potassium intake of at least 3.5 g, which results in excretion of around 2.7 g potassium in the urine.
In the present study, an average of 2.7 ± 1.0 g/24h was measured in urine, 3.0 g/24h in men and 2.5 g/24h in women.
Women in all age groups and men in the 18–29 age group consume less potassium than the amount recommended by the WHO. Men in the 45–59 age group have the highest potassium intake at 3.2 g/24h.
Potassium intake also does not vary between the language regions.

The ratio of sodium to potassium (Na:K ratio) is another important indicator of possible health risks. At 2.1, women have a better Na:K ratio overall than men (2.4). According to the WHO, the ideal ratio is ≤ 1.0, the suboptimal ratio ≤ 2.0. Women’s lower potassium intake is balanced by their lower salt intake.

Overall, 96% of participants have a Na:K ratio above 1 and 54% have a ratio above 2. In both sexes, the youngest participants have the least favourable Na:K ratio, the oldest participants the best Na:K ratio. This could point to the quality of their diet, since foods such as vegetables, fruit, nuts, wholegrain products and pulses are important sources of potassium.

Salt and hypertension

Men’s blood pressure is significantly higher than women’s, participants from the German-speaking region of Switzerland have higher blood pressure than those from the French-speaking and Italian-speaking regions. There is a positive correlation between hypertension and salt intake.

More about salt and hypertension

Participants’ blood pressure was determined as the mean of eight measurements. Both systolic (SBP) and diastolic (DBP) were measured.
It was found that the mean SBP is significantly higher in men at 127 mmHg than in women at 116 mmHg. SBP increases with age in both sexes. The situation is similar for DBP, with men having an average value of 74 mmHg and women 71 mmHg. In women DBP increases continually with age, while men in the 45–59 age group have the highest value with an average of 78 mmHg. The maximum values measured were 169 mmHg (SBP) and 106 mmHg (DBP).
Analysed by region, participants in the German-speaking region of Switzerland have higher blood pressure (SBP and DBP) than participants in the other two regions.
The measured proportion of individuals with hypertension (≥ 140/90 mmHg or taking medication) is 24% in this study overall, 32% of men and 15% of women. The prevalence of hypertension has remained stable since the last Salt Study (26% in 2010/11), and there is once again a positive relationship between salt intake and SBP/DBP. Every additional gram of salt excreted has an effect on blood pressure.

Around 26% of participants had already been told by a healthcare professional before the study that their blood pressure was too high, 32% of men and 19% of women. Most of the people who had been warned are in the over-60 age group. 59% of these people take blood pressure medication.
Among the participants in whom hypertension had never been recorded previously (n=638) or who were not taking medication despite having been informed they had the condition (n=92), hypertension was measured in a total of 10% (34% of those who knew they had hypertension and 7% who did not know).
There is also a statistically positive relationship with BMI, since increasingly high SBP and DPB are measured for every additional kg/m2 of BMI.

Study participants’ anthropometric data

Compared with the 2010/11 Salt Study, there is no change in the proportion of overweight and obese individuals based on their BMI. The recorded waist and hip measurements show that, across all age groups, more women than men have a substantially increased disease risk.
There is a positive relationship between salt excretion and BMI. BMI is statistically higher for every additional gram of salt excreted. This effect is more pronounced in older participants.

More about study participants’ anthropometric data

Participants’ height, weight and waist and hip circumference were also measured at the study centre.
Men weigh 81.0 kg and are 177.5 cm tall on average. Women weigh 67.3 kg and are 165.4 cm tall on average.
At 25.7 kg/m2, men’s body-mass index (BMI) is significantly higher than that of women (24.6 kg/m2). Participants over 45 years of age have a higher BMI, particularly women and men in the 45–59 age group.
According to the WHO classification, 54% of participants have a normal weight (BMI < 25), 34% are overweight (≥ 25 BMI < 30) and 12% are obese (BMI ≥ 30).
Weight does not vary by region, but height does. Participants from the German-speaking region of Switzerland are taller on average and also have a lower BMI.

In the 2010/11 study, 32% of participants were overweight and 14% obese. The differences between this and the present study are not statistically significant.

Waist circumference (WC) was 95 cm for men and 85 cm for women. Waist circumference tends to increase with age. There are no differences between the language regions.

The WHO classification defines three categories of waist circumference for the purpose of assessing disease risk:
- Normal (women ≤ 80 cm, men ≤ 94 cm)
- Increased disease risk (women 80.1–88 cm, men 94.1–102 cm)
- Substantially increased disease risk (women > 88 cm, men > 102 cm)

In the present study, almost 25% of men and 24% of women have an increased disease risk. The disease risk is substantially increased in 23% of men and 34% of women.
The disease risk for both sexes according to waist circumference is lowest in the 18–29 age group. It is striking that, across all age groups, there is a greater proportion of women in the category with a substantially increased disease risk. The greatest proportion is 48% among women over 60.

There is no significant inter-sex difference for hip circumference (women 102.1 cm, men 103.7 cm).

The WHO also classifies the ratio between waist and hip circumference (waist-to-hip ratio, WHR) into two categories for the purpose of assessing disease risk:
- Normal (women ≤ 0.85, men ≤ 0.9)
- Substantially increased disease risk (women > 0.85, men > 0.9)

In the present study, 27% of men and 37% of women have a substantially increased disease risk on the basis of their WHR.
With respect to the WHR too, the youngest participants account for the largest proportion of people with no disease risk. And as with waist circumference, more women than men have a substantially increased disease risk in all age groups.

Background to the Salt Study

Objective and study design

Study objective
The objective of the study was to determine the daily salt intake of the adult population in Switzerland. Salt was measured in 24-hour urine.
Potassium (K), chloride (Cl), creatinine and iodine were measured in the urine samples in addition to sodium (Na).
A small quantity of the anonymised urine samples was frozen in addition and will provide samples for further analyses.
The participants were requested to fill out a web-based questionnaire on lifestyle, eating habits and physical activity.
The development of salt intake can now also be investigated in conjunction with the data from the first Salt Study in 2010/11.

Does salt excretion in 24-hour urine correspond to salt intake?
If good samples are obtained from 24-hour urine, sodium (Na) excretion corresponds to around 90% of Na intake. Na excretion is therefore taken to be equivalent to intake of Na or, after conversion, salt (NaCl). The same applies to potassium (K) excretion, where excretion is equivalent to around 70–75% of intake. Although it is lower than Na excretion, K excretion is also used to “approximate” K intake when calculating the Na:K ratio.

When was the study performed?
Participants were recruited between March 2022 and August 2023.

Who took part in the study?
A total of 863 people who received an invitation took part in this study. Participants were selected randomly by the Federal Statistical Office on the basis of population registers. Participation was voluntary for everyone, even though they had received an invitation.
Of this group, 858 people collected 24-hour urine to determine daily salt intake; 204 of them did it twice.
The overall participation rate in the study is around 8.7%; 10.4% of participants each come from the French- and Italian-speaking regions of Switzerland and 7.5% from the German-speaking region.
The study population comprises 52.1% men, 47.6% women and 0.2% “diverse”.
Four age groups were defined before the study started: 18–29, 30–44, 45–59 and over 60 years of age. The youngest age group accounted for the lowest number of participants at 14.6% compared with almost 30% for the other age groups. This number of youngest participants almost corresponds to the effective share of the population accounted for by this age group (16.3%). In contrast, the over-75s are under-represented in comparison with their effective number in the population.
In addition to sex and age group, sociodemographic data such as nationality, level of education, household type, civil status and household income were also recorded.

How the study was performed
The study covered the entire country and included the three major language regions. A total of four study centres were set up in Lausanne, Bern, Zurich and Bellinzona.
Study participants visited the study centre to which they had been assigned twice. During the first visit, each person’s blood pressure (systolic/SBP and diastolic/DBP value), weight, height and waist and hip circumference were measured. Participants were also given the material required and precise instructions for collecting 24-hour urine.
Participants returned the filled urine bottles to the study centre at the second visit. Each person’s blood pressure was then measured again. The online questionnaire could be completed individually or at a computer in the study centre.

Data protection
All personal data were anonymised. Evaluations are performed for entire groups at the population level (e.g. by sex or age group). It is therefore not possible to identify individuals.
Both this study and all other studies which use samples from the collected urine require approval by the National Ethics Committee.

Who performed the study?
The study was commissioned by the FSVO. The University Centre for Primary Care and Public Health (Unisanté, Lausanne) and Lausanne University Hospital (CHUV) performed the study in collaboration with Inselspital Bern, Zurich University Hospital and Bellinzona Regional Hospital.

More Information

Swiss survey on salt intake - Report of the 2022/2023 study

Swiss survey on salt intake - Report of the 2010/2011 study (PDF, 579 kB, 27.10.2011)

For general questions on the study, please contact the FSVO info desk:
Tel. +41 58 463 30 33 / info@blv.amin.ch

Media professionals please contact the FSVO media department:
Tel. +41 58 463 78 98 / media@blv.admin.ch