Joint Expert Consensus on the Sodium Reduction Policy in Taiwan: A Collaborative Declaration by the Taiwan Hypertension Society (THS), Taiwan Society of Cardiology (TSOC), International Life Sciences Institute (ILSI), and Nutrition Society of Taiwan (NST)

Abstract

Background

Excess sodium intake is a major modifiable risk factor for hypertension and other non-communicable diseases, including stroke, ischemic heart disease, and chronic kidney disease. Globally, average sodium intake remains more than twice the World Health Organization (WHO) recommended limit of 2 g/day, and Taiwan similarly faces a substantial sodium burden, with mean intake exceeding 3 g/day and a persistent policy implementation gap. Given the salt sensitivity of East Asian populations, these excess levels translate into disproportionately higher cardiovascular (CV) and broader health risks.

Objective

This consensus provides an evidence-based and culturally tailored roadmap to reduce sodium intake and increase potassium consumption in Taiwan, with the goal of achieving the WHO target of a 30% relative sodium reduction by 2030 and improving national CV health.

Methods

The consensus was developed through a comprehensive review of epidemiological studies, randomized trials, meta-analyses, and global burden models on sodium, potassium, and health outcomes. National intake patterns were assessed using Nutrition and Health Survey in Taiwan data from 2017-2020, while disease burden and cost estimates were informed by the Global Burden of Disease 2019 framework and local health statistics. An interdisciplinary expert panel adapted international evidence to the dietary context in Taiwan through iterative deliberation.

The Evidence

Robust evidence demonstrates a dose-dependent relationship between sodium intake, blood pressure, and CV risk, with each additional gram of sodium increasing CV disease risk by approximately 6%. Meta-analyses indicate that reducing sodium by 1 g/day lowers systolic blood pressure by about 3 mmHg in hypertensive individuals, and randomized trials such as the Salt Substitute and Stroke Study show that potassium-enriched salt can reduce stroke and major CV events. In Taiwan, sodium is derived mainly from salt, sauces, and processed foods, underscoring the need for both household- and industry-level interventions.

Scope of the Recommendation

The consensus recommends limiting sodium intake to < 2.3 g/day for adults and < 1.5 g/day for salt-sensitive or hypertensive individuals, while promoting potassium intake > 3.5 g/day from fruits, vegetables, legumes, or potassium-enriched salts (with caution in those at risk of hyperkalemia). Key policy actions include mandatory front-of-pack sodium labeling, food reformulation, institutional procurement standards, and sustained public education, supported by multi-sectoral collaboration across government, academia, industry, and civil society.

Table of Contents.

ABSTRACT……………………………………………………………………………………………………………………………………………………………………………….….	679
1. BACKGROUND AND PURPOSE…………………………………………………………………………………………………………………………………………………	679
1.1 Current dietary sodium pattern in Taiwan and worldwide………………………………………………………………………………………………	679
1.2 Health impact of excessive sodium intake………………………………………………………………………………………………………………………	680
1.3 Need for collaborative action………………………………………………………………………………………………………………………………………….	685
2. CURRENT STATUS OF SALT REDUCTION CAMPAIGNS WORLDWIDE………………………………………………………………………………………..	686
2.1 Salt reduction initiatives and their impact on heart health……………………………………………………………………………………………..	686
2.2 Overview of international guidelines………………………………………………………………………………………………………………………………	686
2.3 Evidence and recommendations for daily salt and potassium intake………………………………………………………………………………	687
3. STAKEHOLDER ROLES AND RESPONSIBILITIES…………………………………………………………………………………………………………………………	689
3.1. Academic institutions: research and evidence……………………………………………………………………………………………………………….	689
3.2. Medical associations: clinical guidelines…………………………………………………………………………………………………………………………	689
3.3. Industry partners: product reformulation………………………………………………………………………………………………………………………	690
3.4. Government agencies: policy framework………………………………………………………………………………………………………………………	690
4. ACTION PLAN AND GOALS………………………………………………………………………………………………………………………………………………………	691
4.1 Short-, medium-, and long-term goals…………………………………………………………………………………………………………………………….	691
4.2 Public education campaigns……………………………………………………………………………………………………………………………………………	691
4.3 Industry collaboration strategies…………………………………………………………………………………………………………………………………….	692
4.4 Healthcare provider engagement……………………………………………………………………………………………………………………………………	693
4.5 Monitoring, evaluation, and accountability…………………………………………………………………………………………………………………….	694
4.6 Economic impact assessment…………………………………………………………………………………………………………………………………………	697
4.7 Implementation challenges, risks, and mitigation strategies in Taiwan…………………………………………………………………………..	697
4.8 Safe adoption of potassium-enriched salt substitutes: risk stratification and clinical considerations………………………………	698
5. CONSENSUS STATEMENT………………………………………………………………………………………………………………………………………………………..	698
ACKNOWLEDGMENT………………………………………………………………………………………………………………………………………………………………….	699
DECLARATION OF CONFLICT OF INTEREST………………………………………………………………………………………………………………………………….	700
AUTHOR CONTRIBUTIONS………………………………………………………………………………………………………………………………………………………….	700
REFERENCES……………………………………………………………………………………………………………………………………………………………………………….	700

Abbreviations

ACC/AHA, American College of Cardiology/American Heart Association

AI, Adequate intake

BP, blood pressure

CDRR, chronic disease risk reduction

CI, confidence interval

CKD, chronic kidney disease

CV, cardiovascular

CVD, cardiovascular disease

DASH, Dietary Approaches to Stop Hypertension

DRI(s), Dietary Reference Intake(s)

EMR, electronic medical record

ESC, European Society of Cardiology

FOPL, front-of-pack labeling

GBD, Global Burden of Disease

HPA, Health Promotion Administration

HR, hazard ratio

IHD, ischemic heart disease

ILSI, International Life Sciences Institute

K/Na, Potassium-to-sodium

KAP, knowledge, attitudes, and practices

KPI(s), key performance indicator(s)

LSSS, low-sodium salt substitute(s)

M&E, monitoring and evaluation

MOE, Ministry of Education

MOHW, Ministry of Health and Welfare

Na, sodium

Na/K, sodium-to-potassium

NaCl, sodium chloride

NASEM, National Academies of Sciences, Engineering, and Medicine

NAHSIT, Nutrition and Health Survey in Taiwan

NCD(s), non-communicable disease(s)

NHI, National Health Insurance

NHIRD, National Health Insurance Research Database

NHIS, National Health Interview Survey

NHRI, National Health Research Institutes

NST, Nutrition Society of Taiwan

NTD, New Taiwan dollar

QA, quality assurance

QALY(s), quality-adjusted life year(s)

RAAS, renin–angiotensin–aldosterone system

RDI, recommended dietary intake

RR, rate ratio

SBP, systolic blood pressure

SSaSS, Salt Substitute and Stroke Study

SWA, sales-weighted averages

TFDA, Taiwan Food and Drug Administration

THS, Taiwan Hypertension Society

TOHP, Trials of Hypertension Prevention

TSOC, Taiwan Society of Cardiology

UI(s), uncertainty interval(s)

UK, United Kingdom

USD, United States dollars

WHO, World Health Organization

YLLs, years of life lost

24h-U, 24-hour urinary sodium excretion

1. BACKGROUND AND PURPOSE

To ensure clarity and consistency in this consensus document, the definitions and conversion principles for sodium and salt are as follows: (1) The term "salt" denotes sodium chloride (NaCl), while "sodium" specifically indicates its cation (Na); (2) According to the molecular weight ratio of Na to NaCl, 1 g of sodium chloride comprises approximately 0.393 g (393 mg) of sodium. A rounded conversion is used in this document for clarity and public communication: 1 g of salt is approximately 400 mg of sodium; for low-sodium salts (salt substitutes), sodium content is determined based on the proportion of NaCl in the mixture.

1.1 Current dietary sodium pattern in Taiwan and worldwide

According to the World Health Organization (WHO), the global mean daily sodium intake is 4.31 g (~10.78 g salt),¹ which is more than twice the WHO recommended daily intake for adults (2 g). The Nutrition and Health Survey in Taiwan (NAHSIT) has collected dietary information using the 24-hour recall method, including foods, condiments, commercial brands, and recipes, from homes and vendors since 1993. Sodium consumption levels are estimated using 24-hour dietary recall; however, this method may slightly underestimate intake because it often fails to capture discretionary salt added during home cooking or at the table, and relies on the participants’ memory of portion sizes and ingredients.

Among Taiwanese adults aged 19-64, daily sodium intake marginally declined from 3.7 g in 1993-1996 to 3.453 g in 2017-2020. Despite this trend, 2017-2020 survey data showed that consumption across all adult age groups consistently exceeded both WHO (2 g/day) and Taiwanese Dietary Reference Intake (DRI) (2.3 g/day) recommendations.² Intake typically peaked in the 19-44 age group (4.140 g for males; 3.196 g for females) before declining to its lowest levels in those aged 75 and above (please see Figure 1 for details), correlating with overall energy intake patterns.³

Figure 1.

Mean sodium intake relative to the recommended level (2400 mg/day) among Taiwanese adults aged ≥ 19 years (2017-2020) (cited from Nutrition and Health Survey in Taiwan [NAHSIT] 2017-2020 survey data³).

Natural foods contributed minimally to total sodium (7.0-9.4%), while the majority was derived from salt and sauces added during cooking (42.5-56.2%). Processed foods accounted for the remaining 34.7-50.5%, with wheat-based staples such as noodles and bread representing approximately half of this intake. While younger adults consumed significantly higher levels of sodium from processed items such as fast foods and sausages, salted vegetables were a primary contributor among older demographics (19 years and above). In addition to the contribution of wheat products in almost all age groups, the major contributing processed foods in younger age groups (19-44 years) were fast food (e.g. fried chicken), sausages, hot dogs, and various kinds of meat or fish balls, whereas those in older age groups (65 years and above) were processed/pickled foods such as salted vegetables.

These sodium consumption patterns highlight the importance of selecting prudent cooking and seasoning methods, minimizing the intake of processed foods, and encouraging product reformulation. Therefore, it is crucial to develop age-specific strategies for reducing sodium consumption.

Throughout this consensus, sodium (Na) is used as the primary scientific term for intake targets, biomarker monitoring, and epidemiological reporting, whereas ‘salt’ is used when referring to culinary practices, food composition, or public communication, to maintain both scientific precision and practical relevance.

1.2 Health impact of excessive sodium intake

A substantial body of evidence demonstrates a causal and dose-dependent relationship between dietary sodium intake, blood pressure (BP), and cardiovascular (CV)–renal outcomes. Population-based observational studies consistently show that higher sodium intake is associated with elevated systolic and diastolic BP across age groups and ethnicities, with particularly pronounced effects among salt-sensitive individuals, including older adults and East Asian populations.^4-7

Meta-analyses of randomized controlled trials indicate that reducing sodium intake lowers BP in both hypertensive and normotensive individuals, with greater absolute reductions observed among those with pre-existing hypertension. On average, a reduction of approximately 1 g/day of sodium is associated with a decrease in systolic BP of around 2-3 mmHg, supporting the clinical relevance of even modest population-wide reductions.^8-11

Elevated sodium intake contributes to cardiovascular disease (CVD) risk not only by increasing BP but also through adverse effects on vascular function, left ventricular hypertrophy, and arterial stiffness. Longitudinal cohort studies have linked high sodium consumption to increased risks of stroke, ischemic heart disease (IHD), and heart failure, independent of other risk factors. These associations are further supported by global burden of disease analyses attributing a significant proportion of CVD mortality to excessive sodium intake.^12-17

Regarding renal health, excessive sodium intake exacerbates glomerular hypertension and proteinuria, accelerating chronic kidney disease (CKD) progression, particularly in individuals with pre-existing renal impairment or diabetes. Experimental and clinical studies suggest that high sodium intake can blunt the renoprotective effects of renin–angiotensin–aldosterone system (RAAS) inhibitors, underscoring the importance of sodium reduction as an adjunct to pharmacologic therapy in CKD management.^18-20

Empirical evidence regarding the health risks of CV and non-CV diseases associated with excessive sodium intake is summarized in Table 1.

Table 1. Cardiovascular and non-cardiovascular health risks associated with excessive sodium intake.

Domain	Health outcome	Evidence summary	Representative references
Cardiovascular	Elevated blood pressure	Excessive sodium intake increases extracellular volume and vascular resistance, resulting in dose-dependent blood pressure elevation.	6, 14, 21, 17, 22
	Cardiovascular disease events	High sodium intake is associated with increased risks of cardiovascular events and mortality; large cohort and pooled analyses demonstrate linear or J-shaped associations depending on intake level and assessment method.	6, 13, 23, 16
	Stroke	Excess sodium intake contributes substantially to global stroke burden; sodium reduction lowers stroke incidence, particularly when combined with potassium-enriched salt substitutes.	13, 24, 17
	Heart failure progression	Sodium-induced volume overload and neurohormonal activation may exacerbate heart failure outcomes; excessive restriction may also activate the RAAS in vulnerable populations.	25, 26
Renal	Chronic kidney disease progression	High sodium intake impairs renal hemodynamics, increases glomerular pressure, and accelerates CKD progression independent of blood pressure effects.	20
	Albuminuria	Modest dietary salt reduction significantly lowers urinary albumin excretion in individuals with diabetes or impaired glucose tolerance.	18
	Nephrolithiasis	Excess sodium intake increases urinary calcium excretion, contributing to kidney stone formation.	27, 22
Gastrointestinal	Gastric cancer	High dietary salt intake increases gastric cancer risk, particularly in Asian populations; mechanisms include mucosal damage and enhanced Helicobacter pylori colonization.	28, 29
Skeletal	Osteoporosis	Sodium-induced calciuria is associated with reduced bone mineral density and increased osteoporosis risk, especially in post-menopausal women.	27, 22
Immune/inflammatory	Immune dysregulation	High sodium intake alters gut microbiota and modulates immune cell differentiation toward a pro-inflammatory phenotype.	30
Neurological/cognitive	Cognitive impairment and dementia	High sodium intake is associated with cognitive decline and increased dementia risk, potentially mediated through vascular dysfunction and immune dysregulation.	31-33
Metabolic	Metabolic syndrome and insulin resistance	Excess sodium intake is associated with increased waist circumference, insulin resistance, and metabolic syndrome components, beyond hemodynamic effects.	34, 35

CKD, chronic kidney disease; RAAS, renin–angiotensin–aldosterone system.

At the population level, intervention studies have demonstrated that replacing regular salt with potassium-enriched salt substitutes lowers BP and reduces the incidence of stroke and major CV events without increasing serious adverse outcomes in the general population. These findings provide strong support for integrating sodium reduction with potassium optimization as a dual strategy for CV and renal protection.^24,36-38

1.2.1 Role of potassium in sodium metabolism

Potassium is the principal intracellular cation, whereas sodium is the predominant extracellular cation; their balance is central to fluid homeostasis and BP regulation. Prospective cohort data indicate that a higher potassium-to-sodium (K/Na) ratio is inversely associated with BP, suggesting that potassium status should be considered jointly with sodium intake in hypertension prevention.³⁹

Regarding the primary mechanisms of action, two principal pathways explain the BP-lowering effects of potassium. First, potassium enhances urinary sodium excretion and reduces tubular sodium reabsorption, leading to a reduction in intravascular volume and BP, particularly in the short term.⁴⁰ Second, higher plasma potassium promotes endothelium-dependent vasodilation by stimulating Na⁺/K⁺-ATPase and potassium channels in vascular smooth muscle, thereby reducing peripheral vascular resistance.⁴⁰

The interaction with sodium intake is an important consideration when evaluating potassium-related interventions, as the balance between sodium and potassium plays a critical role in BP regulation. The BP-lowering effect of potassium is more pronounced in individuals with high sodium intake and in those who are salt sensitive.⁴ Consequently, dietary sodium and potassium should be evaluated together rather than in isolation when designing strategies for BP control.³⁹

Long-term CV implications should also be considered, as sustained imbalances in sodium and potassium intake are associated with increased risks of hypertension, stroke, and other CV outcomes. A higher dietary K/Na ratio is more strongly associated with lower BP and reduced CVD risk than either nutrient alone.¹⁷ Meta-analyses of prospective studies have shown that higher potassium intake is associated with lower stroke risk and reduced incidence of coronary heart disease and total CVD.⁴¹

Evidence from salt-substitute trials further supports this concept, demonstrating that replacing sodium chloride with potassium-enriched alternatives can lead to significant reductions in BP and CV events. Although few trials have simultaneously reduced sodium and increased potassium, large-scale potassium-enriched salt substitution studies provide robust evidence of clinical benefit. In a Taiwanese retirement-home study, replacing regular salt with a 50% potassium chloride–containing substitute reduced CVD mortality by ~40% over 31 months and lowered medical expenditure.³⁶ In the Salt Substitute and Stroke Study (SSaSS) in rural China, a 25% potassium chloride–containing salt substitute significantly reduced BP, stroke, major CVD events, and all-cause mortality without increasing serious adverse outcomes in the general population.³⁶ A recent meta-analysis of randomized trials confirmed consistent BP reductions with potassium-enriched salt substitutes.²⁴

Taken together, these findings support an integrated strategy of moderate sodium reduction combined with increased dietary potassium (or potassium-enriched salt) as an effective and scalable approach for CV and renal protection.

A simplified diagram illustrating the above mechanisms is shown in Figure 2. The figure illustrates the complementary and opposing physiological effects of sodium and potassium intake on renal sodium handling, RAAS activity, vascular function, and CV risk, with an emphasis on the sodium-to-potassium (Na/K) ratio.

Figure 2.

Pathophysiological mechanisms linking sodium–potassium imbalance, renal regulation, and cardiovascular risk (adapted from Adrogué et al., 2007⁴²). RAAS, Renin–angiotensin–aldosterone system.

1.2.2 The impact of high sodium intake on population health and healthcare expenditure

Diets high in sodium are the leading dietary risk factor for death and disease globally, accounting for > 1.8 million deaths and 45 million disability-adjusted life years from 1990 to 2017.^15,43 In addition, diets high in sodium induce high BP, which was responsible for > 10 million deaths and 235,000 disability-adjusted life years from 1990 to 2019.⁴⁴ High sodium intake and high BP increase the risk of CV and kidney diseases.^15,43 More than 50% of CVD deaths from ischemic heart disease (IHD) and stroke and 60% of kidney disease deaths have been attributed to high BP, with a further 7-10% of deaths due to high sodium intake.^15,43 The large-scale Nutrition and Chronic Diseases Expert Group (NutriCoDE) study assessed sodium intake among individuals in 66 countries, representing a population of 3.83 billion, and evaluated its global impact on CV mortality using data from 107 randomized interventions. The modeling study estimated that 1.65 million CV deaths were attributable to sodium consumption exceeding 2 g/day in 2010.¹³

The link between high sodium intake and health outcomes is well established. However, to understand the magnitude of the effect of sodium intake on health in Taiwan, it is vital to assess the attributable disease burden and associated healthcare costs.

To assess the effect of sodium intake on disease burden in Taiwan, we used the comparative risk assessment framework from the Global Burden of Disease Study 2019 (Global burden of disease, GBD 2019).⁴⁵ A full review of the methods has been described previously.⁴⁶ In brief, data on the strength of the relationship between sodium intake and each disease were obtained from GBD 2019.⁴⁷ We used overnight urine sodium concentration from the NAHSIT 2017-2020 and converted it to 24-hour sodium intake under the assumption that sodium excretion remains constant.^48-50 We then added a 7.2% adjustment factor to account for sodium lost via non-urine channels (e.g., sweat).⁵¹ For CV and renal disease outcomes, we modeled the mediating effect of sodium on systolic BP to determine the attributable burden, while for gastric cancer, we modeled the direct effect of sodium.⁵² Cause-specific death data were obtained from the National Death Registry, and years of life lost (YLLs), which capture premature death, were calculated from the residual life expectancy according to the GBD 2019 standard life tables.⁵³ Healthcare expenditure was estimated using the National Health Insurance Research Database (NHIRD). Uncertainty intervals (UIs) were calculated using a 1000-draw Monte Carlo simulation.⁵⁴

Among Taiwanese adults (> 20 years), 5,216 [95% UI: 3,464-5,933] deaths were attributed to high sodium intake in 2019.⁴⁶ The largest number of attributable deaths was from IHD (1,609 [95% UI: 1,214-1,865]), followed by stroke (including ischemic and hemorrhagic strokes) (1,552 [95% UI: 1,117-1,863]), and hypertensive heart disease (846 [95% UI: 220-1,013]) (Figure 3A). Among deaths from the 10 diseases included in this study, 10.43% [95% UI: 6.93%-11.86%] were attributable to high sodium intake. The attributable mortality for individual diseases ranged from 3.95% [95% UI: 2.59%-4.97%] for peripheral artery disease to 22.14% [95% UI: 16.49%-27.16%] for gastric cancer.

Figure 3.

Population burden associated with a high sodium diet, Taiwan 2019. NTD, New Taiwan Dollars. Stroke includes ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. Error bars represent 95% uncertainty interval of the total burden.

The relative ranking of attributable YLLs was similar, reaching 96,943 [95% UI: 68,790-107,961] attributable YLLs in 2019; IHD (32,886 [95% UI: 26,629-37,140] YLLs), stroke (23,570 [95% UI: 18,067-27,304] YLLs), and hypertensive heart disease (19,096 [95% UI: 8,016-21,885] YLLs) contributed the most sodium-related YLLs. Attributable burden was greater in men than in women (72,461 [95% UI: 51,871-80,423] YLLs vs. 24,483 [95% UI: 16,919-27,613] YLLs), which reflects both a higher disease rate and larger proportion of attributable YLLs (15.46% [95% UI: 11.07%-17.16%] vs. 9.08% [95% UI: 6.28%-10.24%] in women), suggesting that differences in sodium intake may contribute to the sex disparity in premature mortality due to these diseases.

High sodium intake is also a major contributor to healthcare costs. Attributable healthcare expenditure (including inpatient, outpatient, and pharmaceutical costs) was 14.01 [95% UI: 10.33-16.25] billion New Taiwan Dollars (NTD) in 2019, with the highest expenditure on CKD (6.44 [95% UI: 4.77-7.73] billion NTD), followed by stroke (2.88 [95% UI: 2.20-3.35] billion NTD), and IHD (2.71 [95% UI: 2.21-3.05] billion NTD). Attributable costs were concentrated in the 65+ and 40-64 age groups (49.78% [95% UI: 47.12%-50.77%] and 48.12% [95% UI: 47.08%-50.86%], respectively) (Figure 3B). In 2019, 11.35% [95% UI: 8.37%-13.17%] of the total healthcare expenditure for sodium-associated diseases and 2.12% [1.56%-2.46%] of the total National Health Insurance (NHI) expenditure were attributable to high sodium intake.⁵⁵

The high costs associated with high sodium intake are influenced by the high prevalence of excessive sodium intake and the high cost of treatment for sodium-associated diseases. IHD, urinary diseases (including CKD), and stroke are among the most expensive chronic diseases to treat annually.⁵⁶

Methods to reduce the sodium-associated population burden and costs should be considered, particularly because previous research suggests that targeting sodium may be among the most cost-effective methods to reduce the burden of non-communicable diseases (NCDs).⁵⁷ Strategies proposed in other countries include public sodium reduction campaigns, the promotion of potassium-enriched salt substitutes, mandatory sodium reformulation targets for food manufacturers, and front-of-label warnings on processed food goods. Numerous modeling studies and reviews have been conducted to test the cost-effectiveness of these and other interventions, with results suggesting significant cost savings and healthy life-years gained across several Asian countries and globally.^46,57-60

In Japan, four sodium reduction strategies comprising a national media campaign, traffic-light labeling system for processed foods, voluntary reformulation of processed foods by the food industry, and mandatory reformulation of processed foods with legislation, were shown to be highly cost-effective. The net benefit ranged from 140 million United States dollars (USD) annually from the national media campaign, to 2,015 million USD annually from mandatory reformulation.⁵⁹ Similarly, a study from Indonesia assessed the effect of the gradual uptake of a low-sodium high-potassium salt substitute and manufacturing reformulation targets, and estimated 42.8 USD per capita savings over the cohort’s lifetime, even after accounting for program costs and increased healthcare expenditure from other causes due to longer life expectancy.⁶⁰

Evidence from other countries therefore suggests that interventions to reduce sodium intake are cost-effective solutions to prevent disease, extend healthy life, and lower healthcare expenditure. Sodium contributes significantly to the disease burden in Taiwan, with high mortality and premature death burden as well as substantial healthcare costs. Future studies should consider examining the impact and cost-effectiveness of various sodium reduction and substitution strategies in Taiwan with the goal of identifying feasible and cost-effective strategies to reduce the sodium-related disease burden.

1.3 Need for collaborative action

Reducing sodium intake at the population level is a complex challenge that cannot be overcome by government action alone. As emphasized in the WHO Global Report on Sodium Intake Reduction (2023),⁶¹ effective sodium reduction policies entail multi-sectoral engagement involving government agencies, the food industry, academic researchers, healthcare professionals, civil society, and the media. This is particularly relevant in Taiwan, where previous governmental policies have shown limited effects in lowering sodium intake, which remains above 3 g/day on average, far exceeding both the WHO and national recommended limits.

Collaboration is necessary to address the different aspects of this issue. For example, public health authorities must lead regulatory policy development, such as mandatory front-of-pack sodium labeling and procurement standards for schools and hospitals. Academic institutions can contribute by providing surveillance data, evaluating policy impacts, and guiding evidence-based interventions. In addition, the food industry can play a crucial role in product reformulation and innovation, such as replacing sodium chloride with potassium-enriched substitutes, which have been endorsed by recent clinical reviews as feasible and effective for reducing CV events.⁶²

Healthcare providers are key influencers of individual behavior and should be actively involved in sodium education during clinical encounters. Civil society organizations and the media can promote public awareness campaigns and low-sodium eating environments.

Experience from countries such as the United Kingdom (UK), Finland, and Japan suggests that coordinated and sustained efforts across all sectors can lead to significant reductions in sodium intake and related health outcomes. To attain substantial progress toward the WHO’s 30% sodium reduction goal by 2030, Taiwan requires an established multi-stakeholder collaborative platform, and this prompted the development of the "Joint Expert Consensus on the Sodium Reduction Policy in Taiwan". This statement is based on expert counseling from all relevant stakeholders, including the Taiwan Hypertension Society (THS), Taiwan Society of Cardiology (TSOC), International Life Sciences Institute (ILSI) Taiwan, and the Nutrition Society of Taiwan (NST). After numerous expert consensus meetings and a comprehensive review of the evidence, we developed this joint expert consensus to provide recommendations for future sodium reduction initiatives in Taiwan.

2. CURRENT STATUS OF SALT REDUCTION CAMPAIGNS WORLDWIDE

2.1 Salt reduction initiatives and their impact on heart health

The WHO presently recommends a maximum daily salt consumption of 5 g, which is approximately equivalent to 2 g of sodium.⁶³ However, it is estimated that the vast majority of adults worldwide (99.2%) exceed the recommended level. Globally, approximately 1.28 billion adults aged 30-79 years have hypertension.⁴³ In 2019, the number of deaths attributed to excessive sodium intake reached three million worldwide.¹⁵ Salt intake reduction is one of the most cost-effective strategies for controlling BP and preventing CVDs.⁶¹ Limiting sodium intake to less than 2 g/day (equivalent to approximately 5 g/day of salt) for adults can help to reduce BP and the risk of CVDs. Moreover, for every US$1 invested in expanding sodium reduction initiatives, there is an estimated return of at least US$12.⁶¹

Currently, approximately 96 countries have established national salt-reduction strategies, most of which are multi-faceted and often include voluntary or mandatory food reformulation targets, public awareness efforts, front-of-pack labeling systems, and fiscal policies. Among these 96 countries, 89 (93%) have adopted a combined approach involving two or more implementation strategies. Specifically, 74 countries (77%) have adopted multi-component strategies. The most common measures include food reformulation in collaboration with the food industry (68/96 countries, 71%), consumer education campaigns (50/96, 52%), front-of-pack nutrition labeling (48/96, 50%), and salt taxation (5/96, 5%). These initiatives often span various settings such as schools, workplaces, hospitals, and government offices. Ongoing efforts are underway to monitor compliance and support the enforcement of these strategies.⁶³

2.2 Overview of international guidelines

Excessive sodium intake is a major contributor to elevated BP and CVD, prompting health authorities worldwide to advocate for dietary sodium reduction. Numerous international and national guidelines emphasize sodium restriction as the primary strategy for the prevention of hypertension and NCDs.^61,62,64

The WHO has long recognized the global health impact of high sodium intake. The 2025 WHO guidelines on lower-sodium salt substitutes recommend reducing population-level sodium intake by 30%, aiming for a maximum of 2 g of sodium per day (equivalent to 5 g of salt).⁶⁵ The WHO also strongly supports the use of potassium-enriched salt substitutes as an effective public health intervention, especially in settings with high sodium and low potassium consumption.⁶⁵ In accordance with the recommendations of the WHO, the National Academies of Sciences, Engineering, and Medicine (NASEM) also recommend a DRI for sodium of approximately 1.5 g/day, and for chronic disease risk reduction (CDRR) intake should be no more than 2.3 g/day.⁶⁴

The Dietary Guidelines for Americans and American College of Cardiology/American Heart Association (ACC/AHA) recommend limiting sodium intake to no more than 2.3 g/day, with a more stringent target of 1.5 g/day for individuals with hypertension, diabetes, or CKD.⁶⁶ The recent 2025 ACC/AHA hypertension guidelines⁶⁷ reinforce this recommendation, citing robust evidence from clinical trials such as the Dietary Approaches to Stop Hypertension (DASH)-Sodium⁶⁸ and the Trials of Hypertension Prevention (TOHP).⁶⁹

The 2024 European Society of Cardiology (ESC) hypertension guidelines align closely with the WHO recommendations, advocating dietary sodium intake close to 2 g/day (or ~5 g of salt), particularly in patients with hypertension or high CVD risk.⁷⁰ These guidelines highlight the synergistic benefit of combining sodium restriction with other lifestyle interventions such as the DASH or Mediterranean diet.

In Taiwan, the 2024 guidelines from the TSOC for the primary prevention of atherosclerotic CVD also endorse sodium restriction (2.4 g/day) as a core component of lifestyle interventions,⁷¹ a recommendation considerably lower than its hypertension guidelines (2-4 g/day) published in 2022.⁷² These recommendations have been integrated with broader CV risk management strategies, including lipid control and BP monitoring. Specific attention has been placed on older populations. The 2024 guidelines for elderly hypertension management highlight elevated sodium sensitivity in older adults and recommend low-sodium salt or potassium supplementation as effective adjuncts for BP control.⁷³

Despite a growing consensus, the implementation of sodium reduction policies remains inconsistent. A 2025 WHO review found that while potassium-enriched salt substitutes are supported by robust evidence for reducing BP and CVD risk,⁶⁵ their use is inconsistently recommended across clinical guidelines for hypertension and CKD.^74,62 Although most guidelines, in accordance with the WHO guidelines, recommend restricting sodium intake to < 2 g/day, the range is quite wide (from < 1.5 to < 6 g/day),⁶² probably reflecting some inconsistent observations of the J-curve phenomenon in epidemiological sodium studies.^6,14,23,75 as well as concerns over potential RAAS activation and lipid dysregulation with sodium restriction.^19,25,76,77

International guidelines have consistently highlighted potassium as a critical nutrient for CV health, particularly in the context of BP management. The 2017 and 2025 ACC/AHA guidelines on hypertension emphasize the importance of adequate potassium intake, especially from dietary sources such as fruits and vegetables, as a non-pharmacological intervention to reduce BP.^66,67 The 2019 NASEM report on DRIs reaffirmed the role of potassium in CV protection and established updated adequate intake (AI) levels of 3.4 g/day for adult men and 2.6 g/day for adult women.⁶⁴ However, the Committee concluded that the evidence was insufficient to set a CDRR intake or tolerable upper intake level, underscoring the need for further research.⁶⁴ The WHO’s 2025 guidelines on lower-sodium salt substitutes (LSSS) provide a focused recommendation for replacing conventional salts with potassium-enriched formulations. The guidelines support LSSS as safe and effective for BP reduction and CVD prevention in the general population, while emphasizing caution in individuals with advanced kidney disease, those on potassium-sparing diuretics, or those already using potassium supplements.⁶⁵ The 2024-2025 updates to hypertension management guidelines, including the ACC/AHA⁶⁷ and ESC guidelines,⁷⁰ recommend that daily potassium intake can be up to 3.5-5 g/ day, with an increasingly recognized potassium-rich salt substitute as a practical adjunct to dietary modification to lower the urinary Na/K ratio. Despite these endorsements, clinical practice guidelines remain somewhat inconsistent in their strength of recommendation and in defining safe upper limits, reflecting the gaps in evidence and the risk of hyperkalemia in vulnerable groups.⁶²

2.3 Evidence and recommendations for daily salt and potassium intake

2.3.1 Sodium intake

Globally, sodium intake significantly exceeds recommended levels. The average daily sodium consumption is estimated to be 4.3 g/day (equivalent to approximately 11 g of salt), which is more than double the WHO recommended maximum of 2.0 g/day.⁶⁵ The 2019 U.S. NASEM report defined a CDRR of 2.3 g/day for adults.⁶⁴ Numerous studies have shown a direct dose-dependent association between sodium intake and elevated BP.^{6,10,11,19,23} The DASH-Sodium trial demonstrated that reducing sodium intake from 3.3 g/day to 1.5 g/day in the context of a healthy diet significantly lowered systolic blood pressure (SBP), particularly in hypertensive individuals.⁶⁸ More recent prospective cohort studies have confirmed the CV risks associated with excess sodium. In a pooled analysis of six cohorts using multiple 24-hour urinary sodium collections, each 1 g/ day increase in sodium was associated with an 18% higher risk of CVD events (hazard ratio [HR], 1.18; 95% confidence interval [CI], 1.08-1.29).¹⁷ Similarly, the 2021 SSaSS in rural China demonstrated that even partial replacement of sodium chloride with potassium chloride (a salt substitute) significantly reduced the risks of stroke (rate ratio [RR], 0.86), major CV events (RR, 0.87), and all-cause mortality (RR, 0.88).²⁴ Although sodium reduction has been shown to decrease BP, evidence regarding its effect on overall CV events or all-cause mortality is not as robust as that for BP reduction. The J-curve phenomenon of sodium reduction in CV events or death remains under debate.^21,25,75,78 Although reverse causality and inaccurate or biased estimation from spot urine have been proposed to explain the J-curve phenomenon, there is evidence showing that sodium restriction induces sympathetic and RAAS activation as well as lipid dysregulation,^19,25,76,77 which are unambiguous risk factors for CV events and death, particularly in patients with comorbid conditions such as heart failure,²⁶ diabetes,⁷⁹ hyponatremia, and postural hypotension. This concern is also supported by an old study showing that Yanomamo Indians with "no salt" culture had low BP and extreme RAAS activation, but a short average life expectancy.⁷⁶ Consequently, we conclude that sodium intake should be limited to less than 2.3 g per day for the general population. Existing evidence supports extreme sodium reduction (e.g., < 1.5 g/day),²⁵ which may be appropriate for sodium-sensitive hypertensive patients such as older adults with hypertension.⁷³

2.3.2 Potassium intake

Potassium plays crucial roles in vascular function, cellular homeostasis, and neuromuscular control. The WHO recommends a potassium intake of at least 90 mmol/ day (3.5 g/day),⁶² whereas AI levels in NASEM 2019 are defined as 3.4 g/day for adult men and 2.6 g/day for women.⁶⁴ However, the average global intake falls short of these values, with many populations consuming less than 2 g/day.⁸⁰ Higher potassium intake is significantly associated with lower BP and diminished CV risk at the same levels of sodium intake, as reported in the DASH trial.⁶⁸ A 2015 meta-analysis of 15 randomized controlled trials revealed that potassium supplementation significantly reduced systolic and diastolic BP by 4.7 mmHg and 3.5 mmHg, respectively, in normotensive and hypertensive individuals not on medications. This effect was more pronounced among hypertensive subjects (SBP reduction of 6.8 mmHg).⁸¹ Importantly, this benefit was closely linked to absolute potassium intake and a lower Na/K ratio.⁸¹ Long-term outcomes of this study support these findings. In a 30-year follow-up study in a Japanese cohort, 24-hour urinary potassium excretion was inversely associated with all-cause mortality. Participants in the highest quartile of potassium excretion had a 38% lower mortality risk compared to those in the lowest quartile (HR, 0.62; 95% CI, 0.48-0.79; p < 0.001), while sodium excretion showed no significant association.⁷⁸ In addition, a pooled cohort analysis from Harvard revealed that each 1 g/day increase in urinary potassium excretion was associated with an 18% lower risk of CVD events (HR, 0.82; 95% CI, 0.72-0.94).¹⁷

2.3.3 Sodium-to-potassium ratio

Emerging evidence suggests that the Na/K ratio may be a better predictive marker for BP⁸¹ and CV risk⁷⁸ than sodium or potassium intake alone. In the Harvard pooled cohort study, the Na/K ratio was significantly associated with CVD events, with the highest quartile having a 62% increased risk compared to the lowest quartile (HR, 1.62; 95% CI, 1.25-2.10). This underscores the importance of addressing both factors concurrently rather than focusing on sodium reduction alone.¹⁷ Decreasing the Na/K ratio via potassium supplementation to < 1.5 may be a particularly useful strategy for those who have difficulty in reducing their sodium intake to < 2.3 g/day.

2.3.4 LSSS: a pragmatic intervention

Replacing regular salt (100% NaCl) with potassium-enriched substitutes (typically 75% NaCl and 25% KCl) has gained attention as an effective and scalable intervention.⁶⁵ An early Taiwanese report³⁶ and meta-analysis³⁷ of studies using potassium-enriched salt substitutes showed that this strategy is useful for treating CVDs and hypertension. Moreover, the 2021 SSaSS trial in rural China provided robust evidence that such substitutes reduced the risks of stroke, CV events, and all-cause mortality without significantly increasing the risk of hyperkalemia.²⁴ A 2023 follow-up study quantified the actual intake of potassium-enriched salt, showing that replacing just 72% of regular salt with a substitute led to an average 0.8 g/day increase in urinary potassium excretion and a modest 0.35 g/day reduction in sodium excretion, still yielding substantial health benefits.⁸⁰ However, caution should be exercised while attempting to generalize this strategy to the general population for potential hyperkalemia, particularly for those taking potassium-increasing drugs or those with CKD, diabetes, a history of heart failure, or low body mass index.³⁷ Although the WHO 2025 guidelines on LSSS indicate limited evidence regarding LSSS in children and pregnant women,⁶⁵ this consensus focuses exclusively on adults (≥ 19 years), and therefore does not address use in these populations.

3. STAKEHOLDER ROLES AND RESPONSIBILITIES

3.1 Academic institutions: research and evidence

The NAHSIT 2013-2016² classified sources of sodium in the diet into three categories: natural foods, salt or seasonings added during eating or cooking, and processed or seasoned foods. Sodium is not derived from salt in natural foods. For adults aged ≥ 19 years, the NAHSIT 2013-2016 reported that the main source of dietary sodium was salt or seasonings added during eating or cooking (51%), followed by processed or seasoned foods (41%), and natural foods (only approximately 8%). Nearly 90% of the dietary sodium intake of Taiwanese was derived from processed, packaged, and prepared foods or salts and seasonings added during eating or cooking. Based on successive nutrition surveys, the top six sources of sodium intake for adults aged 19-64 years have remained consistent in the following order: salt, soy sauce, other seasonings, wheat and flour products, pork and pork products, and steamed buns and dumplings.

Dining out is prevalent worldwide.⁸² A survey conducted in the United States showed that ≥ 50% of adults eat out more than three-times per week, while 35% of adults eat fast food meals at least two times every week.⁸³ According to the results of the 2017-2020 National Nutrition Survey, owing to school- and work-related lifestyles, the proportion of individuals aged 19-64 years eating out is high in Taiwan, with 38.2-35.6% and 37.6-23.2% of adults aged 19-44 and 45-64 years reporting eating out "7 to less than 14 times per week" and "14 to less than 21 times per week", respectively. The frequ-ency of eating out has been reported to decline with age.²

Restaurant dishes have higher sodium content than homemade foods,⁸⁴ and eating out is associated with higher sodium intake.^84,85 Ma et al. (2014) reported that few individuals in the United States are aware of the health risks associated with high sodium intake and generally lack knowledge about the salt content in packaged foods.⁸⁶ This gap can be addressed via education-focused interventions, including community awareness programs, school-based education, and media campaigns aimed at promoting salt reduction.⁸⁷ Translational research is essential for promoting sodium reduction initiatives. Such research should encompass surveys on the sodium levels in processed or prepared foods, evaluations of salt consumption within specific populations, and intervention studies aimed at decreasing sodium intake. Furthermore, research on the knowledge, attitudes, and practices (KAP) related to salt reduction and their correlations with hypertension and CVDs is crucial for informing evidence-based public health initiatives.

3.2 Medical associations: clinical guidelines

The current guidelines of the ACC and AHA for the prevention, detection, evaluation, and management of hypertension recommend six non-pharmacological interventions: reducing alcohol consumption, lowering salt intake, increasing potassium intake, engaging in regular physical activity, achieving weight loss, and following a heart-healthy diet.⁶⁶ Similarly, the International Society of Hypertension emphasizes the importance of lifestyle interventions and recommends their use alongside anti-hypertensive medications for optimal BP control.⁸⁸

The 2022 Guidelines of the THS and the TSOC state that sodium intake should be restricted to 2-4 g/day (5-10 g of salt per day) for better BP control and lower CV risk.⁷²

Despite continuous efforts to prevent and manage hypertension, the global number of patients with hypertension doubled between 1990 and 2019.⁴³ The management and prevention of hypertension often involve nutritional and dietary modifications, which are considered effective non-pharmacological strategies.⁹⁰ Due to accumulating evidence of the health risks associated with excessive salt consumption, the Japanese Society of Hypertension revised its guidelines in 2004, lowering the salt intake target to < 6 g per day per adult. Subsequent updates published in 2009, 2014, and 2019 have maintained this recommendation.⁹¹

Deepak et al. conducted a community-based crossover intervention study to determine the effects of dietary sodium intake on BP, and the results suggested that BP reduction achieved via dietary sodium reduction was similar to that of a commonly prescribed first-line anti-hypertensive drug.⁹² It is a generally accepted concept that reducing sodium intake reduces BP, and previous studies have shown that a modest reduction in sodium intake of 1 g/day led to reductions in SBP of 3.1 mmHg in hypertensive and 1.6 mmHg in normotensive subjects.^9,10 In addition, combining the DASH diet with low-sodium intake has been shown to lead to a more significant reduction in BP than following either alone.⁹² The TOHP are notable for their long-term interventions with follow-up periods ranging from 18 to 48 months, achieving a net reduction in sodium excretion of 0.76 to 1.0 g/day. One study reported a 30% reduction in CV events among participants in the intervention group.⁹³

3.3 Industry partners: product reformulation

High sodium intake is not only a result of individual choices, but is largely shaped by the broader food system, where factors such as affordability, availability, and industry-driven product formulations restrict access to healthier options. Policies to reduce the sodium added during food processing and in meals prepared outside the home by 10% can be implemented and repeated at yearly intervals without detection by most consumers.^8,9,61

Sixty-two countries, representing approximately one-third of all countries worldwide, have instituted national food reformulation strategies designed to diminish the sodium content of packaged foods, utilizing either voluntary or mandatory targets and mechanisms involved in the food industry.⁴⁴ Industry strategies to lower the sodium content include elimination (reducing or removing added salt), modification (altering the physical structure of salt crystals), substitution (replacing salt with alternative minerals), and compensation (reducing salt while enhancing flavor with natural flavors and enhancers).⁹⁴

Salt substitution has attracted considerable attention as a key strategy for salt reduction. Recent meta-analyses of the CVD prevention effects of salt substitution have been conducted.^38,95 One meta-analysis examined the long-term (≥ 6 months) effects of salt substitution on CV outcomes from 16 randomized controlled trials, and found that salt substitution reduced the risks of all-cause mortality (RR, 0.88; 95% CI, 0.82-0.93) and CV mortality (RR, 0.83; 95% CI, 0.73-0.95).⁹⁵ Salt substitution represents a promising and scalable non-pharmacological intervention that could reduce mortality, especially among populations such as those adhering to an East Asian diet or those at high risk of CVD.⁹⁰

3.4 Government agencies: policy framework

In general, salt reduction policies aim to promote, educate, and collaborate with stakeholders to reduce sodium intake. The development, implementation, monitoring, and evaluation of sodium reduction policies should be government-led and safeguarded against possible conflicts of interest.⁶¹ Governments play a central role in setting national targets, enacting supportive regulations, and ensuring transparency and accountability in policy processes.

A WHO evaluation across 183 countries identified that implementing a government-led "soft regulation" policy to reduce national sodium consumption by 10% over a 10-year period would be highly cost-effective in nearly every country worldwide.⁵⁷ To assist countries in prioritizing interventions, the WHO has identified a set of evidence-based intervention strategies to tackle NCDs. There are four optimal strategies for sodium reduction and they are expected to accelerate results in terms of lives saved, healthy years of life gained, cases of disease prevention, and costs avoided.⁹⁶

• Reformulate food products to contain less sodium, and set target levels for the amount of sodium in foods and meals.

• Establish a supportive environment in public institutions such as hospitals, schools, workplaces, and nursing homes to provide lower sodium options.

• Implement front-of-pack labeling; and

• Apply behavior change communication and media campaigns.

A systematic review conducted by Cappuccio et al. (2015) indicated that some successful policies included comprehensiveness, which involved health education, population monitoring, and reformulation to decrease salt concentration in processed foods.⁹⁷ Population-based salt reduction policies are rapid, equitable, powerful, and cost-effective.

Front-of-pack labeling helps consumers make quick and informed decisions about the sodium content of packaged foods. Simple formats such as traffic light labels and high-sodium warnings have been shown to reduce sodium purchases and encourage reformulations.^61,98 Taiwan can expand its current labeling system to include interpretive symbols that highlight the risks of sodium.

From 2001 to 2011, the average sodium intake in the UK decreased by 15% from approximately 3.8 to 3.2 g/day (equivalent to 9.5 to 8.1 g/day of salt). This achievement was closely linked to the national salt reduction strategy launched in 2003. The success of this policy was mainly attributed to three key strategies: enhancing nutrition labeling, launching public awareness campaigns, and implementing a government-led salt reduction model that set low-salt targets for more than 85 different food categories that had to be achieved by food manufacturers within a specified time frame.^99,100 In 2012, South Korea launched its National Plan to Reduce Sodium Intake, which comprised the following main components: (1) a consumer education campaign aimed at shifting dietary habits, (2) increased access to low-sodium foods in schools and workplaces, (3) greater availability of low-sodium options in restaurants, (4) voluntary reformulation of processed foods to reduce sodium levels, and (5) creation of low-sodium recipes for home cooking. In addition, the plan included monitoring and evaluation (M&E) efforts to track sodium intake and dietary sources. By 2014, adult sodium consumption had decreased by 23.7% compared to the 2010 levels, achieving the original target six years ahead of schedule. The progress made by South Korea can be emulated by other countries, particularly Asian countries such as Taiwan, which have similar food sources and consumption profiles.

4. ACTION PLAN AND GOALS

4.1 Short-, medium-, and long-term goals

Implementing a national sodium reduction strategy in Taiwan requires an explicit and flexible plan that balances measurable targets with local dietary habits and the capacity of the health system. International experience shows that coordinated multisectoral approaches are the most effective in achieving population-wide reductions. For example, the WHO SHAKE framework encompasses surveillance, industry engagement, public awareness, and knowledge translation, and it has guided successful sodium reduction efforts in several countries.¹⁰¹ The WHO has called for all Member States to implement sodium reduction policies and set a global target of a 30% relative reduction in population sodium intake by 2025, with many countries now considering extending this target to 2030 owing to slow global progress.⁶¹

4.2 Public education campaigns

Sodium intake plays a crucial role in BP regulation. Although medical interventions are available for CVDs, our understanding of the beneficial effects of sodium intake control remains inadequate. This is a significant challenge as well as an excellent opportunity for the government to develop public education campaigns to empower consumers to make healthier choices and reduce the risk of CVDs. Endorsement from medical professionals will foster the implementation of salt reduction communication in clinical practice and community health promotion programs.

Reducing salt intake from high-sodium food categories and seasonings is one of the most effective strategies for lowering sodium intake. In line with this approach, the WHO urges that action should be taken to formulate foods to contain less salt; set targets for the amount of sodium in foods and meals; establish public food procurement policies to limit salt- or sodium-rich foods in public institutions such as hospitals, schools, workplaces and nursing homes; provide front-of-package labeling that enables consumers to select low-sodium products; and implement behavior change communication and media campaigns to reduce salt/sodium consumption.

Therefore, nationwide awareness campaigns should be launched to promote public health education. A toolkit with information and resources can help distribute relevant dietary tips and provide guidance on sodium reduction to different generations or target groups. The recent NAHSIT indicated that young people should avoid overeating processed or seasoned foods. At the same time, middle-aged and elderly individuals should pay attention to reducing the amount of salt and seasoning added to their food or when cooking. Mass media campaigns are among the most effective tools for improving public knowledge about sodium-related health risks. The WHO identified these campaigns as one of the "best buys" for non-communicable disease (NCD) prevention.⁹⁶ In Taiwan, similar efforts should target specific high-risk populations, such as working-age adults, emphasizing how salt contributes to hypertension and CVD.

School-based interventions can support a healthier food environment;^61,98 however, this consensus does not address behavioral change among individuals < 19 years, focusing instead on adult populations. Integrating sodium reduction education into the national health curriculum can help establish early awareness and healthy taste preferences. In addition, community programs led by local health centers can provide cooking demonstrations, meal-planning workshops, and salt reduction challenges.

Changes in the dining environment, such as removing salt shakers from tables or setting default low-sodium options, have proven successful in changing consumption patterns without restricting choices.^61,98 These changes can be especially effective in institutional settings such as schools and hospital cafeterias, where the government has procurement control.

In terms of civil organizations, ILSI Taiwan has initiated a public–private collaboration platform to promote salt reduction campaigns, combining low-sodium food innovation and renovation with public education programs. These initiatives also highlight the importance of gradually adapting dietary preferences to lighter tastes in order to support healthier eating habits. Subsequent efforts have been further promoted with the involvement of the TSOC and THS and disseminated via healthcare lectures targeting both medical professionals and the general public.

Future research should create integrated media communication campaigns for consumer education. Attempts should be made to make consumers aware of the sodium level in their food via nutrition facts information and front-of-pack labeling, leading to changes in consumer behavior to improve sodium intake management and CVD reduction.

4.3 Industry collaboration strategies

Effective sodium reduction in food supply necessitates close and sustained collaboration with the food industry. In Taiwan, where processed foods, sauces, and condiments contribute significantly to dietary sodium intake, strategic alliances with manufacturers, retailers, and ingredient suppliers are crucial. The following are evidence-based strategies to facilitate effective industrial engagement. Educational initiatives targeting food industry workers, restaurant chefs, and retail staff can promote a cultural shift toward lower-sodium product offerings. Public recognition or certification of "low-sodium restaurants" or "sodium-smart products" can encourage broader societal support.⁹⁸

Key strategy components

1. Setting explicit, measurable reformulation targets

Governments should establish both voluntary and mandatory sodium content targets across key food categories using benchmarks such as the WHO global sodium benchmarks.⁴⁴ A 2022 review indicated that 62 countries have implemented reformulation strategies, with 43 establishing specific targets for packaged foods.⁴⁴ Targets should be explicit (mg sodium per 100 g), category-specific, and include upper bounds and means. Phase reductions over time can enable the industry to adjust its production, flavor profiles, and consumer acceptance.

2. Voluntary agreements supplemented by regulatory mechanisms

Voluntary engagement is often a helpful starting point, but it may need to be reinforced with regulations if progress stalls. The US Food and Drug Administration’s Guidance for Industry provides voluntary short-term goals for numerous food categories, striking a balance between feasibility and public health.¹⁰² Similarly, voluntary targets set in the Healthy Food Partnership in Australia are in the early stages of adoption; however, progress is modest, especially among large manufacturers.¹⁰³

3. Transparent monitoring, reporting, and incentives

Transparent systems should be established to monitor the sodium content in processed foods. The industry should report its progress and compliance assessments should be made publicly available. Recognition, certification, or fiscal incentives (e.g., tax incentives) for companies that achieve reformulation benchmarks can motivate action. Evaluations from countries using regulatory or hybrid strategies have shown higher compliance and greater sodium reduction.⁴⁴

4. Consumer–demand alignment and branding

Industry collaborations must also include marketing and consumer communication. As consumer preferences shift toward lower-sodium products, companies leading reformulation efforts can gain a market advantage. Labels, "low-sodium" seals, and consumer education campaigns can assist this process. Partnerships with retail chains to promote reformulated products can help to create scale.

Taiwan-specific implementation considerations

1. Prioritize the reformulation of sauces, condiments, and conventionally processed foods because of their significant impact on sodium consumption in Taiwan.

2. If voluntary progress is insufficient, voluntary reformulation initiatives should be combined with policy levers, such as mandatory targets for certain categories.

3. Ensuring the alignment of targets with local food composition data and consumer taste thresholds to avoid adverse taste perceptions.

By implementing a structured, evidence-informed industry collaboration strategy, Taiwan can significantly reduce sodium content in its food supply, foster innovation in seasoning and product development, and support healthier dietary patterns. Monitoring, incentives, and transparent collaboration are crucial for ensuring industry accountability and sustained progress.

4.4 Healthcare provider engagement

Engaging healthcare providers is a key pillar for the successful implementation of sodium reduction strategies. Physicians, nurses, dietitians, and pharmacists serve as trusted authorities for patients and play a pivotal role in influencing dietary behaviors, especially among individuals with hypertension or at a high risk of CVD. Summarizing international experience, the potential roles of healthcare providers in public policy on sodium reduction include the following.

4.4.1 Provider–patient education and counseling

Healthcare professionals are in a unique position to counsel patients about the health risks associated with high-sodium intake. According to the WHO, brief dietary interventions by primary care providers, particularly salt reduction, can lead to measurable improvements in BP control and lifestyle behaviors.⁶¹ In Taiwan, integrating sodium education with routine check-ups for patients with elevated BP or metabolic syndrome can significantly enhance public health outcomes.

4.4.2 Integration with clinical guidelines

Taiwan’s 2022 Guidelines for the management of hypertension recommend reducing sodium intake to 2-4 g/day (equivalent to 5-10 g salt/day) for better BP control and lower CV risk.⁷² More recent Taiwanese cardiovascular prevention guidance recommends a lower sodium intake of 2.4 g/day as part of broader CV risk management.⁷¹ This approach is consistent with contemporary hypertension guidelines that integrate sodium restriction and potassium intake into lifestyle management.⁸⁹ Ensuring that healthcare professionals are trained to consistently implement these recommendations through continuing medical education (CME) and electronic clinical decision support tools can help bridge the gap between policy and practice.

4.4.3 Role in community outreach and screening

Healthcare providers can extend their influence beyond clinics. For example, community health nurses and pharmacists can participate in mobile BP screening campaigns or educational events and offer individualized salt reduction tips. In Japan, provider-led community programs have demonstrated significant reductions in sodium intake and SBP.⁹¹ Taiwan can adopt similar strategies through training providers to lead sodium awareness initiatives in schools, markets, and workplaces.

4.4.4 Partnership with dietitians and nutritionists

Dietitians are essential for guiding patients through practical dietary changes in public food service policies.⁹⁸ Empowering providers to refer patients to dietitians for sodium-focused nutritional counseling can enhance patient adherence and outcomes.

4.5 Monitoring, evaluation, and accountability

This section integrates the monitoring framework and expected outcome metrics into a unified system that connects actions, measurable indicators, and accountability mechanisms across all implementation stakeholders. It aims to ensure that every sodium reduction initiative, from policy to community practice, can be tracked, evaluated, and refined in a data-driven manner.

Given the inherent limitations of self-reported dietary assessments, we suggest that Taiwan adopt a triangulation approach for sodium intake surveillance. The NAHSIT has collected sodium intake data from 24-hour dietary recall and urinary sodium markers from overnight urine since 1993. These methodologies can continue to serve as the primary source for monitoring population trends, dietary sources of sodium, and subgroup disparities. Using validation models, these data have been used to estimate 24-hour electrolyte excretion such as daily sodium and potassium excretion, and Na/K ratio. Discrepancies between dietary and urinary estimates are anticipated due to discretionary salt use and recall bias and will be interpreted as complementary information rather than conflicting results. We propose that periodic 24-hour urinary collection may be conducted on representative subsamples every two years to validate intake estimates and assess policy impact.

In addition, although 24-hour urinary sodium excretion (24h-U) is considered the gold standard to assess sodium intake,^49-51 its implementation in large-scale and repeated national surveys is resource-intensive. Methodological reviews cited in this consensus indicate that spot urine–based estimation methods using predictive equations such as the Kawasaki and Tanaka formulas have been applied as pragmatic alternatives for population surveillance.

The Kawasaki formula estimates 24-hour sodium excretion from second morning void urine, combining urinary sodium-to-creatinine ratios with predicted 24-hour creatinine excretion derived from anthropometric variables.¹⁰⁴ In contrast, the Tanaka formula uses casual spot urine samples and regression-based prediction of creatinine excretion to estimate mean population sodium intake.¹⁰⁵

While these equations are subject to individual-level measurement error and may be influenced by dietary patterns and timing of urine collection, evidence suggests that they can provide acceptable estimates of mean population intake and temporal trends when applied consistently within the same population. Accordingly, this consensus recommends a tiered monitoring framework in Taiwan, in which periodic 24-hour urine collections are complemented by interim spot urine surveys using validated equations such as the Kawasaki or Tanaka formula, with explicit acknowledgment of their methodological limitations.

Table 2 outlines the Taiwan Sodium Reduction Roadmap, detailing a Ministry of Health and Welfare (MOHW)-led governance framework supported by real-time dashboard monitoring and biennial NAHSIT-based evaluations to ensure transparent, evidence-based accountability.

Table 2. The Taiwan sodium reduction roadmap: governance, indicators, and milestones.

Intervention domain	Key performance indicator (KPI)	Baseline (2026)	2028 Target	2030 target	Data source	Lead agency	Frequency
Population intake	Mean daily sodium intake (g/day).	~3.45 g	< 3.0 g	< 2.3 g	NAHSIT (24h-U)	HPA	Biennial
Food industry	% of core food categories meeting sodium reduction targets.	0	50%	100%	Food Compendium	TFDA	Annual
Labeling	Prevalence of Front-of-Pack Labeling (FOPL) on packaged foods.	N/A	> 30%	> 80%	Market Surveys	HPA/TFDA	Annual
Public catering	% of hospitals/schools adopting low-sodium procurement.	N/A	50%	100%	Procurement Records	HPA/MOE	Annual
Clinical practice	% of hypertensive patients informed about potassium-enriched salt substitutes as an option.	< 5%	> 15%	> 40%	NHIRD/NHIS	TSOC/THS/ILSI/NST	Biennial
Public awareness	% of population aware of the < 2.3 g/day sodium limit.	Low	> 50%	> 80%	NHIS	HPA	Biennial

Abbreviations are defined in the main Abbreviations section.

4.5.1 Overall framework

The implementation of a national sodium reduction strategy should be accompanied by clearly defined outcomes and metrics to evaluate its effectiveness over time. These indicators will not only help monitor progress but also ensure accountability and drive evidence-based policy refinement. After reviewing international experience and considering the current situation in Taiwan,^24,61,91 M&E activities will follow a logic model approach linking inputs, outputs, outcomes, and impacts. Monitoring will capture program performance indicators on an annual basis, while evaluation will assess population-level health outcomes every two to three years.

Key domains include:

1. Population dietary sodium and potassium intake (24-h urinary Na, K, Na/K ratio).⁶¹

2. Food environment sodium density (processed and prepared foods in institutional meals, e.g., hospitals, workplaces, public canteens).¹⁰⁶

3. Policy implementation coverage (front of pack labeling, procurement standards, and LSSS uptake).

4. Clinical and healthcare engagement (documentation of sodium reduction counseling and nutritional referrals). Health outcome surveillance should be integrated with existing national databases. Long-term trends in BP, prevalence of hypertension, and CV morbidity and mortality, as captured by the NHI system and National Health Interview Surveys, can provide crucial indicators of policy effectiveness.

5. Behavioral and knowledge indicators (public awareness and self-reported use of low-sodium salt). Consumer knowledge and behavior should also be evaluated. Regular surveys assessing KAP can capture changes in public awareness, salt use behavior, and acceptance of salt substitutes, providing feedback on the reach and impact of educational campaigns.¹⁰⁶

All indicators will be harmonized with the WHO Global Sodium Benchmark framework to facilitate international comparability.

4.5.2 Proposed key performance indicators (KPIs)

The proposed KPIs translate these monitoring and evaluation domains into measurable indicators across population intake, the food environment, policy implementation, healthcare engagement, and health outcomes, with corresponding data sources and monitoring frequencies, as summarized in Table 3.

Table 3. Proposed monitoring and evaluation indicators for Taiwan’s sodium reduction strategy.

Domain	Indicator	Data source/frequency
Population intake	Mean 24-h urinary Na (g/day)61	National Urinary Na Survey (2-year cycle)
	Mean Na/K ratio	Same as above
Food environment	Products meeting sodium benchmark (%)	Annual market survey
	Front-of-pack “high-sodium” labeling coverage (%)	Label audit (annual)
	Average Na content in public institutional meals (including schools, hospitals, and workplaces) (mg/meal)	School procurement records
Low-sodium salt (LSSS)	Public household use of LSSS (%)	Knowledge, attitudes, and practices (KAP) survey (3-year cycle)
	Public institution kitchen adoption rate (%)	Procurement monitoring (annual)
Healthcare system	Hypertensive patients receiving sodium coun-seling (%)	Hospital quality assurance (QA) audit (annual)
	Patients referred to a dietitian (%)	Electronic medical record (EMR) review (annual)
Outcome indicators	Hypertension prevalence (%)3	National Health Survey
	Mean SBP reduction (mmHg vs. baseline year)
	CVD mortality attributable to high Na (%)61	Vital stats/modeling (3-year cycle)

Each key performance indicator (KPI) will include a data quality criterion (sample size, representativeness, and verification protocol) to ensure the statistical robustness and transparency of reporting.

4.5.3 Accountability flow and governance

Establishing a transparent and coordinated accountability mechanism is essential to ensure the effective implementation, monitoring, and evaluation of sodium-reduction policies. This governance framework (Figure 4) delineates the flow of responsibility among national authorities, research institutions, and stakeholders, linking operational activities with measurable KPIs. To ensure that sodium-reduction progress is accurately tracked over time, we recommend that the government conduct biennial routine urinary sodium sampling surveys as part of the national monitoring framework. These data will function as an objective metric for assessing policy efficacy and informing regular strategic modifications. A schematic flow diagram illustrating the operational framework for national monitoring through five key stages is presented in Figure 5.

Figure 4.

Accountability, KPI flow, and feedback mechanism. HPA, Health Promotion Administration; KPI, key performance indicator; MOHW, Ministry of Health and Welfare; NHRI, National Health Research Institutes; TFDA, Taiwan Food and Drug Administration.

Figure 5.

Monitoring and sampling framework.

1. Population Stratification: Participants will be selected to ensure representativeness across strata defined by urban or rural residence, geographic region, age, and sex.

2. Sampling Design: A two-stage cluster sampling strategy with a rotating panel of approximately 2,000 adults per cycle will be implemented to balance statistical precision and operational feasibility.

3. Data Collection: Standardized procedures will be used to obtain 24-hour urine specimens and spot urine subsamples complemented by dietary recall, front-of-pack labeling audits, and procurement record reviews.

4. Integration and Analysis: All datasets will be consolidated into a centralized database managed by the MOHW under the technical supervision of the National Health Research Institutes.

5. Feedback and Dissemination: Findings will be summarized in annual policy briefs submitted to the Taiwan Food and Drug Administration and made publicly available via an online dashboard. Comprehensive technical reports will be issued biennially to inform stakeholders and guide strategic policy adjustments.

All data collection protocols will adhere to international quality management standards, with ethical approval and participant consent obtained for biological samples.

4.5.4 Feedback and continuous improvement

The evaluation findings will be reviewed annually by the National Level Sodium Reduction Steering Committee to identify bottlenecks and prioritize corrective actions. Data-driven recommendations will be fed back to policymakers and implementers through structured reporting templates and public communication platforms.

Every three years, an independent review panel comprising clinical, nutritional, and epidemiological experts will conduct mid- and end-term evaluations to validate progress and recommend revisions of numeric targets based on new evidence.

4.6 Economic impact assessment

Estimating the economic effects of sodium reduction is crucial for policymaking, especially in Taiwan, where hypertension-related costs constitute a substantial component of national healthcare expenditure. International modelling studies have provided evidence of both direct medical cost savings and broader societal benefits from reducing sodium intake.

A systematic review across multiple countries demonstrated that population-wide sodium reduction interventions were among the most cost-effective public health measures for reducing the burden of NCDs. Webb et al. (2017) estimated that a 10% reduction in sodium consumption globally over 10 years could avert approximately 5.8 million deaths, substantially reducing healthcare costs.⁵⁷ In the United States, reducing sodium intake to meet the proposed voluntary U.S. Food and Drug Administration reformulation targets was projected to prevent approximately 450,000 cases of CVD, generate ~2.1 million quality-adjusted life years (QALYs), and yield net discounted cost savings of approximately US$41 billion over a 20-year period.¹⁰⁸

Another study in New Zealand showed that substituting a large proportion of sodium in processed foods with potassium and magnesium salts produced net cost savings of approximately NZ$1.5 billion (≈ US$1.0 billion) and significant health gains over the lifetime of the cohort.¹⁰⁹ In Japan, policy simulations using English salt-reduction intervention scenarios have estimated that mandatory reformulation combined with labeling and other measures could deliver net benefits over policy costs over a 10-year period.⁵⁹

Applying these findings to Taiwan suggests that modest reductions in population sodium intake (e.g., 10-20%) could yield significant medical cost savings, reduced medication use, fewer hospitalizations for CV events, and lower long-term morbidity and mortality. In addition to direct healthcare cost savings, Taiwan can anticipate productivity gains (owing to fewer days of illness and reduced disability) as well as savings in public health infrastructure, particularly with the decreasing burden of treating end-stage renal disease, heart failure, stroke, and related complications.

To quantify this locally, economic modeling and continuous tracking is required in Taiwan. Conducting cost-effectiveness or cost-benefit analyses of specific interventions (e.g., reformulation, salt substitutes, and labeling) will support the prioritization of policies by return on investment.

In summary, international evidence strongly supports that sodium reduction is not only medically beneficial but also economically favorable. In Taiwan, the implementation of evidence-based sodium reduction strategies represents an opportunity to simultaneously achieve substantial cost savings and improve population health. Careful economic impact assessments with Taiwan-specific data will promote the case for policy adoption, guide the allocation of resources, and maximize returns for both health and economic outcomes.

4.7 Implementation challenges, risks, and mitigation strategies in Taiwan

4.7.1 Regulatory and food environment challenges

A major implementation challenge in Taiwan are the high contributions of processed foods, out-of-home dining, and traditional condiments to total sodium intake. Evidence from the NAHSIT indicates that discretionary salt use and sodium-rich seasonings remain prominent contributors across age groups, particularly among working-age adults.

Although Taiwan has adopted voluntary sodium reduction targets and nutrition labeling policies, the absence of mandatory reformulation thresholds may limit the magnitude and consistency of sodium reduction across the food supply. International experience summarized by the WHO indicates that voluntary approaches alone often result in varying compliance across manufacturers.

To mitigate these barriers, the consensus recommends a phased approach combining voluntary reformulation targets with enhanced monitoring, transparent benchmarking, and gradual tightening of sodium targets in high-contribution food categories, consistent with WHO best practices.

4.7.2 Cultural dietary practices and public acceptance

Traditional Taiwanese dietary patterns, including the frequent consumption of soups, preserved foods, and sodium-rich condiments, pose additional challenges to sodium reduction. Cultural preferences for taste intensity and the perception that low-sodium foods are less palatable may undermine adherence to dietary recommendations.

Public awareness campaigns alone may be insufficient to achieve sustained behavior change without concurrent environmental support.

The consensus therefore emphasizes taste-adaptive strategies, including gradual sodium reduction, promotion of potassium-enriched salt substitutes, and collaboration with the food service sector to preserve palatability while reducing sodium content.

4.7.3 Health system and clinical practice barriers

From a healthcare perspective, challenges to implementation include variability in clinician awareness, time constraints in outpatient settings, and limited integration of dietary sodium assessment into routine care. While hypertension guidelines emphasize sodium reduction, consistent translation into patient counseling remains uneven, particularly in primary care and community settings.

Collaboration with professional medical teams is essential to distribute standardized educational toolkits. Incorporating a simplified dietary assessment into routine practice through a multidisciplinary integrated care team comprising physicians, dietitians, pharmacists, and nurses can enhance feasibility and ensure that sodium-reduction efforts are seamlessly aligned with existing chronic disease management and medication counseling.

4.7.4 Risks associated with potassium-enriched salt substitutes

While potassium-enriched salt substitutes represent a pragmatic intervention with strong evidence for CV benefit, inappropriate use among high-risk populations may pose safety concerns, particularly in individuals with advanced CKD, hyperkalemia, and those who use potassium-sparing medications.

The consensus recommends a risk-stratified implementation framework, including clear labeling, clinician guidance, and targeted public education, rather than universal substitution without safeguards.

4.7.5 Monitoring, evaluation, and sustainability

Sustained implementation requires robust M&E frameworks. While 24h-U remains the gold standard, practical constraints necessitate complementary approaches for routine surveillance.

Taiwan may adopt the framework inspired by US¹⁰⁹ and UK¹¹⁰ models, establishing "target mean sodium levels" and sales-weighted averages (SWA) across food categories, including the out-of-home sector. By integrating SWA with the specific KPIs of urinary sodium level and product benchmark compliance defined in Section 4.4.2, the framework ensures that sodium reduction targets remain both measurable and accountable. Integrating commercial purchase data with laboratory and menu monitoring enhances transparency, while a phased progress-sharing mechanism provides reputational recognition for proactive businesses. Simultaneously, tracking overall nutrient quality ensures that sodium reduction supports population CV health without compromising dietary quality. This collaborative approach will foster public trust and ensure the long-term sustainability of the food environment.

4.8 Safe adoption of potassium-enriched salt substitutes: risk stratification and clinical considerations

While potassium-enriched salt substitutes may contribute to BP reduction and CV risk mitigation at the population level, their use requires appropriate risk stratification. Such products are suitable for the general adult population without known disorders of potassium metabolism. However, individuals with advanced CKD, a history of hyperkalemia, or those receiving RAAS inhibitors, potassium-sparing diuretics, or mineralocorticoid receptor antagonists should avoid or use potassium-enriched salt substitutes with caution and under medical supervision.^6,111 For these populations, routine monitoring of serum potassium is recommended to minimize the risk of adverse events.

5. CONSENSUS STATEMENT

The health implications of excessive sodium intake extend far beyond BP and CVDs. High sodium levels contribute to renal injury and stone formation, increase the risk of gastric cancer, compromise bone health, affect immune regulation and cognitive dysfunction, and are associated with features of metabolic dysfunction. High-quality evidence indicates that excessive sodium intake increases BP and CVD risks, particularly among those with hypertension. Although methodological debates persist, global data support public health efforts to reduce sodium intake as a key strategy for lowering CV mortality and improving population health.

Given these considerations, the expert panel issued the following recommendations for sodium reduction in Taiwan:

(1) Establish a national goal to reduce mean sodium intake to < 2.3 g/day by 2030, with interim reductions of 10-15% every 3-5 years, which should be governed by a national-level sodium reduction steering committee, with accelerated reductions in later phases.

(2) Promote increased potassium intake (> 3.5 g/day) and target a urinary Na/K ratio < 1.5 through dietary improvements and/or salt substitutes, while exercising caution in vulnerable populations.

(3) Implement national surveillance through the assessment of 24-hour urinary sodium and potassium excretion, supplemented by dietary surveys, to track trends in sodium and potassium intake, thereby informing interventions and illustrating the effects of the national sodium reduction policy.

(4) Mandate explicit, front-of-pack sodium labeling and enforce maximum sodium content standards in key food categories.

(5) Prioritize reformulation of sauces, condiments, and processed foods, with phased mandatory targets and incentives for industry compliance.

(6) Enforce sodium standards in institutional food services, including schools, hospitals, military, and elder care facilities.

(7) Promote culturally appropriate communication-based strategies, including media campaigns, schools, and community education, to shift taste preferences and consumer behaviors.

(8) Encourage the safe adoption of potassium-enriched salt substitutes, along with professional education for healthcare providers and patients.

(9) Support research on the cost-effectiveness, feasibility, and consumer acceptance of sodium-reduction strategies tailored to the dietary patterns and food culture in Taiwan.

(10) Promote multi-sectoral collaboration among government, academia, healthcare professionals, industry, and civil society to ensure coordinated implementation and accountability.

This consensus underscores the importance of sodium reduction and potassium enhancement as urgent, achievable, and cost-effective strategies. Through sustained commitment and phased implementation, Taiwan can substantially reduce the burden of hypertension, CVD, and related conditions while delivering significant health and economic benefits.

The consensus acknowledges ongoing academic debate regarding J-shaped associations between sodium intake and CV outcomes, as well as physiological concerns related to neurohormonal activation at very low sodium intake levels. Evidence cited in this manuscript indicates that such associations are primarily observed in observational studies subject to reverse causation and measurement error, particularly among individuals with pre-existing illness.

Importantly, this consensus does not advocate for sodium intake below levels required for basic physiological needs. Rather, the public health goal is to reduce excessive sodium intake toward recommended ranges that balance CV benefit and physiological adequacy. The proposed targets aim to shift the intake distribution of the general population from excessive levels toward moderate intake, rather than promoting extreme sodium restriction.

DECLARATION OF CONFLICT OF INTEREST

All the authors declare no conflict of interest.

AUTHOR CONTRIBUTIONS

Conceptualization, HMC, WYY, WHP, YJW, HHL, JYD, TJL; methodology, HMC, HHL, AMH, PCL, BHT, WCL; literature review, HMC, WYY, WHP, YJW, HHL, JYD, TJL, AMH, PCL, BHT, WCL; writing — original draft preparation and editing, HMC, WYY, WHP, YJW, HHL, JYD, TJL, AMH, PCL, BHT, WCL; Review and editing, CJH, SMY, JCJC, SCY, CCW, AYHL, YHL; visualization, HMC, HHL, AMH, PCL, BHT, WCL. All authors have read and agreed to the published version of the manuscript.