Table 1.
Summary for other implementation studies
| A. Monitoring or surveillance studies: population salt intake (n=11) | |||||
|---|---|---|---|---|---|
| Study | Country | Study Design | Study Population | Method of Assessment | Results |
| Goncalves15 | Portugal | Cross‐sectional study | Adolescents aged 13–18 y (n=200) | One 24‐h urine collection | Mean urinary sodium excretion was 3725 mg/d and 3062 mg/d in boys and girls, respectively, with only 9.8% of boys and 22% of girls meeting the WHO recommendations for sodium intake. |
| An16 | United States | Secondary analysis of NHANES cross‐sectional data | Adults aged 18 y and older (n=11 646) | Two 24‐h dietary recalls | Weekend diet was associated with an increase in daily intake of sodium by 205.59 mg and increase in the prevalence of fast‐food (10.21%) and full‐service restaurant consumption (17.79%). |
| Jackson17 | United States | Secondary analysis of NHANES cross‐sectional data | Individuals aged 2 y and older (n=14 728) | Two 24‐h dietary recalls | Eighty‐nine percent of adults (≥19 y) and >90% of children (2–18 y) exceeded age‐specific recommendations for sodium intake. |
| Land8 | Samoa | Cross‐sectional study | Women aged 18–45 y (n=152) | One 24‐h urine collection | Mean 24‐h salt excretion among women was 6.6 g/d (SD: 3.2 g/d), with more than two thirds of the women exceeding the WHO‐recommended daily maximum level. |
| Okuda18 | Japan | Cross‐sectional study | Secondary school adolescents aged 12–15 y (n=68) | Two 24‐h urine collections and three overnight urine collections | Estimated salt intake was 10.6 g/d (SD: 1.2 g/d) for boys and 10.0 g/d (SD: 2.4 g/d) for girls. Sodium excretion was associated with physical activity but not body weight. |
| Service19 | Australia | Cross‐sectional study | Primary school children (n=168) and their parents (n=148) | One 24‐h urine collection and dietary habits questionnaire | A 1 g/d increase in mother's salt intake was associated with a 0.2 g/d increase in child's salt intake, after adjusting for parental age, child age, and sex. There was no association between father's salt intake and child's salt intake. Sixty‐seven percent of parents added salt during cooking while 37% of children added salt at the table. |
| Sobiecki20 | United Kingdom | Secondary analysis of cross‐sectional data from EPIC‐Oxford cohort study | Adults aged 30–90 y (n=30 251) | One semi‐quantitative food frequency questionnaire, which had no measure of table salt use | There was no statistically significant (P>.05) difference in mean sodium intake between the four dietary groups (meat eaters, fish eaters, vegetarians, and vegans). The means from all groups exceeded the recommended daily sodium intake of 2400 mg/d and ranged from 2624 to 2701 mg/d. |
| Rehm21 | United States | Secondary analysis of repeated cross‐sectional data from NHANES | Adults aged 20 y and older (n=33 932) | One or two 24‐h dietary recalls | No significant change was demonstrated for sodium intake over the period 1999–2012, with estimated mean sodium intakes ranging from 3355 mg/d in 2001–2002 to 3557 mg/d in 2006–2006. |
| O'Halloran22 | Australia | Secondary analysis of data from the Melbourne InFANT program | Preschool children aged ≈3.5 y (n=251) | Three 24‐h dietary recalls | Mean daily sodium intake was 1565 mg/d in boys and 1452 mg/d in girls, and was significantly higher among those with adequate intake of potassium. The major sources of sodium were milk products, cereal products, and meat products. |
| Wang23 | China | Secondary analysis of cross‐sectional data from CRHI‐SRS | Adults aged 20 y and older (n=1903) | Survey and one 24‐h urine collection | The effect of the salt reduction intervention (in terms of salt intake, potassium intake, sodium to potassium ratio, and KAB) did not vary across different levels of education. Among all educational groups, salt intake was lower in the intervention than in the control group. |
| Kang24 | Korea | Secondary analysis of cross‐sectional data from KNHANES IV and V | Adults older than 30 y with (n=12 477) and without diabetes (n=1480) | One 24‐h dietary recall | Healthy individuals had higher mean sodium intake than diabetics (5188.2 mg/d vs 4910.2 mg/d, P>.1). Among diabetics, those who were newly diagnosed had higher sodium intake than those who were formerly diagnosed (P>.1). All groups consumed more than the recommended sodium intake per day. |
| B. Monitoring or surveillance studies: salt content in foods and meals (n=3) | |||||
|---|---|---|---|---|---|
| Study | Country | Study Design | Type of Foods Assessed | Source of Sodium Information | Results |
| Kraemer25 | Brazil | Cross‐sectional study | Processed snack foods consumed by children and adolescents (n=2945) | Nutrition information panel | Twenty‐one percent of processed foods had high levels of sodium (>600 mg/100 g) while 35% had medium sodium levels (>120 and ≤600 mg/100 g). |
| Prentice26 | New Zealand | Cross‐sectional study | Savoury fast foods from chain restaurants (n=471) and independent outlets (n=52) | Nutrition information from company Web sites and food analysis for foods sourced from independent outlets | The majority of fast foods exceeded the UK Food Standards Agency 2012 sodium targets. Sauces, salad dressings, and fried chicken had the highest sodium content from chain restaurants, while from independent outlets, sausage rolls, battered hotdogs, and mince and cheese pies had the highest. |
| John27 | United States | Cross‐sectional study | Regular foods (savoury snacks, cheese, salad dressings, soups) and their lower‐calorie or lower‐fat food counterparts (n=283 matches) | Nutrient information from manufacturers’ Web sites | Changes in sodium content from calorie and fat modification varied by food category. Mean sodium content of modified soups was significantly lower compared with regular soups. Modified salad dressings and cheeses had slightly higher mean sodium content, while modified savoury snacks had similar mean sodium content as regular versions. |
| C. Monitoring or surveillance studies: consumer's KABs related to salt (n=7) | |||||
|---|---|---|---|---|---|
| Study | Country | Study Design | Study Population | Method of KAB Assessment | Results |
| Rasheed28 | Bangladesh | Cross‐sectional mixed method study | Adults aged 18 y and older (n=400 for the quantitative survey) | Focus group discussion, key informant interview, and survey | Participants had low awareness of the risks associated with excess salt consumption, and many reported that salt was beneficial to health. Salt reduction strategies were not a priority for participants. |
|
John29 |
United States | Secondary analysis of cross‐sectional data from Porter Novelli's ConsumerStyles online database | Adults aged 18 y and older (n=6378) | Online survey | Sixty‐eight percent of the respondents agreed that it is important for baby or toddler foods to be low in sodium. Adjusted analysis showed that agreement was most strongly associated with being a parent of a child <2 y, thinking sodium was harmful, and watching or reducing own sodium intake. |
| Regan30 | Ireland | Cross‐sectional study | Adults aged 18 and older (n=501) | Online survey | The majority of respondents supported 11 of 13 government‐led salt reduction policies (both voluntary and regulated, including education, labeling, and salt restriction in foods). Fewer participants supported subsidizing low‐salt foods and taxing high‐salt foods. |
| Lee31 | South Korea | Cross‐sectional study | Food service personnel at worksite cafeterias (n=104) | Survey | Most of the participants regarded sodium reduction as very or moderately important. The biggest barriers to providing sodium‐reduced meals were use of processed foods and limited methods of sodium‐reduced cooking in worksite cafeterias. |
| Sugimoto32 | Japan | Cross‐sectional study | Female dietitians (n=99) and nondietitians (n=117) aged 20–69 y at welfare facilities | Survey, two 24‐h urine collections, and 4‐d semi‐weighted diet records | Nutritional knowledge and dietary behavior were moderately associated with sodium to potassium ratio, but not with either sodium or potassium excretion. |
| Quader33 | United States | Secondary analysis of repeated cross‐sectional data from NHANES | Individuals aged 2 y and older (n=38 896) | Dietary habits questionnaire for participants and/or proxy (for children) | Use of salt “very often” at the table and during home cooking both declined from 18% to 12% and from 42% to 37%, respectively, between 2003 and 2012. There was no change in the proportion of the population who never used discretionary salt. Discretionary salt use differed by age, race or ethnicity, body mass index, self‐reported diabetes status, and income. |
| Asakura34 | Japan | Cross‐sectional study | Adults aged 20–69 y (n=392) | Four semi‐weighted diet records and two 24‐h urine collections | The proportion of sodium from discretionary sources was more than 50% in both sexes and was found to be lower in younger patients. The major contributors to sodium intake differed by age, but the top contributors were similar for both sexes (seasonings such as salt, and fish and shellfish). |
| D. Economic evaluations or modeling studies: effects of salt reduction (n=5) | ||||
|---|---|---|---|---|
| Study | Country | Intervention | Outcome Measure | Results |
| Wilson35 | New Zealand | Achievement of full and component food category sodium reduction targets (total of 10 targets) | Health gains measured by QALY and cost‐savings | Achieving the full target (overall 35% reduction in dietary salt intake through the mandatory approach) would have the largest health gain (235 000 QALYs) and the greatest cost‐savings (NZD 1260 million). For specific target components, the range of health gain was from 122 000 to 6100 QALYs. All 10 target interventions were cost‐saving. |
| Souza36 | Brazil | Reduction of sodium content in processed foods based on voluntary agreements between the government and food industry | Average salt intake | Sodium reduction targets in processed foods based on voluntary agreements would have a small impact on mean salt intake of the Brazilian population. The estimated mean sodium intake reduction 5 y after the agreement was 1.5%. |
| van Buren37 | Netherlands | Reformulation: replacing sodium chloride with potassium chloride (total of three reformulation scenarios) | Dietary impact and potassium intake | 20%, 50%, and 100% replacement scenarios would lead to an increase in the median intake of potassium by 453 mg/d, 674 mg/d, and 733 mg/d, respectively, which would result in better compliance to potassium intake guidelines. Reformulation would have the largest impact on bread, processed fruits and vegetables, snacks, and processed meat. |
| Watkins38 | South Africa | Salt reduction policy: reducing salt consumption to the target of 5 g/d | Health impacts measured by reductions in cardiovascular disease, and economic impacts | Reducing salt consumption to the target of 5 g/d could reduce the burden of cardiovascular disease by 11%, could save households $4.06 million in out‐of‐pocket expenditures, and save the government $51.25 million in healthcare subsidies yearly. |
| Nghiem39 | New Zealand | Salt substitution and setting maximum levels of sodium in breads (total of four interventions) | Health gains measured by QALYs and cost‐savings | The intervention where most (59%) of the sodium in processed foods was replaced by potassium and magnesium salts had the largest health gain (294 000 QALYs) and the highest net cost‐savings (NZD 1.5 billion). All interventions resulted in relatively larger per capita QALYs for men than women and for the indigenous Maori population than non‐Maori. |
| E. Other studies related to salt reduction interventions (n=10) | ||||
|---|---|---|---|---|
| Study | Country | Type of Study | Subject | Results |
| Jezewska‐Zychowicz40 | Poland | Acceptability of low‐sodium foods–survey of adult consumers | Bread | Self‐reported willingness to consume breads produced without preservatives or raising agents was higher than reduced‐salt breads. Women, people older than 55 y, and people who often consume white breads were more willing to consume reduced‐salt breads, while those with a higher education, who were older than 45 y, and who rarely consume wholemeal bread were more willing to eat bread without preservatives or raising agents. |
| McMahon41 | Australia | Acceptability of low‐sodium foods–consumer taste test | Bread | The difference between standard and reduced‐salt breads was not detected by the participants. Further, there was no significant difference in overall liking between the two breads. |
| De Kock42 | South Africa | Acceptability of low‐sodium foods–consumer taste test | Chicken stew | The standard chicken stews and chicken stews prepared with reduced‐salt stock powders were equally well liked by the consumers; however, 19% of consumers added salt back at the table, with more salt being added with increased salt reduction in the meals, to the point of full compensation in some cases. |
| Peng43 | China | Validity of tools or assessment methods | Spot urine to estimate 24‐h urinary sodium excretion vs 24‐h urine collection | The Kawasaki, INTERSALT, and Tanaka methods underestimated the measured 24‐h urinary sodium excretion in the sample of Chinese adults. The Kawasaki method was least biased (mean bias –740 mg/d), followed by the Tanaka method (mean bias –2305 mg/d), and the INTERSALT method (mean bias –2797 mg/d). |
| Yasutake44 | Japan | Validity of tools or assessment methods | Overnight (8‐h) urine samples obtained using a self‐monitoring device vs 24‐h urine collection | There was a significant positive correlation between 24‐h urine salt and overnight urine salt; however, the coefficients of variation for the overnight urine were lower than those for the 24‐h urine, suggesting a narrow measurement range for the self‐monitoring device. |
| Mizehoun‐Adissoda45 | Benin | Validity of tools or assessment methods | Spot urine to estimate 24‐h urinary sodium excretion vs 24‐h urine collection | Mean sodium chloride and potassium chloride excretion from 24‐h urine were 10.2 g/d and 2.9 g/d, respectively, while the estimated values from spot urine were 10.7 g/d and 3.9 g/d, respectively. Spot urine is an acceptable method to assess sodium and potassium intake in black populations, but its high variation limits its application in clinical settings. |
| Ma46 | China | Validity of tools or assessment methods | Salt sales survey to estimate 24‐h urinary sodium excretion vs 24‐h urine collection | The results from the salt sales survey were consistent with the results from 24‐h urine and potassium data. The salt sales survey cost only 14% of the cost of the 24‐h urine method and had greater statistical power. |
| Sugimoto32 | Japan | Validity of tools or assessment methods | 24‐h urine collection vs 4‐d semi‐weighted diet record vs two validated diet history questionnaires | All dietary assessment methods underestimated salt intake measured from 24‐h urinary collection. Correlation coefficients between 24‐h urine collection and diet record were higher than the two validated diet history questionnaires for sodium, potassium, and protein. Compared with nondietitians, dietitians were more likely to underreport sodium and protein intake and overreport potassium intake. |
| Muthuri12 | Sub‐Saharan Africa | Systematic review related to salt intake | Effectiveness of salt reduction interventions | All interventions had at least one significantly improved outcome measure, including reduction in 24‐h urinary sodium excretion, systolic blood pressure, or mean arterial blood pressure. |
| Huang13 | Global | Systematic review related to salt intake | Spot urine to estimate 24‐h urinary sodium excretion vs 24‐h urine collection | The average population salt intake estimated from 24‐h urine samples and spot urine samples were 9.3 g/d and 9.0 g/d, respectively. Spot urine samples overestimated salt intake at lower levels of consumption and underestimated intake at higher levels of consumption. |
Abbreviations: CRHI‐SRS, China Rural Health Initiative–Sodium Reduction Study; EPIC, European Prospective Investigation into Cancer and Nutrition; InFANT, Infant Feeding Activity and Nutrition Trial; KAB, knowledge, attitudes, and behaviour; KNHANES, Korean National Health and Nutrition Examination Survey; NHANES, National Health and Nutrition Examination Survey; NZD, New Zealand dollar; QALY, quality‐adjusted life year; SD, standard deviation; WHO, World Health Organization.