Dietary Salt Intake and Discretionary Salt Use in Two General Population Samples in Australia: 2011 and 2014

Knowledge, attitudes, and behaviors related to dietary salt intake and the acceptability of salt substitute among the Australian culturally and linguistically diverse community: An online survey

The Australian culturally and linguistically diverse (CALD) communities may be at higher risk of salt intake than recommended given the use of a combination of discretionary sources and exposure to processed foods within a western country. This survey aimed to understand the knowledge, attitudes, and behaviors toward dietary salt and the acceptability of salt substitutes in the CALD communities. An online cross-sectional survey was conducted among adults who self-reported being a part of a CALD community, which was defined as non-Indigenous cultural groups in Australia having cultural or linguistic connections with their overseas place of birth, ancestry or ethnic origin, religion, preferred language or language spoken at home. A total of 218 respondents opened the survey link. A total of 196 completed the entire survey. The majority of respondents (162, 83%) were aware that high salt intake causes serious health problems. Altogether 134 (69%) respondents were aware that there is a recommended amount for daily salt consumption although only 59 (44%) knew precise recommendations as <5 g salt per day. Around one quarter of the respondents rarely or never looked for ‟low in salt'' or ‟reduced salt'' messages on food labels when shopping. Over half specified they always or often added salt during cooking or preparing foods in the household. Almost 4 in 5 CALD respondents were willing to reduce their salt intake for health and 3 in 4 were open to trying a salt substitute. Further research into the utility of a salt substitute intervention in the Australian CALD community is warranted.

Associations between protein to non-protein ratio and intakes of other dietary components in a cohort aged 65-75 years: the Nutrition for Healthy Living Study

OBJECTIVE

Diets with a low proportion of energy from protein have shown to cause overconsumption of non-protein energy, known as Protein Leverage. Older adults are susceptible to nutritional inadequacy. The aim was to investigate associations between protein to non-protein ratio (P:NP) and intakes of dietary components and assess the nutritional adequacy of individuals aged 65-75 years from the Nutrition for Healthy Living (NHL) Study.

DESIGN

Cross-sectional. Nutritional intakes from seven-day weighed food records were compared with the Nutrient Reference Values for Australia and New Zealand, Australian Guide to Healthy Eating, Australian Dietary Guidelines and World Health Organisation Free Sugar Guidelines. Associations between P:NP and intakes of dietary components were assessed through linear regression analyses.

SETTING

NHL Study.

PARTICIPANTS

113 participants.

RESULTS

Eighty-eight (59 female and 29 male) with plausible dietary data had a median (interquartile range) age of 69 years (67-71), high education level (86 %) and sources of income apart from the age pension (81 %). Substantial proportions had intakes below recommendations for dairy and alternatives (89 %), wholegrain (89 %) and simultaneously exceeded recommendations for discretionary foods (100 %) and saturated fat (92 %). In adjusted analyses, P:NP (per 1 % increment) was associated with lower intakes of energy, saturated fat, free sugar and discretionary foods and higher intakes of vitamin B12, Zn, meat and alternatives, red meat, poultry and wholegrain % (all P < 0·05).

CONCLUSIONS

Higher P:NP was associated with lower intakes of energy, saturated fat, free sugar and discretionary. Our study revealed substantial nutritional inadequacy in this group of higher socio-economic individuals aged 65-75 years.

Outcomes of a state-wide salt reduction initiative in adults living in Victoria, Australia

PURPOSE

To assess any effects of a state-wide sodium reduction intervention on sodium intake, sources of dietary sodium and discretionary salt use at a population level.

METHODS

Data (24-h urinary sodium excretion, self-report survey, a 24-h dietary recall) were collected cross-sectionally at baseline (2016/2017) and follow-up (2020) from adults in Victoria, Australia. Intervention activities included consumer awareness advertising campaign, public debate generation via mass media, strengthening existing policy initiatives and supporting food innovation with industry.

RESULTS

There were 339 participants at baseline and 211 at follow-up, with 144 and 90 of participants completing a 24-h dietary recall, respectively. There was no difference in adjusted 24-h urinary sodium excretion between baseline and follow-up (134 vs 131 mmol/24 h; p = 0.260). There were no differences in the percentage of participants adding salt during cooking (63% vs 68%; p = 0.244), adding salt at the table (34% vs 37%; p = 0.400) or regularly taking action to control salt/sodium intake (22% vs 21%; p = 0.793). There were large differences in the quantity of dietary sodium sourced from retail stores (57% vs 77%, p < 0.001), and less sodium was sourced from foods at fresh food markets (13% vs 2%; p ≤ 0.001) at follow-up. No large differences were apparent for foods with different levels of processing or for food groups.

CONCLUSION

There was no clear population-level effect of the 4-year multi-component Victorian Salt Reduction Intervention on sodium intake with Victorian adults continuing to consume sodium above recommended levels. The findings indicate that more intensive and sustained efforts aiming at the retail and food industry with national level support are likely to be required to achieve a measurable improvement in sodium intake at a state level.

Age, time orientation and risk perception are major determinants of discretionary salt usage

The present work explored the relationship between discretionary salt usage and personal characteristics, using boosted regression trees (BRT). Specifically, the focus was on how socio-demographic characteristics and personality traits linked to risk perception and time orientation impact on discretionary salt consumption patterns. For this purpose, an online cross-sectional survey with a convenience sample of 498 Uruguayan participants was carried out. Participants completed the consideration of future consequences (CFC) scale adapted for eating behaviour, a short survey about discretionary salt consumption patterns and indicated their degree of agreement with statements measuring perceived risk of sodium consumption. Finally, socio-demographic data were collected. BRT were applied to build predictive models that related discretionary salt usage to socio-demographic characteristics, the two factors of the CFC-Food scale (consideration of the future and consideration of the immediate consequences of eating behaviour), and the two factors of the perceived risk of sodium consumption scale (severity of perceived risks and risk compensation). Age, time orientation and perceived risk were the most relevant explanatory variables for discretionary salt usage. Older people had a lower likelihood of adding salt to food, either at home or when eating out. In addition, individuals who tend to be present rather than future oriented, as well as those with low perception of risk severity and susceptibility were more likely to add salt to foods. Results from the present work suggest that communication campaigns to reduce discretionary salt intake should mainly focus on stressing the short-term health benefits of reducing sodium intake and raising perceived susceptibility.

Young Adults with Higher Salt Intake Have Inferior Hydration Status: A Cross-Sectional Study

The body’s water and sodium balances are tightly regulated and monitored by the brain. Few studies have explored the relationship between water and salt intake, and whether sodium intake with different levels of fluid intake leads to changes in hydration status remains unknown. The aim of the present study was to determine the patterns of water intake and hydration status among young adults with different levels of daily salt intakes. Participants’ total drinking fluids and water from food were determined by a 7-day 24-h fluid intake questionnaire for 7 days (from Day 1 to Day 7) and duplicate portion method (Day 5, Day 6 and Day 7). Urine of 24 h for 3 days (Day 5, Day 6 and Day 7) was collected and tested for the osmolality, the urine-specific gravity (USG), the concentrations of electrolytes, pH, creatinine, uric acid and the urea. The fasting blood samples for 1 day (Day 6) were collected and measured for the osmolality and the concentrations of electrolytes. The salt intakes of the participants were evaluated from the concentrations of Na of 24 h urine of 3 days (Day 5, Day 6 and Day 7). Participants were divided into four groups according to the quartile of salt intake, including the low salt intake (LS₁), LS₂, high salt intake (HS₁) and HS₂ groups. In total, 156 participants (including 80 male and 76 female young adults) completed the study. The salt intakes were 7.6, 10.9, 14.7 and 22.4 g among participants in the four groups (LS₁, LS₂, HS₁ and HS₂ groups, respectively), which differed significantly in all groups (F = 252.020; all p < 0.05). Compared to the LS₁ and LS₂ groups, the HS₂ group had 310–381, 250–358 and 382–655 mL more amounts of water from the total water intake (TWI), total drinking fluids and water from food (all p < 0.05), respectively. Participants in the HS₂ group had 384–403, 129–228 and 81–114 mL more in the water, water from dishes and staple foods, respectively, than those in the groups of LS₁ and LS₂ (p < 0.05). The HS₂ group excreted 386–793 mL more urine than those in the groups of LS₁ and LS₂ (p < 0.05). However, regarding urine osmolality, the percentage of participants with optimal hydration status decreased from 41.0% in LS₁ and LS₂ to 25.6% in the HS₂ group (p < 0.05). Participants with higher salt intake had higher TWI, total drinking fluids and water from food. Nevertheless, they had inferior hydration status. A reduction in salt intake should be encouraged among young adults to maintain optimal hydration status.

The estimated health impact of sodium reduction through food reformulation in Australia: A modeling study

BACKGROUND

The Australian Government recently established sodium targets for packaged foods to encourage voluntary reformulation to reduce population sodium consumption and related diseases. We modeled the health impact of Australia's sodium reformulation targets and additional likely health gains if more ambitious, yet feasible sodium targets had been adopted instead.

METHODS AND FINDINGS

Using comparative risk assessment models, we estimated the averted deaths, incidence, and disability-adjusted life years (DALYs) from cardiovascular disease (CVD), chronic kidney disease (CKD) and stomach cancer after implementation of (a) Australia's sodium targets (overall and by individual companies); (b) United Kingdom's targets (that covers more product categories); and (c) an optimistic scenario (sales-weighted 25th percentile sodium content for each food category included in the UK program). We used nationally representative data to estimate pre- and post-intervention sodium intake, and other key data sources from the Global Burden of Disease study. Full compliance with the Australian government's sodium targets could prevent approximately 510 deaths/year (95% UI, 335 to 757), corresponding to about 1% of CVD, CKD, and stomach cancer deaths, and prevent some 1,920 (1,274 to 2,600) new cases and 7,240 (5,138 to 10,008) DALYs/year attributable to these diseases. Over half (59%) of deaths prevented is attributed to reformulation by 5 market-dominant companies. Compliance with the UK and optimistic scenario could avert approximately an additional 660 (207 to 1,227) and 1,070 (511 to 1,856) deaths/year, respectively, compared to Australia's targets. The main limitation of this study (like other modeling studies) is that it does not prove that sodium reformulation programs will prevent deaths and disease events; rather, it provides the best quantitative estimates and the corresponding uncertainty of the potential effect of the different programs to guide the design of policies.

CONCLUSIONS

There is significant potential to strengthen Australia's sodium reformulation targets to improve its health impact. Promoting compliance by market-dominant food companies will be critical to achieving the potential health gains.

A Systematic Review of Salt Reduction Initiatives Around the World: A Midterm Evaluation of Progress Towards the 2025 Global Non-Communicable Diseases Salt Reduction Target

In 2013, the WHO recommended that all member states aim to reduce population salt intake by 30% by 2025. The year 2019 represents the midpoint, making it a critical time to assess countries' progress towards this target. This review aims to identify all national salt reduction initiatives around the world in 2019, and to quantify countries' progress in achieving the salt reduction target. Relevant data were identified through searches of peer-reviewed and gray literature, supplemented with responses from prefilled country questionnaires sent to known country leads of salt reduction or salt champions, WHO regional representatives, and international experts to request further information. Core characteristics of each country's strategy, including evaluations of program impact, were extracted and summarized. A total of 96 national salt reduction initiatives were identified, representing a 28% increase in the number reported in 2014. About 90% of the initiatives were multifaceted in approach, and 60% had a regulatory component. Approaches include interventions in settings (n= 74), food reformulation (n = 68), consumer education (n = 50), front-of-pack labeling (n = 48), and salt taxation (n = 5). Since 2014, there has been an increase in the number of countries implementing each of the approaches, except consumer education. Data on program impact were limited. There were 3 countries that reported a substantial decrease (>2 g/day), 9 that reported a moderate decrease (1-2 g/day), and 5 that reported a slight decrease (<1 g/day) in the mean salt intake over time, but none have yet met the targeted 30% relative reduction in salt intake from baseline. In summary, there has been an increase in the number of salt reduction initiatives around the world since 2014. More countries are now opting for structural or regulatory approaches. However, efforts must be urgently accelerated and replicated in other countries and more rigorous monitoring and evaluation of strategies is needed to achieve the salt reduction target.

Are there socio-demographic differences in salt behaviours and fruit and vegetable consumption in Australian adults? A nationally representative cross-sectional survey

BACKGROUND

Diets low in fruit and vegetables and high in salt are among the top dietary risk factors for non-communicable diseases (NCDs). Using a nationally representative sample of Australians, this study aimed to describe self-reported intake of fruit and vegetables, and knowledge, attitudes and behaviours related to salt intake, and determine if there were socio-demographic differences between population subgroups.

METHODS

A 2016 cross-sectional survey of Australian adults aged 18 years and over, which comprised 160 questions, including socio-demographic and health-related questions. Descriptive statistics (mean, 95% confidence interval, %) were calculated. Weighted-adjusted logistic regression models were used to determine if there were socio-demographic differences in salt behaviours and fruit and vegetable consumption.

RESULTS

A total of 1217 participants completed the survey (51% female). Less than 8% of participants reported consuming the recommended 2 or more serves of fruit and 5 or more serves of vegetables. Almost 60% of participants frequently added salt during cooking/meal preparation and 42% of respondents frequently placed a salt-shaker on the table at mealtimes. There were no consistent patterns between socio-demographic factors and measures of fruit and vegetable consumption and salt behaviours. Differences in at least one measure were found for sex, age, location, education level and weight category.

CONCLUSIONS

There were no consistent patterns between socio-demographic factors and salt behaviours and fruit and vegetable intake. Less than recommended intakes of fruit and vegetables and frequent discretionary salt use are placing Australians at risk of diet-related NCDs. Broad population-based policies and programs to improve fruit and vegetable intake and salt behaviours are needed to improve Australian's diets.

Do knowledge about sodium, health status by self-report, and having hypertension predict sodium consumption behaviors among Southern California hospital employees?

Little is known about factors that shape sodium consumption behaviors among hospital employees targeted by recent federally funded, sodium-related policy, systems, and environmental change interventions. To address this gap in health promotion practice, we assessed the influence of sodium-related knowledge and attitudes, and health status by self-report on the sodium consumption behaviors of hospital employees targeted by the Los Angeles County Sodium Reduction Initiative. Cross-sectional surveys were administered to 1,213 hospital employees at four Southern California hospitals between 2016 and 2018. Logistic regression models examined the associations between five key sodium consumption behaviors and independent variables of interest (i.e., knowledge and attitudes about sodium, self-reported general health status, and self-reported lifetime hypertension diagnosis), controlling for covariates (i.e., sociodemographic characteristics, body mass index, the type of hospital from which participants were recruited, and the median household income in the hospital's zip code). 1,213 hospital employees completed the survey (completion rate = 50%). The belief that salt intake is harmful was associated with four of five sodium consumption behaviors, while adequate sodium intake knowledge and self-reported "good health" were associated with three of the behaviors. Hypertension diagnosis was associated with only one. Understanding sodium consumption behaviors among healthcare workers can help hospitals improve their employees' health through the promotion of healthier food environments in the workplace and changes in institutional practices.

Estimation of salt intake assessed by 24-h urinary sodium level among adults speaking different dialects from the Chaoshan region of southern China

OBJECTIVE

Dietary salt intake may vary depending on different lifestyles. We aimed to estimate the different salt intakes and evaluate the knowledge and self-awareness about salt among people speaking the Teochew, Teochew-Hakka and Hakka dialects in the Chaoshan region of southern China.

DESIGN

The study followed a cluster sampling of residents in Chaoshan region. General characteristics, lifestyles, health status as well as knowledge and self-awareness related to salt intake were investigated using a questionnaire. Anthropometric variables as well as Na and K excretion in a 24-h urine collection were measured.

SETTING

Chaoshan region of China.

PARTICIPANTS

Four hundred fifteen adults who spoke only one of these three dialects.

RESULTS

The salt intake of adults who spoke the Teochew, Teochew-Hakka and Hakka dialects was 7·19 (interquartile range (IQR) 5·29-10·17), 9·03 (IQR 6·62-11·54) and 10·12 (IQR 7·61-12·82) g/d, respectively, with significant differences between Teochew and Teochew-Hakka speakers and between Teochew and Hakka speakers (both P < 0·05). The Na:K ratio for adults who spoke the three dialects was 3·00 (IQR 2·00-4·11), 3·50 (IQR 2·64-4·82) and 4·52 (IQR 3·35-5·97), respectively, and differed significantly among the groups (all P < 0·05). Multiple linear regression analysis showed increased Na:K ratio associated with hypertension (β = 0·71, P = 0·043) in Hakka speakers. Knowledge and self-awareness about salt intake were poor in this population.

CONCLUSIONS

Salt intake was closely related to lifestyles and was higher than the upper limit (5 g/d) recommended by the WHO in adults of Chaoshan, especially those speaking the Hakka dialect.

Salt added to food and body mass index: A bidirectional Mendelian randomisation study

AIM

This study aimed to determine the causal association between salt added to food and body mass index (BMI) by integrating a summary-level genome-wide association study (GWAS) data.

METHODS

We performed two-sample Mendelian randomisation (MR) analyses using summary statistics of GWAS. Inverse-variance weighted (IVW), maximum likelihood estimation, and random effect model were used to analyse the effect of salt added to food on BMI. A bidirectional MR analysis with BMI as the exposure and salt added to food as the outcome was also performed.

RESULTS

The single nucleotide polymorphisms (SNPs) were selected from the UK Biobank (n = 462 630) and a meta-analysis of 322 154 European-descent individuals. The IVW method estimate indicated that salt added to food was positively associated with BMI (β = 0.1416, SE = 0.0576, P = .0139). Results from maximum likelihood estimation (β = 0.1476, SE = 0.0363, P < .0001) and the random effect model (β = 0.1411, SE = 0.0572, P = .0137) were consistent with the IVW. Bidirectional MR analysis suggested that BMI did not causally affect salt added to food.

CONCLUSION

Our results provided qualitative evidence supporting a causal relationship between salt intake and BMI.

Sources of dietary sodium and implications for a statewide salt reduction initiative in Victoria, Australia

In Victoria, Australia, a statewide salt reduction partnership was launched in 2015. The aim was to measure Na intake, food sources of Na (level of processing, purchase origin) and discretionary salt use in a cross-section of Victorian adults prior to a salt reduction initiative. In 2016/2017, participants completed a 24-h urine collection (n 338) and a subsample completed a 24-h dietary recall (n 142). Participants were aged 41·2 (sd 13·9) years, and 56 % were females. Mean 24-h urinary excretion was 138 (95 % CI 127, 149) mmol/d for Na. Salt equivalent was 8·1 (95 % CI 7·4, 8·7) g/d, equating to about 8·9 (95 % CI 8·1, 9·6) g/d after 10 % adjustment for non-urinary losses. Mean 24-h intake estimated by diet recall was 118 (95 % CI 103, 133) mmol/d for Na (salt 6·9 (95 % CI 6·0, 7·8 g/d)). Leading dietary sources of Na were cereal-based mixed dishes (12 %), English muffins, flat/savoury/sweet breads (9 %), regular breads/rolls (9 %), gravies and savoury sauces (7 %) and processed meats (7 %). Over one-third (38 %) of Na consumed was derived from discretionary foods. Half of all Na consumed came from ultra-processed foods. Dietary Na derived from foods was obtained from retail stores (51 %), restaurants and fast-food/takeaway outlets (28 %) and fresh food markets (9 %). One-third (32 %) of participants reported adding salt at the table and 61 % added salt whilst cooking. This study revealed that salt intake was above recommended levels with diverse sources of intake. Results from this study suggest a multi-faceted salt reduction strategy focusing on the retail sector, and food reformulation would most likely benefit Victorians and has been used to inform the ongoing statewide salt reduction initiative.

The association of parents' behaviors related to salt with 24 h urinary sodium excretion of their children: A Spanish cross-sectional study

BACKGROUND

Sodium intake is excessive among Spanish children, but the salt use behaviors of parents and children are unknown. This study aims to determine behaviors related to salt intake in both schoolchildren and parents and the relationship between parental behaviors and 24 h urinary sodium excretion (UNa-24h) in children.

SUBJECTS AND METHODS

A convenience sample was taken from a cross-sectional analysis. Parents completed a self-reported questionnaire about their behaviors related to salt, and their responses were compared with the UNa-24h of their own children. The median test was used to identify differences in UNa-24h according to behaviors. Logistic regression was used to assess the relationship between the behaviors of parents and high sodium excretion in the children and the risk of children's use of table salt, adjusting for age, sex, and BMI. Multinomial logistic regression models, adjusted by the covariates, were used to study the children's salt preferences.

RESULTS

A total of 329 schoolchildren from different Spanish provinces were included in the study (mean age: 9.0 ± 1.2 years, 157 girls). The majority of families (parents mean age: 42.0 ± 5.2 years) reported adding salt to food during cooking (92%), and 59% of them never looked at the sodium content on food labels. However, none of these behaviors were related to UNa-24h (p > 0.05). The use of iodized salt (53%), the presence of a salt shaker on the table (6%), and the use of table salt by fathers (57%), mothers (52%) or children (17%) increased the odds (p < 0.05) of children having a higher UNa-24h. Checking sodium content on food labels and the use of table salt by the children or father was associated with a lower preference for salty foods (p < 0.05).

CONCLUSIONS

It is important to make parents aware of the relationship between their behaviors regarding the use of discretionary salt and their children's sodium intake. Our data suggest that salt-specific education programs on how to reduce salt both in-home and outside the home should be implemented to improve behavior skills related to salt consumption in parents and children.

Diet quality and cognitive function in mid-aged and older men and women

Background

To date much research into nutrition and cognitive function has been at the nutrient or food level, with inconsistent results. There is increasing interest in the dietary pattern approach to assess whole diet quality and its association with cognitive function. This study investigated if diet quality is associated with cognitive function in men and women aged 55 years and over.

Methods

Adults aged 55–65 years in the Wellbeing, Eating and Exercise for a Long Life (WELL) study in Victoria, Australia (n = 617) completed a postal survey including a 111-item food frequency questionnaire in 2010 and 2014. Diet quality was assessed via the revised dietary guideline index (DGI-2013) and also by its individual components which assessed key food groups and dietary behaviours from the Australian Dietary Guidelines. The Telephone Interview of Cognitive Status (TICS-m) measured cognitive function in 2014. Associations between past (2010) and recent (2014) diet quality and its components, and cognitive function were assessed by linear regression adjusted for covariates.

Results

After adjustment for age, sex, education, urban/rural status and physical activity there were no associations between diet quality in 2010 and cognitive function in 2014. However participants who reported higher dietary variety (B = 0.28, 95% CI 0.03, 0.52) and women who reported “sometimes” adding salt to food after cooking (B = 0.98, 95% CI 0.25, 1.71) in 2010 displayed better cognitive function in 2014. In 2014, usual consumption of higher fibre bread choices in the total sample (B = 1.32, 95% CI 0.42, 2.23), and higher diet quality (B = 0.03, 95% CI 0.00, 0.07) and greater fluid consumption (B = 0.14, 95% CI 0.01, 0.27) in men were all associated with better cognitive function. In addition, men who reported “usually” adding salt to their food during cooking displayed poorer cognitive function (B = -1.37, 95% CI -2.39, − 0.35). There were no other associations between dietary intake and cognitive function observed in the adjusted models.

Conclusion

An association between dietary variety and some limited dietary behaviours and cognitive function was observed, with variation by gender. Future research should consider trajectories of dietary change over longer time periods as determinants of health and function in older age.

Dietary Intake and Sources of Potassium in a Cross-Sectional Study of Australian Adults

A diet rich in potassium is important to reduce the risk of cardiovascular disease. This study assessed potassium intake; food sources of potassium (including NOVA level of processing, purchase origin of these foods); and sodium-to-potassium ratio (Na:K) in a cross-section of Australian adults. Data collection included 24-h urines (n = 338) and a 24-h diet recall (subsample n = 142). The mean (SD) age of participants was 41.2 (13.9) years and 56% were females. Mean potassium (95%CI) 24-h urinary excretion was 76.8 (73.0–80.5) mmol/day compared to 92.9 (86.6–99.1) by 24-h diet recall. Na:K was 1.9 (1.8–2.0) from the urine excretion and 1.4 (1.2–1.7) from diet recall. Foods contributing most to potassium were potatoes (8%), dairy milk (6%), dishes where cereal is the main ingredient (6%) and coffee/coffee substitutes (5%). Over half of potassium (56%) came from minimally processed foods, with 22% from processed and 22% from ultraprocessed foods. Almost two-thirds of potassium consumed was from foods purchased from food stores (58%), then food service sector (15%), and fresh food markets (13%). Overall, potassium levels were lower than recommended to reduce chronic disease risk. Multifaceted efforts are required for population-wide intervention—aimed at increasing fruit, vegetable, and other key sources of potassium intake; reducing consumption of processed foods; and working in supermarket/food service sector settings to improve the healthiness of foods available.

Self-Reported Measures of Discretionary Salt Use Accurately Estimated Sodium Intake Overall but not in Certain Subgroups of US Adults from 3 Geographic Regions in the Salt Sources Study

BACKGROUND

Excess sodium intake can increase blood pressure, and high blood pressure is a major risk factor for cardiovascular disease. Accurate population sodium intake estimates are essential for monitoring progress toward reduction, but data are limited on the amount of sodium consumed from discretionary salt.

OBJECTIVES

The aim of this study was to compare measured sodium intake from salt added at the table with that estimated according to the Healthy People 2020 (HP 2020) methodology.

METHODS

Data were analyzed from the 2014 Salt Sources Study, a cross-sectional convenience sample of 450 white, black, Asian, and Hispanic adults living in Alabama, Minnesota, and California. Sodium intake from foods and beverages was assessed for each participant through the use of 24-h dietary recalls. Estimated sodium intake from salt used at the table was assessed from self-reported frequency and estimated amounts from a previous study (HP 2020 methodology). Measured intake was assessed through the use of duplicate salt samples collected on recall days.

RESULTS

Among all study participants, estimated and measured mean sodium intakes from salt added at the table were similar, with a nonsignificant difference of 8.9 mg/d (95% CI: -36.6, 54.4 mg/d). Among participants who were non-Hispanic Asian, Hispanic, had a bachelor's degree or higher education, lived in California or Minnesota, did not report hypertension, or had normal BMI, estimated mean sodium intake was 77-153 mg/d greater than measured intake (P < 0.05). The estimated mean sodium intake was 186-300 mg/d lower than measured intake among participants who were non-Hispanic black, had a high school degree or less, or reported hypertension (P < 0.05).

CONCLUSIONS

The HP 2020 methodology for estimating sodium consumed from salt added at the table may be appropriate for the general US adult population; however, it underestimates intake in certain population subgroups, particularly non-Hispanic black, those with a high school degree or less, or those with self-reported hypertension. This study was registered at clinicaltrials.gov as NCT02474693.

Comparison of salt-related knowledge, attitudes and behaviours between parents and caregivers of children under 18 years of age and other adults who do not care for children under 18 years of age in Victoria, Australia

Background/Aims

Salt intake among Australian adults exceeds recommendations, increasing the risk of cardiovascular disease. Knowledge, attitudes and behaviours (KABs) are modifiable factors that may influence salt consumption. It is not known whether salt-related KABs among parents and caregivers of children under 18 years of age differ from other adults who do not care for children under 18 years of age. Therefore, we aimed to determine whether salt-related KABs differed between parents and caregivers and other adults. This information can be used to inform messages included in salt reduction consumer awareness campaigns.

Methods

Adults, aged 18–65 years, were recruited from four shopping centres, Facebook and a consumer research panel in the state of Victoria, Australia. Participants indicated if they were a parent or a caregiver of a child/children <18 years (‘parents/caregivers’) or not (‘other adults’). Regression models, adjusted for covariates, assessed differences in KABs between the two groups. Construct scores for KABs were developed, with high scores for knowledge indicative of high salt-related knowledge, for attitude indicative of lower importance of using salt to enhance the taste of food, and for behaviours indicative of higher frequency of engaging in behaviours to reduce salt in the diet.

Results

A total of 840 parents/caregivers and 1558 other adults completed the survey. Just over half of the parents/caregivers and other adults were female, with a mean (SD) age of 41.1 (10.3) years and 44.3 (15.3) years, respectively. Mean construct scores for salt-related KABs were similar between the two groups. Parents/caregivers were less likely to be aware of the relationship between salt and sodium (OR=0.73, p=0.002) and more likely to report difficulty in interpreting sodium information displayed on food labels (OR=1.36, p=0.004). Parents/caregivers were more likely to be concerned about a range of food-related issues, including the amount of saturated fat, sugar and salt in food. Parents/caregivers were more likely to report that they were trying to reduce their salt intake (OR=1.27, p=0.012) and more likely to report adding salt at the table (OR=1.28, p=0.008).

Conclusions

There were some differences in salt-related KABs between parents/caregivers and other adults. These findings provide insight into particular messages that could be focused on in consumer awareness campaigns that seek to improve parents’/caregivers’ KABs related to salt intake. Specifically, messages targeted at parents/caregivers should include practical guidance to reduce table salt and resources to assist in interpreting sodium information on food labels and the relationship of sodium to salt.

Knowledge, attitudes, and practices related to salt consumption in Nepal: Findings from the community-based management of non-communicable diseases project in Nepal (COBIN)

High salt/sodium intake is associated with an increased risk of hypertension, which is a major risk factor for cardiovascular diseases. This paper aims to examine the association between salt consumption and salt-related knowledge, attitudes, and practices (KAP) in Nepal. The cross-sectional data used in this study were collected as part of the community-based management of non-communicable diseases project (COBIN) to understand the amount and KAP related to salt consumption in Nepal. Multivariate hierarchical logistic regression was performed to assess the association of salt-related KAP and determinants of high salt consumption in Nepal. The mean per capita salt intake was 8.0 (±3.7) g/day, with 81.6% of the population reporting higher intake than the WHO recommendation of <5 g/day. People of upper castes [adjusted odds ratio (aOR) = 0.7; 95% confidence interval (CI): 0.5-0.9], people in large families (aOR = 0.6; 95% CI: 0.5-0.7), respondents who were advised to lower salt intake (aOR = 0.6; 95% CI: 0.4-0.9) and who checked salt/sodium labels in food (aOR = 0.6; 95% CI: 0.4-0.9) were less likely to consume higher amounts of salt. Similarly, people who added extra salt to their food at the table (aOR = 1.4; 95 CI: 1.1-1.9) and who reported consuming high amounts of salt (aOR = 1.5; 95% CI: 1.1-2.3) were more likely to have high salt intake. High salt intake was documented in this population. This study suggests the need for culturally tailored community-based behavior modification through health education and dietary counseling to effectively reduce salt consumption and thereby support a reduction in hypertension and cardiovascular diseases in Nepal.

Salt consumption by Australian adults: a systematic review and meta-analysis

OBJECTIVE

Salt reduction is a public health priority because it is a leading contributor to the global burden of disease. As in Australia there is uncertainty about the current level of salt intake, we sought to estimate current levels.

STUDY DESIGN

Random effects meta-analysis of data from 31 published studies and one unpublished dataset that reported salt or sodium consumption by Australian adults on the basis of 24-hour urine collections or dietary questionnaires.

DATA SOURCES

MEDLINE (via Ovid) and EMBASE (to August 2016).

DATA SYNTHESIS

Thirty-one published studies and one unpublished dataset (1989-2015; 16 836 individuals) were identified. The mean weighted salt consumption estimated from 24-hour urine collections was 8.70 g/day (95% CI, 8.39-9.02 g/day); after adjusting for non-urinary salt excretion, the best estimate of salt intake in Australia is 9.6 g/day. The mean weighted intake was 10.1 g/day (95% CI, 9.68-10.5 g/day) for men and 7.34 g/day (95% CI, 6.98-7.70 g/day) for women. Mean weighted consumption was 6.49 g/day (95% CI, 5.94-7.03 g/day) when measured with diet diaries, 6.76 g/day (95% CI, 5.48-8.05 g/day) when assessed with food frequency questionnaires, and 6.73 g/day (95% CI, 6.34-7.11) when assessed by dietary recall. Salt intake had not decreased between 1989 and 2015 (R² = -0.02; P = 0.36).

CONCLUSION

Salt intake in Australian adults exceeds the WHO-recommended maximum of 5 g/day and does not appear to be declining. Measuring salt intake with methods based on self-reporting can substantially underestimate consumption. The data highlight the need for ongoing action to reduce salt consumption in Australia and robust monitoring of population salt intake.

Dietary sources of salt intake in adults and older people: a population-based study in a Brazilian town

OBJECTIVE

To assess salt intake and its dietary sources using biochemical and self-report methods and to characterize salt intake according to sociodemographic and disease-related variables in a sample of the Brazilian population.

DESIGN

Population-based cross-sectional survey.

SETTING

Salt intake was assessed by biochemical (24 h urinary Na excretion) and self-report methods (sodium FFQ, 24 h dietary recall, seasoned-salt questionnaire, discretionary-salt questionnaire and total reported salt intake).ParticipantsAdults and older people (n 517) aged 20-80 years, living in Artur Nogueira, São Paulo, Brazil.

RESULTS

Mean salt intake based on 24 h urinary Na excretion and total reported salt intake was 10·5 and 11·0 g/d, respectively; both measures were significantly correlated. Discretionary salt and seasoned salt were the most important sources of salt intake (68·2 %). Men in the study consumed more salt than women as estimated by 24 h urinary Na excretion (11·7 v. 9·6 g salt/d; P&lt;0·0001). Participants known to be hypertensive added more salt to their meals but consumed less salty ultra-processed foods. Waist circumference in both sexes and BMI were positively correlated with salt intake estimated by 24 h urinary Na excretion. In addition, regression analysis revealed that being a young male or having a high waist circumference was a predictor of higher salt intake.

CONCLUSIONS

Salt intake in this population was well above the recommended amount. The main source of salt intake came from salt added during cooking. Salt intake varied according to sex and waist circumference.

Salt intake and dietary sources of salt on weekdays and weekend days in Australian adults

OBJECTIVE

To assess if there is a difference in salt intake (24 h urine collection and dietary recall) and dietary sources of salt (Na) on weekdays and weekend days.

DESIGN

A cross-sectional study of adults who provided one 24 h urine collection and one telephone-administered 24 h dietary recall.

SETTING

Community-dwelling adults living in the State of Victoria, Australia.

SUBJECTS

Adults (n 598) who participated in a health survey (53·5 % women; mean age 57·1 (95 % CI 56·2, 58·1) years).

RESULTS

Mean (95 % CI) salt intake (dietary recall) was 6·8 (6·6, 7·1) g/d and 24 h urinary salt excretion was 8·1 (7·8, 8·3) g/d. Mean dietary and 24 h urinary salt (age-adjusted) were 0·9 (0·1, 1·6) g/d (P=0·024) and 0·8 (0·3, 1·6) g/d (P=0·0017), respectively, higher at weekends compared with weekdays. There was an indication of a greater energy intake at weekends (+0·6 (0·02, 1·2) MJ/d, P=0·06), but no difference in Na density (weekday: 291 (279, 304) mg/MJ; weekend: 304 (281, 327) mg/MJ; P=0·360). Cereals/cereal products and dishes, meat, poultry, milk products and gravy/sauces accounted for 71 % of dietary Na.

CONCLUSIONS

Mean salt intake (24 h urine collection) was more than 60 % above the recommended level of 5 g salt/d and 8-14 % more salt was consumed at weekends than on weekdays. Substantial reductions in the Na content of staple foods, processed meat, sauces, mixed dishes (e.g. pasta), convenience and takeaway foods are required to achieve a significant consistent reduction in population salt intake throughout the week.

Protocol for the Process Evaluation of a Complex, Statewide Intervention to Reduce Salt Intake in Victoria, Australia

Systematic reviews of trials consistently demonstrate that reducing salt intake lowers blood pressure. However, there is limited evidence on how interventions function in the real world to achieve sustained population-wide salt reduction. Process evaluations are crucial for understanding how and why an intervention resulted in its observed effect in that setting, particularly for complex interventions. This project presents the detailed protocol for a process evaluation of a statewide strategy to lower salt intake in Victoria, Australia. We describe the pragmatic methods used to collect and analyse data on six process evaluation dimensions: reach, dose or adoption, fidelity, effectiveness, context and cost, informed by Linnan and Steckler's framework and RE-AIM. Data collection methods include routinely collected administrative data; surveys of processed foods, the population, food industry and organizations; targeted campaign evaluation and semi-structured interviews. Quantitative and qualitative data will be triangulated to provide validation or context for one another. This process evaluation will contribute new knowledge about what components of the intervention are important to salt reduction strategies and how the interventions cause reduced salt intake, to inform the transferability of the program to other Australian states and territories. This protocol can be adapted for other population-based, complex, disease prevention interventions.

Estimating mean change in population salt intake using spot urine samples

Background

Spot urine samples are easier to collect than 24-h urine samples and have been used with estimating equations to derive the mean daily salt intake of a population. Whether equations using data from spot urine samples can also be used to estimate change in mean daily population salt intake over time is unknown. We compared estimates of change in mean daily population salt intake based upon 24-h urine collections with estimates derived using equations based on spot urine samples.

Methods

Paired and unpaired 24-h urine samples and spot urine samples were collected from individuals in two Australian populations, in 2011 and 2014. Estimates of change in daily mean population salt intake between 2011 and 2014 were obtained directly from the 24-h urine samples and by applying established estimating equations (Kawasaki, Tanaka, Mage, Toft, INTERSALT) to the data from spot urine samples. Differences between 2011 and 2014 were calculated using mixed models.

Results

A total of 1000 participants provided a 24-h urine sample and a spot urine sample in 2011, and 1012 did so in 2014 (paired samples n = 870; unpaired samples n = 1142). The participants were community-dwelling individuals living in the State of Victoria or the town of Lithgow in the State of New South Wales, Australia, with a mean age of 55 years in 2011. The mean (95% confidence interval) difference in population salt intake between 2011 and 2014 determined from the 24-h urine samples was -0.48g/day (-0.74 to -0.21; P < 0.001). The corresponding result estimated from the spot urine samples was -0.24 g/day (-0.42 to -0.06; P = 0.01) using the Tanaka equation, -0.42 g/day (-0.70 to -0.13; p = 0.004) using the Kawasaki equation, -0.51 g/day (-1.00 to -0.01; P = 0.046) using the Mage equation, -0.26 g/day (-0.42 to -0.10; P = 0.001) using the Toft equation, -0.20 g/day (-0.32 to -0.09; P = 0.001) using the INTERSALT equation and -0.27 g/day (-0.39 to -0.15; P < 0.001) using the INTERSALT equation with potassium. There was no evidence that the changes detected by the 24-h collections and estimating equations were different (all P > 0.058). Separate analysis of the unpaired and paired data showed that detection of change by the estimating equations was observed only in the paired data.

Conclusions

All the estimating equations based upon spot urine samples identified a similar change in daily salt intake to that detected by the 24-h urine samples. Methods based upon spot urine samples may provide an approach to measuring change in mean population salt intake, although further investigation in larger and more diverse population groups is required.

The technical report on sodium intake and cardiovascular disease in low- and middle-income countries by the joint working group of the World Heart Federation, the European Society of Hypertension and the European Public Health Association

Ingestion of sodium is essential to health, but excess sodium intake is a risk factor for hypertension and cardiovascular disease. Defining an optimal range of sodium intake in populations has been challenging and controversial. Clinical trials evaluating the effect of sodium reduction on blood pressure have shown blood pressure lowering effects down to sodium intake of less than 1.5 g/day. Findings from these blood pressure trials form the basis for current guideline recommendations to reduce sodium intake to less than 2.3 g/day. However, these clinical trials employed interventions that are not feasible for population-wide implementation (i.e. feeding studies or intensive behavioural interventions), particularly in low and middle-income countries. Prospective cohort studies have identified the optimal range of sodium intake to reside in the moderate range (3-5 g/day), where the risk of cardiovascular disease and death is lowest. Therefore, there is consistent evidence from clinical trials and observational studies to support reducing sodium intake to less than 5 g/day in populations, but inconsistent evidence for further reductions below a moderate intake range (3-5 g/day). Unfortunately, there are no large randomized controlled trials comparing low sodium intake (< 3 g/day) to moderate sodium intake (3-5 g/day) in general populations to determine the net clinical effects of low sodium intake. Until such trials are completed, it is likely that controversy about optimal sodium intake range will continue. This working group calls for the completion of large definitive clinical trials to clarify the range of sodium intake for optimal cardiovascular health within the moderate to low intake range. We support interventions to reduce sodium intake in populations who consume high sodium intake (> 5 g/day), which should be embedded within an overall healthy dietary pattern.

The Science of Salt: A focused review on salt-related knowledge, attitudes and behaviors, and gender differences

The aim of the current review was to examine the scope of studies published in the Science of Salt Weekly that contained a measure of self-reported knowledge, attitudes, and behavior (KAB) concerning salt. Specific objectives were to examine how KAB measures are used to evaluate salt reduction intervention studies, the questionnaires used, and whether any gender differences exist in self-reported KAB. Studies were reviewed from the commencement of Science of Salt Weekly, June 2013 to the end of August 2017. Seventy-five studies had relevant measures of KAB and were included in this review, 13 of these were salt-reduction intervention-evaluation studies, with the remainder (62) being descriptive KAB studies. The KAB questionnaires used were specific to the populations studied, without evidence of a best practice measure. 40% of studies used KAB alone as the primary outcome measure; the remaining studies used more quantitative measures of salt intake such as 24-hour urine. Only half of the descriptive studies showed KAB outcomes disaggregated by gender, and of those, 73% showed women had more favorable KAB related to salt. None of the salt intervention-evaluation studies showed disaggregated KAB data. Therefore, it is likely important that evaluation studies disaggregate, and are appropriately powered to disaggregate all outcomes by gender to address potential disparities.

Collecting Evidence to Inform Salt Reduction Policies in Argentina: Identifying Sources of Sodium Intake in Adults from a Population-Based Sample

The maximum content of sodium in selected processed foods (PF) in Argentina was limited by a law enacted in 2013. Data about intake of these and other foods are necessary for policy planning, implementation, evaluation, and monitoring. We examined data from the CESCAS I population-based cohort study to assess the main dietary sources among PF and frequency of discretionary salt use by sex, age, and education attainment, before full implementation of the regulations in 2015. We used a validated 34-item FFQ (Food Frequency Questionnaire) to assess PF intake and discretional salt use. Among 2127 adults in two Argentinean cities, aged 35-76 years, mean salt intake from selected PFs was 4.7 g/day, higher among male and low education subgroups. Categories of foods with regulated maximum limits provided near half of the sodium intake from PFs. Use of salt (always/often) at the table and during cooking was reported by 9% and 73% of the population, respectively, with higher proportions among young people. Reducing salt consumption to the target of 5 g/day may require adjustments to the current regulation (reducing targets, including other food categories), as well as reinforcing strategies such as education campaigns, labeling, and voluntary agreement with bakeries.

Knowledge, attitudes and behaviours related to dietary salt among adults in the state of Victoria, Australia 2015

Background

Information on consumer’s knowledge, attitudes and behaviours (KABs) related to salt can be used to inform awareness and education campaigns and serve as a baseline measure to monitor changes in KABs over time. The aim of this study was to determine KABs related to salt intake among Victorian adults.

Methods

Cross-sectional survey conducted in Victorian adults aged 18–65 years. Participants were recruited from shopping centres located in Melbourne and Geelong and via online methods (Facebook and Consumer Research Panel) to complete an online survey assessing KABs related to dietary salt. Descriptive statistics (mean (SD) or n (%)) were used to report survey findings.

Results

A total of 2398 participants provided a valid survey (mean age 43 years (SD 13), 57% female). The majority (80%) were born in Australia and 63% were the main household grocery shopper. The majority (89%) were aware of the health risks associated with a high salt intake. Eighty three percent believed that Australians eat too much salt. Three quarters (75%) correctly identified salt from processed foods as being the main source of salt in the diet. Less than a third (29%) of participants believed their own individual salt intake exceeded dietary recommendations and only 28% could correctly identify the maximum recommended daily intake for salt. Just under half (46%) of participants were concerned about the amount of salt in food. Almost two thirds (61%) of participants believed that there should be laws which limit the amount of salt added to manufactured foods and 58% agreed that it was difficult to find lower salt options when eating out.

Conclusions

The findings of this study serve as a baseline assessment of KABs related to salt intake in Victorian adults and can be used to assess changes in salt related KABs over time. Public concern about salt is low as many people remain unaware of their own salt intake. An increased awareness of the excessive amount of salt consumed and increased availability of lower salt foods are likely to reduce population salt intake.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4451-0) contains supplementary material, which is available to authorized users.

Dietary salt intake in the Australian population

Objective

To update the estimate of mean salt intake for the Australian population made by the Australian Health Survey (AHS).

Design

A secondary analysis of the data collected in a cross-sectional survey was conducted. Estimates of salt intake were made in Lithgow using the 24 h diet recall methodology employed by the AHS as well as using 24 h urine collections. The data from the Lithgow sample were age- and sex-weighted, to provide estimates of daily salt intake for the Australian population based upon (i) the diet recall data and (ii) the 24 h urine samples.

Setting

Lithgow, New South Wales, Australia.

Subjects

Individuals aged ≥20 years residing in Lithgow and listed on the 2009 federal electoral roll.

Results

Mean (95 % CI) salt intake estimated from the 24 h diet recalls was 6·4 (6·2, 6·7) g/d for the Lithgow population compared with a corresponding figure of 6·2 g/d for the Australian population derived from the AHS. The corresponding estimate of salt intake for Lithgow adults based upon the 24 h urine collections was 9·0 (8·6, 9·4) g/d. When the age- and sex-specific estimates of salt intake obtained from the 24 h urine collections in the Lithgow sample were weighted using Australian census data, estimated salt intake for the Australian population was 9·0 (8·6, 9·5) g/d. Further adjustment for non-urinary Na excretion made the best estimate of daily salt intake for both Lithgow and Australia about 9·9 g/d.

Conclusions

The dietary recall method used by the AHS likely substantially underestimated mean population salt consumption in Australia.

Socioeconomic Determinants of Sodium Intake in Adult Populations of High-Income Countries: A Systematic Review and Meta-Analysis

BACKGROUND

A poorer quality diet among individuals with low socioeconomic status (SES) may partly explain the higher burden of noncommunicable disease among disadvantaged populations. Because there is a link between sodium intake and noncommunicable diseases, we systematically reviewed the current evidence on the social patterning of sodium intake.

OBJECTIVES

To conduct a systematic review and a meta-analysis of the evidence on the association between SES and sodium intake in healthy adult populations of high-income countries.

SEARCH METHODS

We followed the PRISMA-Equity guidelines in conducting a literature search that ended June 3, 2016, via MEDLINE, Embase, and SciELO. We imposed no publication date limits.

SELECTION CRITERIA

We considered only peer-reviewed articles meeting the following inclusion criteria: (1) reported a measure of sodium intake disaggregated by at least 1 measure of SES (education, income, occupation, or any other socioeconomic indicator); (2) were written in English, Spanish, Portuguese, French, or Italian; and (3) were conducted in a high-income country as defined by the World Bank (i.e., per capita national gross income was higher than $12 746). We also excluded articles that exclusively sampled low-SES individuals, pregnant women, children, adolescents, elderly participants, or diseased patients or that reported results from a trial or intervention.

DATA COLLECTION AND ANALYSIS

As summary measures, we extracted (1) the direction (positive, negative, or neutral) and the magnitude of the association between each SES indicator and sodium intake, and (2) the estimated sodium intake according to SES level. When possible and if previously unreported, we calculated the magnitude of the relative difference in sodium intake between high- and low-SES groups for each article, applying this formula: ([value for high-SES group - value for low-SES group]/[value for high-SES group]) × 100. We considered an association significant if reported as such, and we set an arbitrary 10% relative difference as clinically relevant and significant. We conducted a meta-analysis of the relative difference in sodium intake between high- and low-SES groups. We included articles in the meta-analysis if they reported urine-based sodium estimates and provided the total participant numbers in the low- and high-SES groups, the estimated sodium intake means for each group (in mg/day or convertible units), and the SDs (or transformable measures). We chose a random-effects model to account for both within-study and between-study variance.

MAIN RESULTS

Fifty-one articles covering 19 high-income countries met our inclusion criteria. Of these, 22 used urine-based methods to assess sodium intake, and 30 used dietary surveys. These articles assessed 171 associations between SES and sodium intake. Among urine-based estimates, 67% were negative (higher sodium intake in people of low SES), 3% positive, and 30% neutral. Among diet-based estimates, 41% were negative, 21% positive, and 38% neutral. The random-effects model indicated a 14% relative difference between low- and high-SES groups (95% confidence interval [CI] = -18, -9), corresponding to a global 503 milligrams per day (95% CI = 461, 545) of higher sodium intake among people of low SES.

CONCLUSIONS

People of low SES consume more sodium than do people of high SES, confirming the current evidence on socioeconomic disparities in diet, which may influence the disproportionate noncommunicable disease burden among disadvantaged socioeconomic groups. Public Health Implications. It is necessary to focus on disadvantaged populations to achieve an equitable reduction in sodium intake to a population mean of 2 grams per day as part of the World Health Organization's target to achieve a 25% relative reduction in noncommunicable disease mortality by 2025.

Dietary Intake and Sources of Potassium and the Relationship to Dietary Sodium in a Sample of Australian Pre-School Children

The aim of this study was to determine the intake and food sources of potassium and the molar sodium:potassium (Na:K) ratio in a sample of Australian pre-school children. Mothers provided dietary recalls of their 3.5 years old children (previous participants of Melbourne Infant Feeding Activity and Nutrition Trial). The average daily potassium intake, the contribution of food groups to daily potassium intake, the Na:K ratio, and daily serves of fruit, dairy, and vegetables, were assessed via three unscheduled 24 h dietary recalls. The sample included 251 Australian children (125 male), mean age 3.5 (0.19) (SD) years. Mean potassium intake was 1618 (267) mg/day, the Na:K ratio was 1.47 (0.5) and 54% of children did not meet the Australian recommended adequate intake (AI) of 2000 mg/day for potassium. Main food sources of potassium were milk (27%), fruit (19%), and vegetable (14%) products/dishes. Food groups with the highest Na:K ratio were processed meats (7.8), white bread/rolls (6.0), and savoury sauces and condiments (5.4). Children had a mean intake of 1.4 (0.75) serves of fruit, 1.4 (0.72) dairy, and 0.52 (0.32) serves of vegetables per day. The majority of children had potassium intakes below the recommended AI. The Na:K ratio exceeded the recommended level of 1 and the average intake of vegetables was 2 serves/day below the recommended 2.5 serves/day and only 20% of recommended intake. An increase in vegetable consumption in pre-school children is recommended to increase dietary potassium and has the potential to decrease the Na:K ratio which is likely to have long-term health benefits.

Effectiveness of a Communication for Behavioral Impact (COMBI) Intervention to Reduce Salt Intake in a Vietnamese Province Based on Estimations From Spot Urine Samples

This study evaluated the effectiveness of the Communication for Behavioral Impact (COMBI)–Eat Less Salt intervention conducted in Viet Tri, Vietnam. The behavior change intervention was implemented in four wards and four communes for one year, which included mass media communication, school interventions, community programs, and focus on high‐risk groups. Mean sodium excretion was estimated from spot urine samples using different equations. A subsample provided 24‐hour urine to validate estimates from spot urine. Information about salt‐related knowledge and behaviors was also collected. There were 513 participants at both baseline and follow‐up. Mean sodium excretion estimated from spot urines fell significantly from 8.48 g/d at baseline to 8.05 g/d at follow‐up (P=.001). All spot equations demonstrated a significant reduction in sodium levels; however, the change was smaller than the measured 24‐hour urine. Participants showed improved knowledge and behaviors following the intervention. The COMBI intervention was effective in lowering average population salt intake and improving knowledge and behaviors.

Effects of a community-based salt reduction program in a regional Australian population

Background

Salt reduction is a public health priority but there are few studies testing the efficacy of plausible salt reduction programs.

Methods

A multi-faceted, community-based salt reduction program using the Communication for Behavioral Impact framework was implemented in Lithgow, Australia. Single 24-h urine samples were obtained from 419 individuals at baseline (2011) and from 572 at follow-up (2014). Information about knowledge and behaviors relating to salt was also collected.

Results

Survey participants were on average 56 years old and 58 % female. Mean salt intake estimated from 24-h urine samples fell from 8.8 g/day (SD = 3.6 g/day) in 2011 to 8.0 (3.6) g/day in 2014 (−0.80, 95 % confidence interval −1.2 to −0.3;p < 0.001). There were significant increases in the proportion of participants that knew the recommended upper limit of salt intake (18 % vs. 29 %; p < 0.001), knew the importance of salt reduction (64 % vs. 78 %; p < 0.001) and reported changing their behaviors to reduce their salt intake by using spices (5 % vs. 28 %; p < 0.001) and avoiding eating out (21 % vs. 34 %; p < 0.001). However, the proportions that checked food labels (30 % vs. 25 %; p = 0.02) fell, as did the numbers avoiding processed foods (44 % vs. 35 %; p = 0.006). Twenty-six percent reported using salt substitute at the end of the intervention period and 90 % had heard about the program. Findings were robust to multivariable adjustment.

Conclusions

Implementation of this multi-faceted community-based program was associated with a ~10 % reduction in salt consumption in an Australian regional town. These findings highlight the potential of well-designed health promotion programs to compliment other population-based strategies to bring about much-needed reductions in salt consumption.

Clinical trial registration

NCT02105727.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3064-3) contains supplementary material, which is available to authorized users.