Narrative Review of Hydration and Selected Health Outcomes in the General Population

The Impact of a Commercial Electrolyte Beverage on the Hydration Status of Active Men and Women

BACKGROUND/OBJECTIVES

Hypo-hydration is a major health concern that affects performance and is associated with increasing morbidity and growing health care costs. There is an emerging interest in optimizing hydration and identifying how factors such as ingestion rate and beverage composition affect hydration. This study examined three beverages with varying ingestion rates and measured markers of hydration.

METHODS

Thirty healthy, active participants between the ages of 18 and 45 years were given three different beverages on three separate days. The beverages were of identical volumes (1 L), but differed in the rate of ingestion, carbohydrate content and electrolyte content. Beverage 1 and water alone were both consumed at a metered rate of one liter over four hours, whereas Beverage 2 was used as a positive control and was consumed at a bolus rate of one liter in 30 min.

RESULTS

After six hours, Beverage 1 significantly improved markers of hydration compared to water alone or Beverage 2. Beverage 1 decreased cumulative urine output vs. water alone by 32% (absolute difference -0.33 L; CI ± -0.16 to -0.51) and vs. Beverage 2 by 26% (absolute difference -0.26 L; CI ± -0.13 to -0.38). Beverage 1 increased the beverage hydration index vs. water alone by 64% (absolute difference +0.64 L; CI ± 0.36 to 0.92) and vs. Beverage 2 by 48% (absolute difference +0.53 L; CI ± 0.30 to 0.76).

CONCLUSIONS

Beverage 1 is superior to water alone at improving hydration when it is ingested at similar rates. Moreover, metered ingestion of Beverage 1 improved hydration compared to a bolus ingestion of Beverage 2, this could be due to the dissimilar ingestion rates and/or beverage composition.

Vitamin D and its relationship to performance and health during a competitive period in elite women's basketball and volleyball players

Vitamin D [25(OH)D] is a key nutrient, although its level is often low in the general population. To investigate the relationship between vitamin D levels and muscle performance, and to analyze how vitamin D changes during a 16-week competitive season and its relationship to the performance tests performed. Participant characteristics: age 25.1 ± 4.7 years; height 1.8 ± 0.1 m, and body mass 73.9 ± 15.4 kg. Vitamin D levels (ng/mL) were at T1 (September): 33.7 ± 14.7 (n = 23), and at T2 (January): 26.1 ± 7.3 (n = 23). Over 16 weeks of competition, participants' blood was analyzed to determine their vitamin D levels. Their athletic abilities were evaluated through various tests: vertical jumps (standing jump and countermovement jump); 20-m sprint without direction changes; and intermittent endurance test; the vitamin D level decreased from T1 to T2 by -22. 40% [p < 0.05] but performance improved in all tests performed (SJ: 4.57%; CMJ: 6.94%; VO2max: 4.99% [p < 0.05]; 20 m: -1.83%). There is a relationship between vitamin D levels and physical performance in female indoor athletes. The results suggest that increased training load may also negatively affect vitamin D levels in elite female indoor athletes.

The Association of moisture intake and constipation among us adults: evidence from NHANES 2005-2010

BACKGROUND

Constipation is a common gastrointestinal disorder that affects the quality of life of millions of adults worldwide. Dietary moisture intake is considered to have a significant impact on intestinal health, yet its specific role in constipation has not been thoroughly investigated in large-scale population studies. This study aims to explore the correlation between adult dietary moisture intake and constipation by analyzing the NHANES database, filling a knowledge gap in the literature.

METHODS

Data from NHANES participants aged 20 years and older from 2005 to 2010 were analyzed. Moisture intake was assessed using dietary recall data, which included moisture from all food and beverages consumed. A weighted logistic regression model was used to assess the relationship between moisture intake and the risk of constipation, calculating the odds ratios (ORs) and their 95% confidence intervals (CIs), while controlling for potential confounders. Additionally, restricted cubic splines (RCS) were applied to further explore potential non-linear patterns in the relationship between moisture intake and constipation, along with subgroup analysis.

RESULTS

The study included 14,492 participants, of whom 1,514 reported constipation issues. After adequately adjusting for confounders, a significant negative correlation was observed between moisture intake and constipation risk (OR 0.81; 95% CI: 0.74-0.89). Quartile analysis of moisture intake demonstrated that, compared to the first quartile Q1 (0.06 to 1.90 kg), the constipation risk for the second quartile Q2 (1.91 to 2.53 kg), third quartile Q3 (2.54 to 3.36 kg), and fourth quartile Q4 (3.37 to 16.97 kg) were OR 0.80 (95% CI: 0.64-0.72), OR 0.57 (95% CI: 0.45-0.72), and OR 0.54 (95% CI: 0.44-0.67) respectively, with a trend test P-value ofless than 0.001. RCS regression revealed a significant non-linear negative relationship between moisture intake and constipation prevalence (P < 0.001). Depression may modulate the relationship between moisture and constipation (interaction effect P = 0.014).

CONCLUSION

The findings of this study indicate that appropriate dietary moisture intake is significantly associated with a lower risk of constipation, demonstrating a dose-response relationship. This emphasizes the importance of considering adequate moisture intake in the prevention and management of constipation. Future studies should adopt a prospective design to further verify the causal relationship between dietary moisture intake and constipation progression.

Identifying and managing fatigue in nurses completing on-call work

Specialist nurses working in Therapeutic Apheresis Services (TAS) at NHS Blood and Transplant participate in an on-call rota. This means working above and beyond their rostered hours and can lead to them working 24 hours in one period. There is a noted risk of fatigue for people who work more than 13 hours in one stretch, and therefore it is important to understand how to recognise and manage the signs of fatigue. A literature review was performed to understand fatigue in various industries and how this was managed. This was then coupled with TAS internal data collection, exit interview data and sickness data to inform the design of a Fatigue Identification Questionnaire filled out by nurses during on-call working. Due to the strong link between fatigue and the hours worked, it is recommended that further work is undertaken to implement fatigue-management processes.

Hydration Habits and Water Balance in a Working Population in Greece

BACKGROUND/OBJECTIVES

Adequate hydration is fundamental for maintaining physical and mental health, yet dehydration remains a common issue, with significant health consequences such as fatigue, impaired cognitive function, and increased risk of chronic diseases. This study aimed to assess the water balance status of healthy employees in Greece and explore the influence of sociodemographic, anthropometric, occupational, and other lifestyle factors.

METHODS

After completing a validated questionnaire, demographic, dietary, and occupational factors were first analyzed by gender and then examined for their association with water balance, defined as the net difference between water intake and losses, using univariate and multivariable analyses.

RESULTS

Daily water consumption had a median value of 3063.77 mL (Q1: 2181.62, Q3: 4070.04), with men consuming significantly more than women. Multivariable analysis identified several factors associated with water balance, including years of education (β: -21.88, SE: 8.55), hours of work per week (β: 30.17, SE: 15.38), use of glasses during the day (Yes vs. No: β: 423.13, SE: 216.41), use of a bottle during the day (Yes vs. No: β: 873.50, SE: 278.82), and consuming water for pleasure (Yes vs. No: β: 478.63, SE: 200.16). Additionally, exposure to weather conditions at work (Yes vs. No) was suggested to have a positive influence on water balance.

CONCLUSIONS

This study underscores the complex interplay between sociodemographic and occupational factors and hydration practices, providing evidence for targeted hydration strategies, as wellness programs and public health initiatives aimed at improving hydration among working populations in Greece.

What predicts the initial interest and uptake of health behaviours? An exploratory study to understand commitment and early success through a simple behaviour

Extant models of health behaviour change often overlook stages in which individuals decide to partake in interventions. The current study aimed to identify behavioural and psychological factors that could capture a person's readiness to change a health behaviour and whether these could predict progression through stages of commitment. Rather than explicitly advertising a health behaviour intervention, we invited individuals to partake in a general health behaviour survey using a paid advertising campaign on Facebook (Phase 1). Interested participants completed questionnaires assessing habitual water intake, other health behaviours and several behavioural and psychological variables. Those who met the eligibility criteria for low daily water intake (N = 977) were invited to participate in a behaviour change challenge to increase water intake over 4 weeks (Phase 2). Additional online surveys were completed at baseline, week 2, and week 4 of the challenge with water intake assessed again at week 4. Participants were categorised into 7 groups based on expressed interest in participating, reasons for not wanting to participate, perceived current success with water intake, and their level of improvement during the challenge. Factor analysis of the behavioural and psychological variables identified four latent factors. We labelled these factors as Good Resources, Health Orientation, Driven Type, and Positive Energy. Through general linear modelling, we observed that the first three of these factors was associated with interest and whether participants increased their water intake. Assessment based on these factors could be useful for personalising health behaviour interventions to target individuals based on their readiness to change health behaviours.

[Hydration and natural mineral water: a review on the importance of water and mineral intake for health]

The aim of this review is to highlight the properties of water and the need for adequate hydration for the proper functioning of the body. Spanish and European legislation on natural mineral waters has been reviewed, as well as the consensus documents of national and international congresses on hydration. In addition, relevant articles and, in particular, reviews on hydration and health, as well as other adapted terms of interest for each of the sections of this manuscript have been included. The total daily adequate amount of water recommended by EFSA for adults is between 2.0-2.5 liters, depending on gender and it should be adapted to each person's physiological situation and individual state of health. Water is an essential nutrient that helps maintaining normal physical and cognitive functions of the body. The mineralogical composition of natural mineral waters is important and can have health benefits depending on the needs of each individual.

Impact of associated factors and adherence to Mediterranean diet on insomnia among Arab men living in Jordan

The detrimental health and economic burdens associated with insomnia have led to investigations examining its prevalence and potential predictors to utilize this information in insomnia prevention/treatment. Ethnicity, gender, and lifestyle habits are among the important predictors associated with insomnia. The aim of this study was to examine the prevalence of insomnia and potential predictors of insomnia among Arab men living in Jordan, including Mediterranean diet (MD) adherence. The inclusion criteria of this cross-sectional, correlational study were: (1) being a male; (2) aged 18 and older; and (3) able to read, write, and speak the Arabic language. Online questionnaires were used to assess participants' sociodemographic information, adherence to the MD, physical activity, and insomnia. Results demonstrated that there was a high prevalence of insomnia (53.9%) among the study's participants (N = 529). Moreover, in the unadjusted model, the study revealed that being unemployed (OR = 1.90, p = 0.018), categorized as dehydrated (OR = 1.20, p = 0.020), overweight (OR = 1.30, p = 0.035), sleeping less than 6 hours/day (OR = 2.10, p < 0.001), and having high adherence to the MD (OR = 1.60, p = 0.010) were predictors of insomnia. Meanwhile, the adjusted multivariate logistic regression model indicated that being married (OR = 1.20, p = 0.020) played a significant protective role against developing insomnia among Arab men. While high adherence to MD (OR = 1.642, p = 0.028) and sleeping less than 6 hours/day (OR = 2.760, p < 0.001) were relative risk factors for experiencing insomnia. The high prevalence of insomnia in this population and the identification of possible predictors associated with insomnia, and the unexpected relationship between adherence to the MD and insomnia warrant further in-depth investigations that may help promote the understanding of the factors associated with insomnia and facilitate the development of interventions to target it.

Association between hydration status and the risk and all-cause mortality of diabetic kidney disease

BACKGROUND

This cohort study aimed to explore the relationship between hydration status and the risk of diabetic kidney disease (DKD) as well as all-cause death in DKD patients.

METHODS

Weighted univariable and multivariable logistic regression models were used to explore the association between hydration status and DKD risk in diabetic population while weighted univariable and multivariable Cox regression models were used to identify the association between hydration status and all-cause mortality in DKD patients. Kaplan-Meier curve was plotted to present the survival probability of patients with different hydration status. Estimates were presented as odds ratio (OR), and hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

The mean follow-up time was 79.74 (±1.89) months. There were 2041 participants with DKD, and 2889 participants without. At the end of the follow-up, 965 participants were alive. The risk of DKD was increased as the increase of osmolarity level (OR = 1.07, 95%CI: 1.05-1.08). The elevated risk of DKD was observed in patients with impending dehydration (OR = 1.49, 95%CI: 1.19-1.85) or current dehydration (OR = 2.69, 95%CI: 2.09-3.46). The association between increased osmolarty level and elevated risk of all-cause mortality in DKD patients was statistically different (HR = 1.02, 95%CI: 1.01-1.03). Current dehydration was correlated with increased all-cause mortality risk in DKD patients (HR = 1.27, 95%CI: 1.01-1.61). Compared to DKD patients with normal hydration, the survival probability of DKD patients with current dehydration was significant lower (p < 0.001).

CONCLUSION

Increased osmolarity level was associated with increased risk of DKD and elevated risk of all-cause mortality in DKD patients.

Fluid and electrolyte balance following consumption of skimmed milk and a plant-based soya beverage at rest in euhydrated males

PURPOSE

Cow's milk is one of the most hydrating beverages, but many individuals choose not to consume dairy in their diet due to intolerance, allergy, or dietary preference. Milk is commonly replaced with plant-based beverages, including soya which has the most comparable protein content, but little is known about their hydration potential. This study compared fluid and electrolyte balance responses between a soya beverage and skimmed cow's milk.

METHODS

Ten healthy males [age 27 (6) y; body mass index 24.6 (2.3) kg/m2] completed two randomised counterbalanced trials, involving consuming 1000 mL water from approximately isocaloric amounts of skimmed cow's milk (MILK) or a sweetened soya beverage (SOYA), in four aliquots over 30 min in a euhydrated fasted state. Volume, specific gravity, and electrolyte (sodium, potassium, chloride) concentrations were determined in total-void urine samples collected pre-/post-beverage ingestion, and hourly for 180 min thereafter. Hunger, thirst, nausea and stomach fullness were rated proximal to urine samples.

RESULTS

Total urine mass (MILK, 986 ± 254 g; SOYA, 950 ± 248 g; P = 0.435) and urine specific gravity (P = 0.156) did not differ between trials. Potassium balance was greater in SOYA 0-180 min post-beverage (P ≤ 0.013), whilst chloride balance was greater in MILK 0-120 min post-beverage (P ≤ 0.036). Sodium balance (P = 0.258), total electrolyte balance (P = 0.258), and subjective measures (P ≥ 0.139) were not different between trials.

CONCLUSION

Replacing cow's milk with a soya beverage did not negatively impact fluid balance in healthy young males, making it a viable option for those who choose not to consume dairy in their diet.

Association of chronic constipation and chronic diarrhea with renal stones: a cross-sectional study of the National Health and Nutrition Examination Survey 2007-2010

Background

Renal stone is a highly prevalent life-long disease with a high recurrence rate. Chronic bowel diseases, including chronic gastrointestinal symptoms (chronic constipation or chronic diarrhea), are common gastrointestinal problems. We aimed to evaluate the associations of chronic constipation and chronic diarrhea with renal stones.

Methods

This large-scale, cross-sectional study was performed within participants (≥20 years old) from the National Health and Nutrition Examination Survey from 2007 to 2010. Logistic regression and sensitivity analyses were conducted to clarify the association between chronic bowel diseases and renal stones.

Results

A total of 8,067 participants aged ≥20 years were included. The prevalence of renal stones is 9.14%. Chronic diarrhea was positively related to the risk of renal stones [odds ratio (OR) =1.681, 95% confidence interval (CI): 1.212 to 2.330, P=0.004] after adjusting for all covariates. In participants with body mass index (BMI) over 30 kg/m2, chronic constipation was correlated with kidney stones in fully adjusted model 2 (OR =2.142, 95% CI: 1.389 to 3.303, P=0.004).

Conclusions

Our findings provide evidence that chronic diarrhea is associated with an increased risk of renal stones. Chronic constipation is positively related to the risk of renal stones in participants with BMI over 30 kg/m2. Health care should focus more on bowel health status for the prevention of related diseases. More prospective cohort studies are needed.

Daily Temperatures and Child Hospital Admissions in Aotearoa New Zealand: Case Time Series Analysis

The influence of global climate change on temperature-related health outcomes among vulnerable populations, particularly young children, is underexplored. Using a case time series design, we analysed 647,000 hospital admissions of children aged under five years old in New Zealand, born between 2000 and 2019. We explored the relationship between daily maximum temperatures and hospital admissions across 2139 statistical areas. We used quasi-Poisson distributed lag non-linear models to account for the delayed effects of temperature over a 0-21-day window. We identified broad ICD code categories associated with heat before combining these for the main analyses. We conducted stratified analyses by ethnicity, sex, and residency, and tested for interactions with long-term temperature, socioeconomic position, and housing tenure. We found J-shaped temperature-response curves with increased risks of hospital admission above 24.1 °C, with greater sensitivity among Māori, Pacific, and Asian compared to European children. Spatial-temporal analysis from 2013-2019 showed rising attributable fractions (AFs) of admissions associated with increasing temperatures, especially in eastern coastal and densely populated areas. Interactive maps were created to allow policymakers to prioritise interventions. Findings emphasize the need for child-specific and location-specific climate change adaptation policies, particularly for socioeconomically disadvantaged groups.

An Evaluation of Healthy Hydration Recommendations for 93 Countries with Sugary Beverage Tax Legislation Globally, 2000-2023

Adequate water intake is essential for human health. Sugary beverage taxes are a best buy policy to reduce obesity and diet-related non-communicable diseases. Food-based dietary guidelines (FBDGs) promote healthy dietary patterns. The study purpose was to evaluate national FBDGs for countries with sugary beverage tax legislation (2000-2023) to promote water and discourage sugary beverage consumption. We developed a coding framework to conduct a content analysis of FBDG documents, and used six indicators to identify messages and images to assign healthy hydration recommendation (HHR) scores from 0-12 to compare FBDGs across countries and six regions. Results showed 93 countries with sugary beverage tax legislation of which 58 countries (62%) had published FBDGs (1998-2023). Of 58 FBDGs reviewed, 48 (83%) had complementary recommendations that encouraged water and discouraged sugary beverages. Of 93 countries, 13 (14%) had the highest HHR scores (11-12); 22, (24%) had high HHR scores (9-10); 20 (21%) had medium HHR scores (4-8); 3 (3%) had low HHR scores (0-3); and 35 (38%) countries had no FBDGs. To reduce health risks for populations, governments must ensure policy coherence to optimize sugary beverage tax impacts by developing FBDGs that encourage water and discourage sugary beverages complementary to national policies.

Psychometric Properties of the Knowledge of Hydration among Foreign Students of Óbuda University, Hungary

It is known that the quantity, makeup, and distribution of bodily fluids have a significant impact on the cognitive health, physiological health, and cell activity of human beings. This narrative could be influenced by the level of knowledge about hydration, dehydration, and the practice of Adequate Water Intake (AWI) of an individual based on the recommended daily Total Water Intake (TWI) by either the World Health Organization (WHO) or the European Food Safety Authority (EFSA). In this study, we have developed and validated a scale to adequately measure knowledge of the recommended daily Total Water Intake (TWI) practices among foreign students at Óbuda University, Hungary. Hence, we implemented an 11-item scale to measure the Knowledge of Hydration (KH-11) and evaluate its psychometric properties among students. This study is an online cross-sectional study assessing water intake knowledge with the use of the KH-11 tool among 323 students with ages ranging from 18 to 35 years, who have enrolled for at least two semesters at the University. The statistical analysis performed was reliability (using Cronbach alpha ≥ 70%) and factor analysis. Knowledge levels were categorized as poor (<50%), intermediate (50-70%), or adequate (71-100%). The intraclass correlation, chi-square, and rotated component matrix were also estimated and reported. Data were analyzed using SPSS version 25. Cronbach's alpha analysis revealed that the KH-11 had an overall good reliability with a value of 0.80, where the survey items had an acceptable level of consistency ranging from 0.75 to 0.81 and demonstrated sufficient independence from each other as Pearson's R within factors was positive and ranged from 0.02 to 0.74. In evaluating the participants' knowledge of hydration, the total possible score for the scale is 72, while the mean score for the KH-11 was 55.2 ± 11.61 SD, and the factor analysis model yielded an acceptable fit (χ2 = 3259.4, p = 0.000). We recorded a high-level positive concordance of 0.770 with an average intraclass correlation of 0.80 at a 95% CI, where p-value = 0.000. Our findings show that the majority (66.3%) of the students have a good knowledge of hydration. However, the skewed distribution of the knowledge scores suggests that some may have lower levels of knowledge, which may warrant further study to improve knowledge in those students.

Predictors of Water Turnover in Older Adults: A Doubly Labeled Water- and Triaxial Accelerometer-Based Study

BACKGROUND

Water is one of the most essential nutrients for life. The water turnover (WT), total body water (TBW), and total energy expenditure (TEE) can be measured using the doubly labeled water (DLW) method. WT and TBW are lower in older adults than in young adults, and the former are susceptible to dehydration, necessitating to identify predictors of the WT in older adults.

OBJECTIVES

The current study aimed to examine the association between WT and physical activity, physical function, and body composition in Japanese adults aged ≥65 y and identify predictors for WT in this population.

METHODS

This study enrolled 133 older adults (women, n = 61; men, n = 72) aged 65-88 y. WT, TBW, TEE, fat-free mass (FFM), and percent body fat (%Fat) were determined using the DLW method. The fitness age score (FAS) was obtained from 5 physical fitness tests. Physical activity and the step count were assessed using a previously validated triaxial accelerometer. Multiple regression analyses were performed with WT as the dependent variable.

RESULTS

WT was positively associated with weight, physical activity level (PAL), moderate-vigorous physical activity, and TEE, and negatively associated with sedentary behavior. We examined potential predictors for WT using age, sex, height, weight, FFM, %Fat, TEE, PAL, and FAS in older Japanese adults.

CONCLUSIONS

Our results confirmed that age, sex, weight, FFM, TEE, and PAL are the potential predictors of WT in older Japanese adults aged ≥65 y.

Utilization of barley and parsley for the management of urolithiasis among the Saudi Arabian population

Objective

To determine the utilization of barley and parsley for managing urolithiasis among the Saudi Arabian population.

Methods

This is a prospective cross-sectional survey-based study. The survey comprised questions about the use of barley, parsley, and other therapies for managing urolithiasis. A WhatsApp® message with the link to the study survey was sent out to family, friends, patients, and other acquaintances residing in the Kingdom of Saudi Arabia (KSA).

Results

A total of 1014 respondents completed the survey, of which 44.8% indicated that they utilized barley, 38.3% stated that they used parsley, and 4.2% indicated that they utilized other non-medical remedies to treat or prevent kidney stones. In contrast, only 29.5% stated that they utilized potassium citrate and/or magnesium citrate, and only 14.4% indicated that they consumed greater amounts of water to treat or prevent kidney stones.

Conclusion

Our study findings indicate that among the Saudi Arabian population, non-conventional therapies such as barley and parsley are more commonly utilized for managing urolithiasis rather than established therapies such as increasing water intake and the use of potassium-citrate/ magnesium-citrate. There is a need to conduct large-scale clinical studies to evaluate the efficacy and safety of barley, parsley, and other non-conventional therapies for treating urolithiasis.

Bioelectrical impedance vector analysis is different according to the comorbidity burden in post-acute myocardial infarction

BACKGROUND

The prevalence of a high comorbidity burden in patients who suffered an acute myocardial infarction (AMI) is increasing with the aging population, and the nutrition status also may be a predictor of clinical outcomes for these patients. This study aimed to investigate the relationship between the comorbidity burden and the characteristics of the bioelectrical impedance vector analysis (BIVA) in patients post-AMI.

METHODS

This prospective observational cohort study was conducted with adult patients who were hospitalized with AMI. Pre-existing comorbidities were assessed by the Charlson comorbidity index (CCI) adjusted by age, and anthropometric and BIVA characteristics were evaluated after the hemodynamic stabilization. All patients were followed-up until hospital discharge, and their length of stay was observed.

RESULTS

A total of 184 patients (75% were males; mean age, 60.2 ± 12.3 years) were included. The most common comorbidities were dyslipidemia (73.9%), hypertension (62%), and type 2 diabetes (34.2%). A higher CCI (≥3) was associated with sex (P = 0.008) and age (P < 0.001). Regarding BIVA, statistically significant differences were detected between sex (P < 0.001), age (P < 0.001), and CCI (P = 0.003), with longer vectors in female, older adults, and those with CCI ≥ 3.

CONCLUSION

Finding a relationship between BIVA and CCI suggests the first identified coherent differences, potentially correlated with diseases, representing a first contribution to support this type of assessment. Therefore, with BIVA, healthcare professionals may monitor abnormalities and adopt preventive nutrition care measures on patients post-AMI to improve their clinical status.

Effect of a cajuína hydroelectrolytic drink on the physical performance and hydration status of recreational runners

Cajuína is a processed drink derived from cashew and is widely consumed in the northeast region of Brazil. This study evaluated the effect of a cajuína-based hydroelectrolytic drink on the aerobic performance and hydration status of recreational runners. Seventeen males (31.9 ± 1.6 years, 51.0 ± 1.4 ml/kg/min) performed three time-to-exhaustion running sessions on a treadmill at 70% VO2max, ingesting cajuína hydroelectrolytic drink (CJ), high carbohydrate commercial hydroelectrolytic drink (CH) and mineral water (W) every 15 min during the running test. The participants ran 80.3 ± 8.4 min in CJ, 70.3 ± 6.8 min in CH and 71.8 ± 6.9 min in W, with no statistical difference between procedures. Nevertheless, an effect size of η2 = 0.10 (moderate) was observed. No statistical difference was observed in the concentrations of sodium, potassium, and osmolality in both serum and urine between the three conditions. However, the effect size was moderate (urine sodium) and high (serum sodium, potassium, and osmolality). Urine specific gravity, sweating rate and heart rate were not significantly different between drinks. The cajuína-based hydroelectrolytic drink promotes similar effects compared to commercial hydroelectrolytic drink and water, considering specific urine gravity, heart rate, sweating, and time to exhaustion in recreational runners.

Personality Determinants Related to the Use of Selective and Effective Dietary Supplements by Elite Polish Team Sport Athletes

INTRODUCTION

The purpose of this research was to analyse relationships between personality traits and the use of selected dietary supplements among Polish athletes training in team sports. This subject matter has not been explored in prior research.

MATERIAL AND METHODS

This research was carried out among a group of 213 athletes (men) in the 18-36 age range, with the implementation of a proprietary validated questionnaire for the use of dietary supplements and the NEO-PI-R inventory (Neuroticism-Extraversion-Openness Personality Inventory-Revised). Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney tests, assuming the following level of significance: α = 0.05.

RESULTS

It was shown that athletes who periodically and regularly consumed isotonic drinks, as well as energy bars and gels, were characterised by a lower level of neuroticism than those who did not consume them. Athletes who periodically took multivitamin preparations were characterised by a lower level of extraversion and openness, and those periodically using multimineral preparations were characterised by a higher level of agreeableness than those who did not use these agents. Athletes not taking creatine were characterised by the lowest level of conscientiousness among the study participants. The use of protein nutrients, probiotics and caffeine was not associated with any personality traits in the athletes.

CONCLUSIONS

Further relationships of the Big Five personality traits were demonstrated with the use of effective dietary supplements by athletes; the most unambiguous correlations were described for neuroticism and conscientiousness in such a way that the use of isotonic drinks, as well as energy bars and gels, was connected with a low level of neuroticism, while the use of creatine was connected with high conscientiousness.

Association between plain water intake and risk of hypertension: longitudinal analyses from the China Health and Nutrition Survey

Objective

This study aimed to investigate the prospective association between plain water intake and the risk of hypertension based on a longitudinal cohort study in China.

Methods

Logistic regression analyses were performed to investigate the association between plain water intake and hypertension. Restricted cubic spline model was use to evaluate non-linear relationship between plain water intake and hypertension. Subgroup analyses and interaction tests were conducted based on age, gender, residence site, educational level and tea consumption.

Results

A total of 3,823 participants (46.5% male) with a mean age of 46.8 years from the China Health and Nutrition Survey (CHNS) were assessed and divided into 4 groups based on plain water intake. There was a decreasing trend of hypertension risk as plain water intake increased. Logistic regression analyses indicated that participants consuming plain water ≥6 cups/day (1 cup ≈ 240 mL) had significantly lower risk of hypertension compared to those consuming ≤1 cup/day, even after adjustments for covariates. Restricted cubic spline curve revealed that participants consuming about 6-8 cups/day were at lower risk for developing hypertension. In subgroup analyses, the results were generally consistent with the main findings in participants who aged less than 60 years, who were male, who attained higher education and who were low tea consumers.

Conclusion

Our findings suggested that there might be a favorable effect of plain water intake on preventing hypertension in a large cohort of Chinese adults from the general population. Drinking adequate amounts of plain water (about 6-8 cups/day) may reduce the risk of hypertension, particularly in the selected population. Further interventional studies are required to investigate the potential effect of increasing plain water intake on blood pressure regulation.

Association of plain water intake with self-reported depression and suicidality among Korean adolescents

OBJECTIVES

Adolescent depression and suicidality are serious health problems worldwide. Lower plain water intake has been proposed as a risk factor for depression in adults. This study investigated the association of daily plain water intake with self-reported depression and suicidality among Korean adolescents.

METHODS

We used nationwide data from 112,250 students aged 12-18 years who participated in the Korean Youth Risk Behavior Web-based Surveys in 2019 and 2020. Daily plain water intake was categorized as <1 glass, 1-2 glasses, and ≥3 glasses. The adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for self-reported depression and suicidality were calculated using multiple regression analyses.

RESULTS

The weighted prevalence rates of self-reported depression, suicidal ideation, suicide planning, and suicide attempts were 26.7%, 12.0%, 3.8%, and 2.5%, respectively. Of the participants, 3.9%, 18.5%, and 77.7% were categorized into the <1 glass/day, 1-2 glass/day, and ≥3 glass/day groups, respectively. Compared to the reference group (≥3 glass/day), the lowest level of water intake (<1 glass/day) was associated with higher odds of self-reported depression (aOR, 1.30; 95% CI, 1.20 to 1.39), suicidal ideation (aOR, 1.39; 95% CI, 1.27 to 1.55), suicide planning (aOR, 1.46; 95% CI, 1.25 to 1.69), and suicide attempts (aOR, 1.38; 95% CI, 1.15 to 1.67). Moderately lower water intake (1-2 glass/day) showed slightly increased odds of self-reported depression (aOR, 1.05; 95% CI, 1.01 to 1.10) and suicidal ideation (aOR, 1.08; 95% CI, 1.03 to 1.14).

CONCLUSIONS

Lower plain water intake was significantly associated with a higher risk of self-reported depression and suicidality among Korean adolescents. Since this cross-sectional study is unable to establish a causal relationship, it underscores the need for additional longitudinal research.

Fluid and water balance: a scoping review for the Nordic Nutrition Recommendations 2023

Water, being an essential nutrient, is crucial for all life. Adequate maintenance of body water compartments is required for optimal fluid balance, which is a prerequisite for cellular homeostasis and blood pressure regulation. Water balance is the result of dietary intake of both fluids and foods as well as metabolically produced water, excretion from the kidneys and losses from other sources (e.g. sweat and feces). The water content in food items varies considerably and ranges from about 5% in nuts to 90% in many fruits and vegetables. Intake of drinking water and beverages also provides varying amounts of water. In everyday life assessment of water balance (i.e. hydration status) is challenging as clinical observations are inaccurate. There is no data regarding drinking water intake in the Nordic or Baltic countries.

Underestimated health risks: Dietary restriction magnify the intestinal barrier dysfunction and liver injury in mice induced by polystyrene microplastics

Microplastics (MPs) have gained significant attention due to their widespread presence in the environment. While studies have been conducted to investigate the risks associated with MPs, the potential effects of MPs on populations with varying dietary habits, such as dietary restriction (DR), remain largely undefined. The sensitivity of the body to invasive contaminants may increase due to insufficient food intake. Here, we aimed to investigate whether dietary restriction could affect the toxicity of MPs in mice. Following a 5-week exposure to 200 μg/L polystyrene microplastics (PSMPs), DR-PSMPs treatment group exhibited significant intestinal barrier dysfunction compared to ND-PSMPs treatment group, as determined by histopathological and biochemical analysis. Dietary restriction worsened liver oxidative stress and bile acid disorder in mice exposed to PSMPs. 16S rRNA sequencing analysis revealed that DR-PSMPs treatment caused alterations in gut microbiota composition, including the downregulation of probiotics abundance and upregulation of pathogenic bacteria abundance. The negative effects caused by PSMPs in mice with dietary restriction could attribute to increased MPs bioaccumulation, declined water intake, reduced probiotics abundance, and elevated pathogenic bacteria abundance, as well as the susceptibility of the dietary restriction individual. Our findings hint that the biological effects of contaminants could be affected by dietary habits.

Healthy Drinking Water as a Necessity in Developing Countries Like India: A Narrative review

Water is an indispensable part of human life. This article is an extensive review that focuses on the importance of water to sustain human life, the necessity of healthy, safe drinking water, and the health hazards of drinking untreated and contaminated water. We drink treated water thinking it to be safe without the knowledge that it, too, has harmful effects. Detrimental health effects due to water chlorination are mentioned in this article. The usage of nanoparticles for the treatment of water is an alternative to chlorination, but they are little in use as they are expensive. Transmission of waterborne diseases through drinking water is widespread in a developing country like India. A list of the pathogens contaminating drinking water is present in the review. Pathogens pollute water, and heavy metals and chemicals from industries, pesticides, pharmaceutical compounds, and radioactive waste also taint it. The harmful effects of metal and chemical toxicities on human health are discussed in this review. The government of India has launched several programmes to ensure clean, safe drinking water for all its residents. The study reflects on the treatment given to individuals suffering from waterborne diseases in India. Significant changes in health status in India have been seen recently after the execution of various government programmes to provide safe, healthy drinking water to all its residents.

Decreasing consumption of sugar-sweetened beverages and Raising tap water consumption through Interventions based on Nutrition and sustainability for Kids: study protocol of the "DRINK" cluster randomised controlled trial

BACKGROUND

Effectiveness of actions to reduce sugar-sweetened beverage (SB) consumption in children still needs to be improved. Furthermore, the growing concern about sustainable food systems encourages to develop sustainability-based interventions. The objective of this cluster randomised controlled trial is to evaluate the long-term effectiveness of nutrition- and environmental sustainability-based interventions on the reduction in SB intake and on the increase in tap water consumption in 3rd to 6th grade primary school children (8 to 11 years of age).

METHODS

Forty-eight French-speaking Belgian primary schools (equivalent to around 3500 pupils involved in the evaluation) are randomised using a factorial plan: (i) control, (ii) nutrition-based intervention, (iii) sustainability-based intervention, and (iv) both. The interventions (encouragement of water breaks; provision of posters, leaflets, reusable cups, and glass bottles; website; meetings at school) were undertaken from February 2022 to June 2023. Evaluation includes questionnaires for the children and their parents on various determinants of dietary behaviour, a 4-day diary to collect information on the child's beverage consumption, and audits at schools. The first evaluation was conducted in Spring 2021 before any intervention, with the two post-intervention evaluations being held in 2022 and 2023. The main quantitative judgement criterion will be the change over time in the mean SB consumption (in ml/day) in the intervention groups compared with the control group. Given the context of the research (school), the safety of the intervention, and the content of data collection, a consent was acknowledged as unnecessary by the Ethical Committee of the Faculty of Psychology (ULB; n°073/2021), but children and parents are explicitly informed of their right to refuse to fill in the questionnaires.

DISCUSSION

Multicomponent interventions based on nutrition and on environmental sustainability, alone or mixed, will provide an original and topical insight into health promotion at school around dietary behaviours. The dissemination plan will enable to widely inform stakeholders, school staff, and families, in addition to the scientific community through the usual medium (articles, conferences), about the research findings in 2024-2025.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN99843102. Retrospectively registered on 25 May 2021.

Fluid intake at work in foresters working in different thermal conditions

The primary aim of this study was to assess the impact of fluid intake on hydration status indices in men at work. The secondary aim was to determine the type of fluids drunk at work in different thermal conditions. Fifty-nine male foresters were examined before and after one working day during summer, autumn, and winter. Before and after work, urine and blood samples were obtained from foresters. Immediately after a shift, participants completed a questionnaire regarding fluid intake during one working day. The amount of fluid consumed affects the hydration urine indices. Urine specific gravity and urine osmolality significantly decreased with increasing fluid intake (r = - 0.385 and r = - 0.405, respectively). Moreover, an impact of season on the type of fluids consumed by workers was observed. Tea was significantly more often chosen by workers to drink in winter (68%) than in summer (32%) (p = 0.026). The consumption of any non-alcoholic fluids contributes to the daily total water intake, but it is necessary to create individualized fluid replacement plans. Workers should know how much and what types of drinks to consume at work.

Screen-Printed Wearable Sweat Sensor for Cost-Effective Assessment of Human Hydration Status through Potassium and Sodium Ion Detection

Human sweat is intricately linked to human health, and unraveling its secrets necessitates a substantial volume of experimental data. However, conventional sensors fabricated via complex processes such as photolithography offer high detection precision at the expense of prohibitive costs. In this study, we presented a cost-effective and high-performance wearable flexible sweat sensor for real-time monitoring of K+ and Na+ concentrations in human sweat, fabricated using screen printing technology. Initially, we evaluated the electrical and electrochemical stability of the screen-printed substrate electrodes, which demonstrated good consistency with a variation within 10% of the relative standard deviation (RSD), meeting the requirements for reliable detection of K+ and Na+ in human sweat. Subsequently, we employed an "ion-electron" transduction layer and an ion-selective membrane to construct the sensors for detecting K+ and Na+. Comprehensive tests were conducted to assess the sensors' sensitivity, linearity, repeatability, resistance to interference, and mechanical deformation capabilities. Furthermore, we evaluated their long-term stability during continuous monitoring and storage. The test results confirmed that the sensor's performance indicators, as mentioned above, met the requirements for analyzing human sweat. In a 10-day continuous and regular monitoring experiment involving volunteers wearing the sensors, a wealth of data revealed a close relationship between K+ and Na+ concentrations in human sweat and hydration status. Notably, we observed that consistent and regular physical exercise effectively enhanced the body's resistance to dehydration. These findings provided a solid foundation for conducting extensive experiments and further exploring the intricate relationship between human sweat and overall health. Our research paved a practical and feasible path for future studies in this domain.

A Content Analysis of Persuasive Appeals Used in Media Campaigns to Encourage and Discourage Sugary Beverages and Water in the United States

The frequent consumption of sugary beverages is associated with many health risks. This study examined how persuasive appeals and graphics were used in different media campaigns to encourage and discourage sugary beverages and water in the United States (U.S.) The investigators developed a codebook, protocol and systematic process to conduct a qualitative content analysis for 280 media campaigns organized into a typology with six categories. SPSS version 28.0 was used to analyze rational and emotional appeals (i.e., positive, negative, coactive) for campaign slogans, taglines and graphic images (i.e., symbols, colors, audiences) for 60 unique campaigns across the typology. Results showed that positive emotional appeals were used more to promote sugary beverages in corporate advertising and marketing (64.7%) and social responsibility campaigns (68.8%), and less to encourage water in social marketing campaigns (30%). In contrast, public awareness campaigns used negative emotional appeals (48.1%), and advocacy campaigns combined rational (30%) and emotional positive (50%) and negative appeals (30%). Public policy campaigns used rational (82.6%) and positive emotional appeals (73.9%) to motivate support or opposition for sugary beverage tax legislation. Chi-square analyses assessed the relationships between the U.S. media campaign typology categories and graphic elements that revealed three variables with significant associations between the campaign typology and race/ethnicity (χ²(103) = 32.445, p = 0.039), content (χ²(103) = 70.760, p < 0.001) and product image (χ²(103) = 11.930, p = 0.036). Future research should examine how positive persuasive appeals in text and graphics can promote water to reduce sugary beverage health risks.

Hydration Status in Older Adults: Current Knowledge and Future Challenges

Adequate hydration is essential for the maintenance of health and physiological functions in humans. However, many older adults do not maintain adequate hydration, which is under-recognized and poorly managed. Older adults are more vulnerable to dehydration, especially those living with multiple chronic diseases. Dehydration is associated with adverse health outcomes in older adults, and acts as an independent factor of the hospital length of stay, readmission, intensive care, in-hospital mortality, and poor prognosis. Dehydration is a prevalent health problem in older adults, accounting for substantial economic and social burden. This review attempts to provide current knowledge of hydration including patterns of body water turnover, the complex mechanisms behind water homeostasis, the effects of dehydration on the health of the body, and practical guidance for low-intake dehydration in older adults.

Dietary Nutrient Deficiencies and Risk of Depression (Review Article 2018-2023)

Depression is classified as one of the most common mental disorders. Its prevalence has recently increased, becoming a growing public health threat. This review focuses on clarifying the role and importance of individual nutrients in the diet and the impact of nutrient deficiencies on the risk of depression. Deficiencies in nutrients such as protein, B vitamins, vitamin D, magnesium, zinc, selenium, iron, calcium, and omega-3 fatty acids have a significant impact on brain and nervous system function, which can affect the appearance of depressive symptoms. However, it is important to remember that diet in itself is not the only factor influencing the risk of or helping to treat depression. There are many other aspects, such as physical activity, sleep, stress management, and social support, that also play an important role in maintaining mental health. The data review observed that most of the available analyses are based on cross-sectional studies. Further studies, including prospective cohort, case-control studies, are recommended to draw more reliable conclusions.

Can a simple plan change a complex behavior? Implementation intentions in the context of water drinking

Underhydration has significant adverse physical and mental health effects, yet many people drink too little water. Implementation intentions have been found to effectively promote many health behaviors, but little is known about the processes underlying their effects in naturalistic settings, and whether they could improve water drinking. This mixed-methods study assessed the impact and potential underlying processes of using implementation intentions to increase self-reported water intake over a five-day follow-up. Ninety-five participants (Mage = 39, SD = 12) received an educational quiz to increase their water drinking motivation before being randomly assigned to the control or intervention group. Participants also completed a qualitative survey that assessed the processes underlying their attempts to increase water intake. Quantitative results suggested that most participants increased their average daily water intake regardless of group. Qualitative results indicated that implementation intention participants struggled with remembering and the perceived effort of preparation and drinking behaviors, which reduced the effect of planning on behavior. This study provides essential theoretical and methodological considerations for researchers studying implementation intentions, as the effects and mechanisms of implementation intentions in real-life situations may be more complex than previously assumed. For example, the results suggest that implementation intentions did not automatize remembering and performing the behavior in ways the current literature theorizes. Other kinds of interventions may be needed to improve the complex daily-life behaviour of water drinking.

Atopic Dermatitis and Water: Is There an Optimum Water Intake Level for Improving Atopic Skin?

Water is a vital nutrient with innumerable functions for every living cell. The functions of human skin include protection against dehydration of the body. Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease that presents with dry skin, erythematous and eczematous lesions, and lichenification. This paper discusses the question of whether extra water intake in children with AD affects skin hydration and the skin barrier function. Among the methods used to treat dry skin, topical leave-on products are the first-line treatment, intended to improve hydration and the skin barrier function. The effectiveness of adequate water intake as a measure to treat dry skin is still under debate. Normal skin hydration increases with dietary water intake, particularly in those with prior lower water consumption. Skin dryness in AD is instrumental to the itch and inflammation cycle, contributing to barrier impairment and aggravating disease severity and flares. Certain emollients provide significant hydration to AD skin, with relief of dryness and reduction in barrier impairment, disease severity, and flares. Further investigations are needed to evaluate the optimum water intake levels in children with AD, as important questions remain unanswered, namely, does oral hydration provide relief of skin dryness and reduce barrier impairment, disease severity, and flares; is there any additional benefit from using mineral or thermal spring water; or is there a need to specifically study the fluid/water intake in children with AD and food allergy (FA) restrictions?

Characterization of Metallic Off-Flavors in Drinking Water: Health, Consumption, and Sensory Perception

Characterization of taste- and flavor-producing metals, namely iron and copper, in drinking water is a multifaceted subject. Both metals are essential nutrients, can be toxic, and are known to produce unpleasant tastes and flavor sensations in drinking water. Ingestion of trace metal contaminants through drinking water is a probable source of human exposure. Biochemical mechanisms of metallic flavor perception have been previously described; however, less is known about how variations in salivary constituents might impact individuals' sensitivities to metallic flavors and beverage consumption behaviors. This research presents findings from in vitro experiments, using artificial human saliva, to better understand the role of salivary lipids and proteins on metallic flavor production as measured by biomarkers of metal-induced oxidative stress. The results indicate that metal-induced lipid oxidation, as measured by thiobarbituric acid reactive substances (TBARS), is dominated by salivary proteins, is slightly inhibited in the presence of salivary nitrite, and is detectable by the TBARS method at and above respective concentrations of 9 µM (0.5 mg/L) and 90 µM (5 mg/L), which are both above the aesthetic standards for iron (0.3 mg/L) and copper (1.0 mg/L) in drinking water. Preliminary study with human subjects indicated that reduction in metallic flavor sensitivity, as measured by the best estimate flavor threshold for ferrous iron among 33 healthy adults aged 19-84 years old (22 females), corresponded with reduced drinking water consumption and increased caloric beverage intake among older subjects (>60 years), as determined by a validated self-reported beverage intake questionnaire. These findings provide insights for further research to examine how salivary constituents can impact humans' sensory abilities in detecting metallic off-flavors in water, and how reduced metallic flavor sensitivity may influence beverage choices and drinking water consumption.

Proteomic analysis reveals that aging rabbit vocal folds are more vulnerable to changes caused by systemic dehydration

BACKGROUND

Older adults are more prone to develop systemic dehydration. Systemic dehydration has implications for vocal fold biology by affecting gene and protein expression. The objective of this study was to quantify vocal fold protein changes between two age groups and hydration status, and to investigate the interaction of age and hydration status on protein expression, which has not been investigated in the context of vocal folds before. Comparative proteomics was used to analyze the vocal fold proteome of 6.5-month-old and > 3-year-old rabbits subjected to water ad libitum or water volume restriction protocol.

RESULTS

Young and older adult rabbits (n = 22) were either euhydrated (water ad libitum) or dehydrated by water volume restriction. Dehydration was confirmed by body weight loss of - 5.4% and - 4.6% in young and older groups, respectively, and a 1.7-fold increase of kidney renin gene expression in the young rabbits. LC-MS/MS identified 2286 proteins in the rabbit vocal folds of young and older adult rabbits combined. Of these, 177, 169, and 81 proteins were significantly (p ≤ 0.05) affected by age, hydration status, or the interaction of both factors, respectively. Analysis of the interaction effect revealed 32 proteins with opposite change patterns after dehydration between older and young rabbit vocal folds, while 31 proteins were differentially regulated only in the older adult rabbits and ten only in the young rabbits in response to systemic dehydration. The magnitude of changes for either up or downregulated proteins was higher in the older rabbits. These proteins are predominantly related to structural components of the extracellular matrix and muscle layer, suggesting a disturbance in the viscoelastic properties of aging vocal fold tissue, especially when subjected to systemic dehydration.

CONCLUSIONS

Water restriction is a laboratory protocol to assess systemic dehydration-related changes in the vocal fold tissue that is translatable to human subjects. Our findings showed a higher number of proteins differentially regulated with a greater magnitude of change in the vocal folds of older adult rabbits in the presence of systemic dehydration compared to younger rabbits. The association of these proteins with vocal fold structure and biomechanical properties suggests that older human subjects may be more vulnerable to the effects of systemic dehydration on vocal function. The clinical implications of these protein changes warrant more investigation, but age should be taken into consideration when evaluating vocal treatment recommendations that interfere with body fluid balance.

Children's water intake and hydration: a public health issue

Optimal hydration is required for all physiologic functions and cognition. Children, especially younger ones, are particularly susceptible to dehydration, given their physiological specificities, in particular, their renal immaturity and relatively large skin surface in early life, but also their dependence on adults and their greater propensity to develop digestive diseases leading to fluid losses. Mild dehydration consequences are dominated by their impact on cognitive functions, whereas more severe dehydration may endanger the health outcome. Studies on this subject in children are scarce; in particular, the long-term consequence on renal function remains questionable. This review considers how children's water intake including fluid intake and water content of food, are worrying. The findings show that, worldwide, most children do not meet adequate water intake recommendations. The main problems likely to explain insufficient water intake are access to safe water, availability of drinking water at school, and healthy-hydration education, which are all points that need to be improved within health policy.

An accurate wearable hydration sensor: Real-world evaluation of practical use

A wearable body hydration sensor employing photoplethysmographic and galvanic biosensors was field evaluated using 240 human participants with equal numbers of men and women volunteers. Monitoring of water mass loss due to perspiration was performed by medical balance measurements following one of two different treadmill physical exercise regimens over 90 minutes in 15-minute intervals with intervening 10-minute rest periods. Participants wore two different models of the dehydration body monitor device mated to commercially-available smartwatches (Samsung Gear S2 and Samsung Gear Fit2). Device output was recorded by Bluetooth wireless link to a standard smartphone in 20-second blocks. Comparison of the devices with the standard measurement method (change in body mass measured by medical balance) indicated very close agreement between changes in body water mass and device output (percent normalized mean root square error averaged approximately 2% for all participants). Bland-Altman analyses of method agreement indicated that <5% of participant values fell outside of the 95% confidence interval limits of agreement and all measured value differences were normally distributed around the line of equality. The results of this first-ever field trial of a practical, wearable hydration monitor suggests that this device will be a reliable tool to aid in geriatric hydration monitoring and physical training scenarios.

Total water intake and its contributors in infants and young children

Hydration is a particular concern for infants and young children due to their greater risk of dehydration. However, studies on their water intakes are scarce. The current survey aimed to analyse total water intake (TWI) in non-breastfed children aged 0·5-35 months compared with the adequate intake (AI) for the same age group set by the European Food Safety Authority and to examine the different contributors to TWI as well as beverage consumption patterns. Nationally representative data from the Nutri-Bébé cross-sectional survey were used to assess food, beverage and plain water consumption by age group over three non-consecutive days. With age, median TWI in 1035 children increased from 732 to 1010 ml/d, without differences between sexes, but with a great inter-individual variation, and the percentage of children who did not meet the AI increased from 10 to 88 %. Median weight-related TWI decreased from 136·6 to 69·0 ml/kg per d. Among infants, 90 % had a ratio of water:energy below the AI, similarly for about 75 % of toddlers. Milk and milk products were the main contributors to TWI, while the part of plain water increased gradually to be 25 % in the older toddlers, half of which was tap water. The beverage consumption pattern varied in types and timing, with little consumption of juices and sweetened beverages. Vegetables and fruits accounted for 20 % of TWI after the age of 6 months. These initial results, showing strong discrepancies between actual and recommended water intakes in young children, should help identify ways to increase children's water consumption.

Interaction of Hydration Status and Physical Activity Level on Early Renal Damage in Children: A Longitudinal Study

Background

Optimal water intake positively affects various aspects of human physiology, especially renal function. Physical activity (PA) may have an impact on hydration status and renal health, but the interaction of hydration status and PA level on renal function is not well-studied in children.

Methods

We conducted four waves of urine assays in our child cohort (PROC) study from October 2018 to November 2019 in Beijing, China. We measured urinary specific gravity, β2-microglobulin (β2-MG), and microalbumin (MA) excretion to assess hydration status and renal damage in the context of PA level and other covariates among 1,914 primary school children. We determined the associations of renal damage with the interaction of hydration status and PA level using generalized linear mixed-effects models.

Results

The prevalence of dehydration was 35.0%, 62.1%, 63.9%, and 63.3%, and the prevalence of insufficient PA was 86.2%, 44.9%, 90.4%, and 90.2% from wave 1 to wave 4 among 1,914 primary school children. From wave 1 to wave 4, the prevalence of renal tubular damage had a significant increasing trend of 8.8%, 15.9%, 25.7%, and 29.0% (Z = 16.9, P &lt; 0.001), while the prevalence of glomerular damage revealed a declining trend of 5.6%, 5.5%, 4.4%, and 4.1% (Z = −2.4, P = 0.016). There were stable longitudinal associations of renal tubular and glomerular damage with hydration status (euhydration: OR = 0.50 and 0.33, respectively) but not with PA level. In multivariate analysis, significant interactions of hydration status and PA level were noted with renal tubular damage (β = 0.43, P = 0.014) and glomerular damage (β = 0.60, P = 0.047). Children with euhydration and insufficient PA were less likely to have renal tubular damage (OR = 0.46, 95% CI: 0.39, 0.53) or glomerular damage (OR = 0.28, 95% CI: 0.20, 0.39); children with euhydration and sufficient PA were also less likely to have renal tubular damage (OR = 0.57, 95% CI: 0.44, 0.75) or glomerular damage (OR = 0.47, 95% CI: 0.30, 0.74), adjusting for age, sex, BMI z-score, standardized SBP, sleep duration, computer/cell phone screen time, and fruit and vegetable intake.

Conclusion

Children with euhydration and either sufficient or insufficient PA were less likely to have early renal damage. Adequate daily water intake for children is important, especially after PA.

Associations between hydration status, body composition, sociodemographic and lifestyle factors in the general population: a cross-sectional study

Background

Whole-body hydration status is associated with several health outcomes, such as dehydration, edema and hypertension, but little is known about the nonclinical determinants. Therefore, we studied the associations of sex, age, body composition, nutrition, and physical activity on several body hydration measures.

Methods

We assessed sociodemographic variables, dietary habits, and physical activity by questionnaire and body composition by bioelectric impedance analysis (BIA). We compared determinants between the sexes and calculated associations between determinants and BIVA hydration measures by multivariable linear regressions.

Results

A total of 242 adults from the general population (age 18–94, 47% women) were included. Women were younger, smaller, lighter, and had a smaller BMI (kg/m²) than men (p < 0.05). Women had less muscle mass, less visceral fat mass and less extracellular and intracellular water than men (p < 0.001). Women showed less intracellular water per extracellular water than men, while men showed higher phase angle values than women (both p < 0.001). Men had a stronger association of hydration measures with physical activity than women. Both sexes showed a decrease in hydration measures with age.

Conclusions

Sex, age, body composition, and physical activity influence body hydration. There seem to be differences in body water regulation between the sexes. Especially interesting are factors susceptible to preventive measures such as physical activity.

Hydration Status in Men Working in Different Thermal Environments: A Pilot Study

The aim of this study was to determine the effects of different seasons of the year and the time of day (before work vs. after work) on hydration status in men. The study involved sixty foresters who spent most of the work outdoors. During three seasons of the year (summer, autumn, and winter), indices of hydration status (body mass (BM) and percentage change of BM, total body water (TBW) and percentage change of TBW, serum osmolality (Sosm) and percentage change of Sosm, urine osmolality, urine-specific gravity (USG), urine color, and thirst) were determined before work on the first day (time point 1 used as baseline), immediately after work on the first day (time point 2), and before work on the following day (time point 3). USG decreased at time point 2 compared to time point 1 (p < 0.001) and time point 3 (p = 0.03). At time point 2 (p = 0.002) in winter and time point 3 in autumn (p = 0.049), serum osmolality was higher than in summer. In conclusion, the differences in hydration status depended on the time of day and season. A large percentage of foresters come to work inadequately hydrated, especially in colder seasons compared to summer.

Low-carbohydrate versus balanced-carbohydrate diets for reducing weight and cardiovascular risk

BACKGROUND

Debates on effective and safe diets for managing obesity in adults are ongoing. Low-carbohydrate weight-reducing diets (also known as 'low-carb diets') continue to be widely promoted, marketed and commercialised as being more effective for weight loss, and healthier, than 'balanced'-carbohydrate weight-reducing diets.

OBJECTIVES

To compare the effects of low-carbohydrate weight-reducing diets to weight-reducing diets with balanced ranges of carbohydrates, in relation to changes in weight and cardiovascular risk, in overweight and obese adults without and with type 2 diabetes mellitus (T2DM).

SEARCH METHODS

We searched MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection (Clarivate Analytics), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) up to 25 June 2021, and screened reference lists of included trials and relevant systematic reviews. Language or publication restrictions were not applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults (18 years+) who were overweight or living with obesity, without or with T2DM, and without or with cardiovascular conditions or risk factors. Trials had to compare low-carbohydrate weight-reducing diets to balanced-carbohydrate (45% to 65% of total energy (TE)) weight-reducing diets, have a weight-reducing phase of 2 weeks or longer and be explicitly implemented for the primary purpose of reducing weight, with or without advice to restrict energy intake.  DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts and full-text articles to determine eligibility; and independently extracted data, assessed risk of bias using RoB 2 and assessed the certainty of the evidence using GRADE. We stratified analyses by participants without and with T2DM, and by diets with weight-reducing phases only and those with weight-reducing phases followed by weight-maintenance phases. Primary outcomes were change in body weight (kg) and the number of participants per group with weight loss of at least 5%, assessed at short- (three months to < 12 months) and long-term (≥ 12 months) follow-up.

MAIN RESULTS

We included 61 parallel-arm RCTs that randomised 6925 participants to either low-carbohydrate or balanced-carbohydrate weight-reducing diets. All trials were conducted in high-income countries except for one in China. Most participants (n = 5118 randomised) did not have T2DM. Mean baseline weight across trials was 95 kg (range 66 to 132 kg). Participants with T2DM were older (mean 57 years, range 50 to 65) than those without T2DM (mean 45 years, range 22 to 62). Most trials included men and women (42/61; 3/19 men only; 16/19 women only), and people without baseline cardiovascular conditions, risk factors or events (36/61). Mean baseline diastolic blood pressure (DBP) and low-density lipoprotein (LDL) cholesterol across trials were within normal ranges. The longest weight-reducing phase of diets was two years in participants without and with T2DM. Evidence from studies with weight-reducing phases followed by weight-maintenance phases was limited. Most trials investigated low-carbohydrate diets (> 50 g to 150 g per day or < 45% of TE; n = 42), followed by very low (≤ 50 g per day or < 10% of TE; n = 14), and then incremental increases from very low to low (n = 5). The most common diets compared were low-carbohydrate, balanced-fat (20 to 35% of TE) and high-protein (> 20% of TE) treatment diets versus control diets balanced for the three macronutrients (24/61). In most trials (45/61) the energy prescription or approach used to restrict energy intake was similar in both groups. We assessed the overall risk of bias of outcomes across trials as predominantly high, mostly from bias due to missing outcome data. Using GRADE, we assessed the certainty of evidence as moderate to very low across outcomes.  Participants without and with T2DM lost weight when following weight-reducing phases of both diets at the short (range: 12.2 to 0.33 kg) and long term (range: 13.1 to 1.7 kg).  In overweight and obese participants without T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to 8.5 months (mean difference (MD) -1.07 kg, (95% confidence interval (CI) -1.55 to -0.59, I2 = 51%, 3286 participants, 37 RCTs, moderate-certainty evidence) and over one to two years (MD -0.93 kg, 95% CI -1.81 to -0.04, I2 = 40%, 1805 participants, 14 RCTs, moderate-certainty evidence); as well as change in DBP and LDL cholesterol over one to two years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one year (risk ratio (RR) 1.11, 95% CI 0.94 to 1.31, I2 = 17%, 137 participants, 2 RCTs, very low-certainty evidence).  In overweight and obese participants with T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to six months (MD -1.26 kg, 95% CI -2.44 to -0.09, I2 = 47%, 1114 participants, 14 RCTs, moderate-certainty evidence) and over one to two years (MD -0.33 kg, 95% CI -2.13 to 1.46, I2 = 10%, 813 participants, 7 RCTs, moderate-certainty evidence); as well in change in DBP, HbA1c and LDL cholesterol over 1 to 2 years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one to two years (RR 0.90, 95% CI 0.68 to 1.20, I2 = 0%, 106 participants, 2 RCTs, very low-certainty evidence).  Evidence on participant-reported adverse effects was limited, and we could not draw any conclusions about these.  AUTHORS' CONCLUSIONS: There is probably little to no difference in weight reduction and changes in cardiovascular risk factors up to two years' follow-up, when overweight and obese participants without and with T2DM are randomised to either low-carbohydrate or balanced-carbohydrate weight-reducing diets.

A study on accuracy and precision of fluid volume measurements by nurses, patients and healthy persons in a clinical setting

AIM

To evaluate the accuracy and precision for assessing fluid intake by examining the ability of nurses, patients and healthy people to visually estimate fluid volumes, thereby reflecting the fluid monitoring process in clinical practice.

DESIGN

A cross-sectional study.

METHODS

This study used the convenience sampling method and involved twenty-five participants from three groups; nurses, patients and healthy people. The participants carried out a set of different visual volume assessments of two types of fluids using two fluid containers. The exact volumes were measured, and the results were compared with the target volumes.

RESULTS

High variations were observed in the fluid volume assessments for patients, nurses and healthy persons and also were observed to be an effect of environmental factors (fluid container or fluid type) on volume perceptions. This highlights the importance of finding new and innovative ways of measuring fluids for oral intake in a hospital setting, to ensure accurate and reliable data on fluid balance and thereby increase patient safety.

Anxiety, fear and stress feelings of road users during daily walking in COVID-19 pandemic: Sicilian cities

The COVID-19 pandemic has significantly influenced people’s lifestyles including their travel choices. The pandemic resulted in placing restrictions in travelling throughout Italy due to the obligatory need for social distancing and changes in public transport services. City residents changed their mobility patterns and started using their private vehicles more often instead of public transport, while choosing to walk or cycle for short distance trips. Governments and local authorities encouraged citizens to use sustainable travel modes, particularly walking, during the pandemic period. However, the high number of infections and deaths, especially in Italy, has strongly influenced the propensity of walking due to the emotional aspects of travelling. This paper presents a statistical analysis based on data gathered through a questionnaire in urban areas of Sicily focusing on travel by walking for either leisure or work. The evaluation of negative emotions that people who habitually walk for short distances in the study areas is the main focus of the present work.The data indicated a variation between three emotions: anxiety, stress, and fear. These emotions had a potential to influence people’s daily life and, as a result, their travel habits.

Nutrition and Water

Water has numerous functions necessary for survival including cellular homeostasis, solvent properties for dissolving ions and solutes, thermoregulation, and transport of waste and nutrients. Despite the established beneficial role of water in skin physiology, the optimal methods for skin hydration and requirements for daily water consumption remain elusive. This review summarizes the cellular and molecular biology of skin hydration, the debate and current recommendations of daily water requirements, and the latest research on interventions to improve skin hydration by both internal and external means of water exposure. We also explore the chemical properties of water, such as the concept of water "hardness" and environmental pollutants, and their impact on skin physiology.

Food Myths or Food Facts? Study about Perceptions and Knowledge in a Portuguese Sample

Food myths are nutritional concepts poorly justified or even contradict existing scientific evidence that individuals take as the truth. Knowledge in nutrition is an important tool in tackling misinformation and in the promotion of adequate food choices. This study aimed to investigate the beliefs and perceptions of a sample of the Portuguese population regarding a series of food myths and facts, evaluating, consequently, the level of knowledge and the main sources of information. The research was conducted on a sample of 503 participants, using a questionnaire disclosed online, by email, and social networks, between May and June of 2021. Thirty statements, some true and others false, were analyzed to assess people's perceptions. Based on the respondents' answers, a score was calculated for each statement, allowing to differentiate the correct (positive score) from incorrect (negative score) perceptions. The results showed that most statements obtained positive scores, corresponding to correct perceptions. Moreover, the level of knowledge was measured, being very high for 21.7% of the participants and high for 42.1%. The main sources where the participants acquire nutritional information are scientific journals (43.3%), website of the Portuguese General Health Office (DGS) (31.4%), and technical books (31.0%), which is concordant with the level of trust in these sources. Hence, it was concluded that, despite the levels of nutritional knowledge, there are still several food myths that need to be debunked, through the proper channels, in order to promote healthy, balanced, and adequate eating behaviors.

Dehydration and Headache

PURPOSE OF REVIEW

We define dehydration and its relationship to pain physiology including both primary and secondary headache disorders.

RECENT FINDINGS

Intravenous fluids administered for acute migraine attacks in an emergency department setting have not been shown to improve pain outcomes. However, increased intravascular volume before diagnostic lumbar puncture may reduce the frequency of post-lumbar puncture headache from iatrogenic spinal fluid leak. Maintenance of euhydration can help treat orthostatic and "coat-hanger" headache due to autonomic disorders. Similarly, prevention of fluid losses can mitigate secondary headaches provoked by dehydration such as cerebral venous thrombosis or pituitary apoplexy. Dehydration alone may cause headache, but oftentimes exacerbates underlying medical conditions such as primary headache disorders or other conditions dependent on fluid balance.