Olga Malisova

The water balance questionnaire: design, reliability and validity of a questionnaire to evaluate water balance in the general population

There is a need to develop a questionnaire as a research tool for the evaluation of water balance in the general population. The water balance questionnaire (WBQ) was designed to evaluate water intake from fluid and solid foods and drinking water, and water loss from urine, faeces and sweat at sedentary conditions and physical activity. For validation purposes, the WBQ was administrated in 40 apparently healthy participants aged 22–57 years (37.5% males). Hydration indices in urine (24 h volume, osmolality, specific gravity, pH, colour) were measured through established procedures. Furthermore, the questionnaire was administered twice to 175 subjects to evaluate its reliability. Kendalls τ-b and the Bland and Altman method were used to assess the questionnaires validity and reliability. The proposed WBQ to assess water balance in healthy individuals was found to be valid and reliable, and it could thus be a useful tool in future projects that aim to evaluate water balance.

Water Intake and Hydration Indices in Healthy European Adults: The European Hydration Research Study (EHRS)

Hydration status is linked with health, wellness, and performance. We evaluated hydration status, water intake, and urine output for seven consecutive days in healthy adults. Volunteers living in Spain, Germany, or Greece (n = 573, 39 ± 12 years (51.1% males), 25.0 ± 4.6 kg/m2 BMI) participated in an eight-day study protocol. Total water intake was estimated from seven-day food and drink diaries. Hydration status was measured in urine samples collected over 24 h for seven days and in blood samples collected in fasting state on the mornings of days 1 and 8. Total daily water intake was 2.75 ± 1.01 L, water from beverages 2.10 ± 0.91 L, water from foods 0.66 ± 0.29 L. Urine parameters were: 24 h volume 1.65 ± 0.70 L, 24 h osmolality 631 ± 221 mOsmol/kg Η2Ο, 24 h specific gravity 1.017 ± 0.005, 24 h excretion of sodium 166.9 ± 54.7 mEq, 24 h excretion of potassium 72.4 ± 24.6 mEq, color chart 4.2 ± 1.4. Predictors for urine osmolality were age, country, gender, and BMI. Blood indices were: haemoglobin concentration 14.7 ± 1.7 g/dL, hematocrit 43% ± 4% and serum osmolality 294 ± 9 mOsmol/kg Η2Ο. Daily water intake was higher in summer (2.8 ± 1.02 L) than in winter (2.6 ± 0.98 L) (p = 0.019). Water intake was associated negatively with urine specific gravity, urine color, and urine sodium and potassium concentrations (p < 0.01). Applying urine osmolality cut-offs, approximately 60% of participants were euhydrated and 20% hyperhydrated or dehydrated. Most participants were euhydrated, but a substantial number of people (40%) deviated from a normal hydration level.

Estimations of water balance after validating and administering the water balance questionnaire in pregnant women

Abstract Dehydration during pregnancy may be harmful for the mother and fetus; thus our objective was to understand whether pregnant women balance water intake and loss. The Water Balance Questionnaire (WBQ) was modified to reflect pregnancy (WBQ-P). Validation was performed using 3-day diaries (n = 60) and hydration indices in urine (osmolality, specific gravity, pH and color, n = 40). The WBQ-P was found valid according to Kedhal τ-b coefficient agreement. The WBQ-P was administered to 95, 100 and 97 women per trimester, in Greece. Median (IQR) water balance, intake and loss were, respectively, 203 (−577, 971), 2917 (2187, 3544) and 2658 (2078, 3391) ml/day; these did not differ among the trimesters or between pregnant and non-pregnant women. However, more pregnant women were falling in the higher quartiles of water balance distribution. No differences in sources of water intake were identified except that women in the third trimester had lower water intake from beverages.

Influence of Physical Activity and Ambient Temperature on Hydration: The European Hydration Research Study (EHRS)

This study explored the effects of physical activity (PA) and ambient temperature on water turnover and hydration status. Five-hundred seventy three healthy men and women (aged 20–60 years) from Spain, Greece and Germany self-reported PA, registered all food and beverage intake, and collected 24-h urine during seven consecutive days. Fasting blood samples were collected at the onset and end of the study. Food moisture was assessed using nutritional software to account for all water intake which was subtracted from daily urine volume to allow calculation of non-renal water loss (i.e., mostly sweating). Hydration status was assessed by urine and blood osmolality. A negative association was seen between ambient temperature and PA (r = −0.277; p < 0.001). Lower PA with high temperatures did not prevent increased non-renal water losses (i.e., sweating) and elevated urine and blood osmolality (r = 0.218 to 0.163 all p < 0.001). When summer and winter data were combined PA was negatively associated with urine osmolality (r = −0.153; p = 0.001). Our data suggest that environmental heat acts to reduce voluntary PA but this is not sufficient to prevent moderate dehydration (increased osmolality). On the other hand, increased PA is associated with improved hydration status (i.e., lower urine and blood osmolality).

Water Intake in a Sample of Greek Adults Evaluated with the Water Balance Questionnaire (WBQ) and a Seven-Day Diary

Awareness on the importance of hydration in health has created an unequivocal need to enrich knowledge on water intake of the general population and on the contribution of beverages to total water intake. We evaluated in the past water intake in a sample of Greek adults using two approaches. In study A, volunteers completed the Water Balance Questionnaire (WBQ), a food frequency questionnaire, designed to evaluate water intake (n = 1092; 48.1% males; 43 ± 18 years). In study B, a different population of volunteers recorded water, beverage, and food intake in seven-day diaries (n = 178; 51.1% males; 37 ± 12 years). Herein, data were reanalyzed with the objective to reveal the contribution of beverages in total water intake with these different methodologies. Beverage recording was grouped in the following categories: Hot beverages; milk; fruit and vegetable juices; caloric soft drinks; diet soft drinks; alcoholic drinks; other beverages; and water. Total water intake and water intake from beverages was 3254 (SE 43) mL/day and 2551 (SE 39) mL/day in study A; and 2349 (SE 59) mL/day and 1832 (SE 56) mL/day in study B. In both studies water had the highest contribution to total water intake, approximately 50% of total water intake, followed by hot beverages (10% of total water intake) and milk (5% of total water intake). These two approaches contribute information on water intake in Greece and highlight the contribution of different beverages; moreover, they point out differences in results obtained from different methodologies attributed to limitations in their use.

Evaluation of Drinks Contribution to Energy Intake in Summer and Winter

All drinks hydrate and most also provide nutrients and energy. Our objective was to evaluate the contribution of drinks to total energy intake in summer and winter. Data were obtained using the Water Balance Questionnaire (WBQ) from a sample of the general population in Athens, Greece (n = 984), 473 individuals (42 ± 18 years) in summer and 511 individuals (38 ± 20 years) in winter stratified by sex and age. The WBQ embeds a semi-quantitative food frequency questionnaire of 58 foods and the Short International Physical Activity Questionnaire. Data were analyzed for the contribution of drinks to total energy intake. In winter, total energy intake was 2082 ± 892 kcal/day; energy intake from drinks was 479 ± 286 kcal/day and energy expenditure 1860 ± 390 kcal/day. In summer, total energy intake was 1890 ± 894 kcal/day, energy intake from drinks 492 ± 499 kcal/day and energy expenditure 1830 ± 491 kcal/day. Energy intake from drinks in summer was higher than in winter (p < 0.001) and in men higher than in women in both seasons (p < 0.001 in summer, p = 0.02 in winter). Coffee, coffee drinks, milk, chocolate milk and alcoholic drinks contributed approximately 75% of energy from drinks. Fruit juice and sugar-sweetened drinks, including soft drinks and fruit juice based drinks, were consumed less frequently contributing up to 25% of drink energy intake. Drinks contribute approximately 1/4 of total energy intake depending on the energy content of the drink and frequency of consumption. Coffee, dairy and alcoholic drinks were the main energy contributors.

Sodium and Potassium Intake from Food Diaries and 24-h Urine Collections from 7 Days in a Sample of Healthy Greek Adults

Objective The main objective of the present study was to evaluate sodium and potassium intake, employing 24 h and spot urine samples and food diaries for seven consecutive days. Methods For seven consecutive days subjects recorded their food and drink intakes, and recorded and collected all urinations. Food sodium and potassium intake were analyzed in 24- and 6-h intervals from wake-up time. Urine indices were analyzed in first morning, 24- and 6-h intervals samples over the day from wake-up time. The study took place in Agricultural University of Athens, Greece. In total, 163 healthy subjects (age 39 ± 12 years; 74 females) were enrolled in the study. Results Mean urine sodium excretion was 2,803.3 ± 1,249.0 mg/day (121.9 ± 54.3 mmol/day) and mean urine potassium excretion was 2,152.2 ± 913.3 mg/day (55.2 ± 23.4 mmol/day). The highest potassium concentration was measured in the afternoon, while the lowest sodium concentration was measured in the overnight 6-h interval. Food sodium intake was 1,983.2 ± 814.1 mg/day and food potassium was 2,264.5 ± 653.3 mg/day. The sources that contribute most in food sodium intake are dairy products 24%, breads 22%, and savory snacks 17%. Conclusion Strategies should encourage the Greek population to moderate sodium intake and promote potassium intake, thus adopting a healthier dietary and lifestyle pattern.

Water intake and hydration indices in healthy adults; the European Hydration Research Study (EHRS).

9 ses which also supply additional energy and nutrients, such as fresh pressed fruit and vegetable juices, milk, soya and cereal based drinks, soups, gazpacho, etc. Finally, the fourth level includes sugar sweetened beverages which are recommended to be occasionally consumed. There is no evidence to support the contribution for hydration purposes of alcoholic beverages, including fermented beverages such as wine, cava and beer and therefore, such drinks are not included in the Healthy Hydration Pyramid.