Journal of Human Nutrition and Dietetics
PUBLIC HEALTH NUTRITION AND EPIDEMIOLOGY Water intakes and dietary sources of a nationally representative sample of Irish adults L. O’Connor,*† J. Walton* & A. Flynn* *School of Food and Nutritional Sciences, University College Cork, Cork, Ireland †MRC Epidemiology Unit, University of Cambridge, Institute of Metabolic Science, Cambridge, UK
Keywords adults, beverage, fluid, water. Correspondence J. Walton, University College Cork, Room 107, Food Science Building, Western Road, Cork, Ireland. Tel.: +353 21 490 3387 Fax: +353 21 427 0244 E-mail: [email protected] How to cite this article O’Connor L., Walton J. & Flynn A. (2014) Water intakes and dietary sources of a nationally representative sample of Irish adults. J Hum Nutr Diet. 27, 550–556 doi:10.1111/jhn.12189
Abstract Background: Despite evidence that even mild dehydration is associated with various morbidities, water intake estimates in free-living populations are lacking. The present study aimed to estimate water intakes and dietary sources in a nationally representative sample of the Irish adult population. Methods: A 4-day semi-weighed food record was used to collect dietary intake data from 1500 free-living adults aged 18–90 years in the Irish National Adult Nutrition Survey (NANS) (2008–2010) from which water intake was estimated. To enable fluid intake estimation, additional questions on how water and milk were consumed were incorporated. Total water intake was calculated as drinking water plus water from other beverages and food moisture. Results: The mean (SD) daily total water intake for Irish adults was 2.31 (0.92) L day–1 [males 2.52 (1.00) L day–1; females 2.09 (0.79) L day–1]. Intakes were lowest in elderly adults, as well as in those with less education, a lower social class, less energy expenditure and a higher body mass index and body fat percentage. In total, 67% of water came from beverages and 33% came from food moisture. Alcoholic beverages and teas individually contributed to total water intake in amounts similar to the drinking water contribution. Conclusions: These data may be used as a foundation for further research in the area of the effect of under consumption of water on health outcomes to guide public health messages regarding adequate water intakes.
Introduction The human body requires a minimum intake of water to sustain life. Evidence exists that even mild dehydration is associated with various morbidities. The most consistent evidence is for low water intake and urolithiasis (Armstrong, 2012), although chronic mild dehydration has been suggested as a possible pathogenic factor in a variety of disease, including urinary tract infection, hypertension and stroke (Manz, 2007). Evidence also exists for an association between increased drinking water intake and weight loss (Stookey et al., 2008; Dennis et al., 2009; Daniels & Popkin, 2010) and the replacement of plain water intake with other beverages, in particular sugar sweetened beverages, has been linked to obesity and type 2 diabetes (Vartanian et al., 2007; Hu & Malik, 2010; 550
Malik et al., 2010; Tate et al., 2012). Despite this evidence, there is a paucity of estimates of water intake and dietary sources in free-living populations. The requirement for water intake varies greatly between individuals and a number of characteristics are known to have an effect, including age, sodium and protein intakes, climate and physical activity levels (Institute of Medicine, 2004). According to the World Health Organization (WHO), the required amount of fluid (including water ingested from food) to maintain hydration for average adults under average conditions is 2.9 L day–1 for males and 2.2 L day–1 for females. Adequate water intakes (from drinking water, beverages of all kinds and food moisture) have been proposed by the European Food Safety Authority (EFSA) of 2.5 L day–1 for adult males and 2.0 L day–1 for adult females (EFSA, 2010). These are ª 2013 The British Dietetic Association Ltd.
L. O’Connor et al.
derived from observed intakes in population groups based on national consumption surveys. However, many national surveys and larger epidemiological study designs have focused on food intake and, as such, are not adequately designed to estimate water intake. In the Irish National Adult Nutrition Survey (NANS), an equal emphasis was placed on the recording of foods and beverages, and additional data were recorded on how milk and water were consumed. Using these detailed data, we aimed to estimate water intakes and dietary sources in a nationally representative sample of Irish adults. Materials and methods The National Adult Nutrition Survey (NANS) was carried out to establish a database of habitual food and beverage consumption in a representative sample of Irish adults aged >18 years, comprising 1500 adults (740 males, 760 females). A detailed survey methodology is available elsewhere (http://www.iuna.net) and only a concise overview of methodology pertinent to the present study is provided below. Ethical approval was obtained from the Clinical Research Ethics Committee of the Cork Teaching Hospitals, University College Cork and the Human Ethics Research Committee of University College Dublin. Eligible participants were adults who were free-living, who were not pregnant or breast feeding and who were resident in the Republic of Ireland. The fieldwork phase of the NANS was carried out between October 2008 and April 2010, providing a seasonal balance to the data collection. A sample of adults was randomly selected from a database of names and addresses held by Data Ireland (http:// www.dataireland.ie). An introductory letter and information leaflet were posted to each individual selected from the database. A researcher called to potential participants’ homes to introduce the survey and invite participation. If the individual agreed to participate, a consent form was signed and the survey commenced. If the individual was not at home, the researcher called on three more occasions on different days and at different times, before deeming them ineligible. The final response rate for the survey was 60%. Analysis of the demographic features in this sample has shown it to be a representative sample of Irish adults with respect to age, sex, social class and geographical location when compared with census data. A 4-day semi-weighed dietary record was used to collect food and beverage intake data. Participants received a training visit in which they were provided with digital scales (Tanita, Japan) and a food diary and were instructed how to weigh and record all food and beverages consumed. An example using the participant’s own food and beverage intake was completed. Two detailed ª 2013 The British Dietetic Association Ltd.
Water intakes in Irish adults
reviews of the diary were carried out by researchers to ensure completeness and to clarify, where needed, food and beverage descriptors. Nutrient intakes (including energy and water) were estimated using WISP© (Tinuviel Software, Anglesey, UK), which included data from food composition tables, McCance and Widdowson’s, The Composition of Foods, 6th Edition (Food Standards Agency, 2002) and 5th Edition (Holland et al., 1995), plus supplemental volumes (Holland et al., 1988, 1989, 1991, 1992a,b, 1993; Chan et al., 1994, 1996a,b), and The Irish Food Composition Database (Black et al., 2011). Where recipes had been created for dishes not listed in composition tables, the water content was calculated using listed water content for individual ingredients and adjusting for water loss during cooking from McCance and Widdowson’s, The Composition of Foods, 6th Edition (Food Standards Agency, 2002). Anthropometric measurements were taken by trained researchers in accordance with standardised methods. Sociodemographic and lifestyle data were self-reported in questionnaires. Energy expenditure was measured using a validated questionnaire: the EPIC Physical Activity Questionnaire (Wareham et al., 2002). To enable fluid intake estimation, additional questions on how water and milk were consumed were incorporated. The researcher identified whether milk was consumed as a beverage, served on a breakfast cereal, or as a component of tea, coffee or other hot drinks. Milk added to breakfast cereals was then reincorporated with the breakfast cereal to reflect the food as it was served. For water, the researcher identified whether the water was consumed as drinking water, as part of a soft drink, or as a component of tea, coffee or other hot drinks. This enabled the estimation of drinking water. Brands of food and beverages consumed were also recorded, allowing the identification of bottled water from tap water. Total water intake was calculated as drinking water plus water from other beverages and food moisture. Statistical analyses were conducted using SPSS, version 15.0 (SPSS Inc., Chicago, IL, USA). Data are presented as the mean (SD), median and interquartile range, or as a percentage. Total water intake was collapsed into quartiles. Sociodemographic and anthropometric characteristics were reported across quartiles. Differences across quartiles of total water intake were examined using one-way analysis of variance (ANOVA) or Kruskal–Wallis tests for nonparametric data. Total water intakes (mL day 1, mL kg 1 day 1 and mL kJ day 1) and sources (mL day 1) were estimated and reported by sex and age group. Differences across age groups within sex were assessed using ANOVA or Kruskal– Wallis tests. Differences between sexes were assessed using independent-samples t-tests or, where data were deemed non-normal, Mann–Whitney U-tests. 551
L. O’Connor et al.
Water intakes in Irish adults
Results Total water intake (mL day 1) was higher in males, younger adults, those with higher education levels, those who consumed alcohol more frequently, those with higher
energy expenditure levels (metabolic equivalent tasks h–1 week–1] (P < 0.001) and those with a higher social class (P = 0.007) (Table 1). Mean body mass index (kg m–2) and body fat (%) were lowest in the highest quartile of total water intake (mL day 1). Smoking status
Table 1 Sociodemographic and anthropometric characteristics by quartile of total water intakes (mL day 1) in adults (n = 1500): The National Adult Nutrition Survey, Ireland Total water intake (mL day 1) Q1 (319–1693) Total water intake 1304 (301)* (mL day 1) Total water intake 0.22 (0.07) (mL kJ day 1) Total water intake 17.9 (5.4) (mL kg 1 day 1) Males (%) 37 Age (years) 46 (18) Winter (%)† 48 Education (%) Primary 42 Intermediate 29 Secondary 26 Tertiary 19 Social class Professional/ 19 managerial Non-manual 27 skilled Manual skilled 28 Semi-skilled/ 29 unskilled (includes students) Current smokers (%) 30 Frequency of consumption of alcoholic beverages More than once 16 per week Once or twice 25 per fortnight Infrequently or 35 never Body mass index 28.0 (5.8) (kg m–2) Body fat (%) 32.2 (9.4) Energy 59.6 (19.3–110.1)‡ expenditure (work and recreational activities) MET h week–1
Q2 (1693–2161)
Q3 (2162–2887)
Q4 (2780–6655)
P
1915 (137)
2450 (175)
3556 (730)
0.000
0.26(0.07)
0.29 (0.07)
0.38 (0.12)
0.000
25.9 (5.41)
33.3 (6.8)
46.0 (12.2)
0.000
44 47 (18) 56
53 44 (16) 57
64 40 (15) 56
0.000 0.000 0.058
22 24 28 25
19 23 21 29
17 24 25 28
0.000
27
28
26
0.007
24
25
23
25 20
24 21
23 29
24
18
28
0.017
25
24
36
0.000
25
29
21
26
23
16
27.2 (4.9)
26.4 (4.4)
26.8 (4.6)
0.000
30.3 (8.6) 69.7 (33.6–107.0)
27.8 (8.3) 86.2 (47.1–130.2)
26.6 (8.8) 96.6 (58.8–151.0)
0.000 0.000
*Mean (SD) (all values). Winter: surveyed September to February. ‡ Median (interquartile range) (all such values). P denotes differences across quartiles of total water intake, analysis of variance or Kruskal–Wallis for nonparametric data. Q, quartile, MET, metabolic equivalent tasks. †
552
ª 2013 The British Dietetic Association Ltd.
L. O’Connor et al.
Water intakes in Irish adults
differed significantly with quartile of water intake but no trend in either direction was obvious. Water intake for Irish adults is tabulated by sex and age group in Table 2. Total daily water intake was 2521 mL in men and 2097 mL in women. Total water intake decreased with increasing age group in men (P = 0.000) and did not differ significantly with age group in women (P = 0.143). When adjusted for body weight (kg), there was a higher intake in younger men (18–35 years) than any other age category. No differences were observed between men and women or between different age categories for women. When adjusted for energy intake, women (18–90 years) had higher intakes than men and no differences were observed across age category in either men or women. Sources of water intake are presented in Table 3. Total water intake in Irish males comprised 67% fluids (16% drinking water, 51% other beverages) and 33% food moisture. In women, total water intake comprised 67% fluids (20% drinking water, 47% other beverages) and 33% food moisture. Mean intakes of drinking water decreased with age in both men (P = 0.000) and women (P = 0.001). Within other beverages, the main contributors to water intake in men were alcoholic beverages followed by tea and, in women, the main contributors were tea followed by alcoholic beverages. The proportion of total water intake sourced from food moisture increased with age in women (P = 0.000) but not men. Discussion Total water intakes in the Irish population are similar to the adequate intakes proposed by the EFSA (2010). Intakes were higher in men than in women and were lowest in elderly adults. There was also large variation in intakes within sex- and age-specific groups and, although
likely to be largely a result of individual need variation and response to other stimuli (e.g. temperature and physical activity), the intakes of some participants were low compared to the mean intakes in this population. Because mild dehydration has been associated with various morbidities (Manz, 2007; Armstrong, 2012), this warrants further examination, including in prospective studies. The importance of the source of water intake in the diet is understudied. Various sources of total water intake were shown to differ in their association with dietary characteristics and body weight in a study of US adults (Kant et al., 2009). In the present study, the larger proportion of total water (67%) came from beverage sources and, although drinking water was the single most consumed beverage, the majority of the contribution came from other beverages. Beverages such as milk are a source of important nutrients (Irish Universities Nutrition Alliance, 2011); however, other beverages, such as alcoholic beverages (WHO, 2011) and sugar sweetened beverages (Malik & Hu, 2012; Bray & Popkin, 2013), have been shown to have a detrimental impact on health. Although the effects of increased consumption of certain beverages on health outcomes have been well documented, there has been little research into the effect of substitution of plain water for these other beverages. A systematic review of the impact of water intake on energy intake and weight status examined the data comparing beverage consumption in comparison with drinking water consumption (Daniels & Popkin, 2010). They reported sparse and inconsistent data other than for sugar and artificially sweetened beverages, where sugar sweetened beverages versus water before a single meal equated to a 7.8% higher total energy intake and artificially sweetened beverages had no impact on energy intake among adults. As such, not all beverage sources of water are equal in terms of nutritional and health outcomes. In the present study, the contribution of
Table 2 Total water intakes in adults (n = 1500) by sex and age group: The National Adult Nutrition Survey, Ireland Mean (SD)
Mean (SD)
Mean (SD)
Mean (SD)
Mean (SD)
Age-group
18–90 years
18–35 years
36–50 years
51–64 years
65–90 years
P
Men Total water intake (mL day 1) Total water intake (mL kg 1 day 1) Total water intake (mL kJ day 1)
(n = 740) 2521 (1002)* 30.6 (12.7) 0.26 (0.10)*
(n = 276) 2817a (1128) 35.1a (14.6) 0.26 (0.10)
(n = 205) 2443b (925) 28.7b (10.9) 0.26 (0.10)
(n = 153) 2403b (767) 27.4b (9.5) 0.26 (0.10)
(n = 106) 2071c (870) 26.4b (10.6) 0.26 (0.10)
0.000 0.000 0.408
Women
(n = 760)
(n = 255)
(n = 232)
(n = 153)
(n = 120)
2097 (787) 31.3 (13.2) 0.31 (0.12)
2072 (806) 32.0 (13.1) 0.29 (0.12)
2157 (818) 31.7 (13.6) 0.31 (0.10)
2147 (772) 30.9 (13.4) 0.31 (0.10)
1968 (685) 29.7 (12.5) 0.31 (0.10)
1
Total water intake (mL day ) Total water intake (mL kg 1 day 1) Total water intake (mL kJ day 1)
0.143 0.458 0.139
mL/kg/day, mL per kg of total body weight per day: mL/kcal/day, mL per kcal of total energy intake per day. P & abc denote significant differences across age group within gender, ANOVA. *Denotes significantly different from females (18–90 years) at P < 0.05, independent samples t-test.
ª 2013 The British Dietetic Association Ltd.
553
554
121
Bottled
132
48
Milk
Fruit juices &
746
2
32
(269)*
(24)
(112)
(160)
(87)*
(155)
(388)*
(234)*
(653)
(767)*
(283)*
(581)*
(634)
(946)*
741
3
47
158
62
131
208
92
609
1319
179
578
757
2076
(286)
(23)
(121)a
737
4
30
87
42
(102)a
(180)a
141
446
(173)
193
(284)a
356
(211)a
(808)a
1312
128
(338)a
(904)a
267
395
1706
2443
(703)a
(726)
a
(1072)a
(1128)
(234)
(34)
(126)b
(153)b
(84)b
(167)
(368)b
(272)b
(557)b
(716)a
(312)b
(460)b
(535)
b
(869)b
(925)
755
1
24
50
39
134
606
142
333
1335
68
246
313
1648
2403
Mean
(261)
(7)
(105)b
(119)c
(72)b
(131)
(418)c
(235)c
(498)b
(623)a
(167)b
(491)b
(536)
b
(706)b
(767)
(SD)
765
1
8
22
38
112
587
96
225
1095
29
183
211
1307
2071
Mean c
(298)
(9)
(48)b
(103)d
(60)b
(104)
(368)bc
(182)ac
(416)b
(631)b
(118)c
(360)b
(381)
c
(781)c
(870)
(SD)
(n = 106)
0.684
0.489
0.000
0.000
0.025
0.136
0.000
0.000
0.000
0.007
0.000
0.000
0.000
0.000
0.000
P
637
4
28
74
39
99
476
115
124
976
159
325
483
1460
2097
Mean
(237)
(24)
(124)
(148)
(65)
(121)
(417)
(183)
(230)
(510)
(350)
(465)
(535)
(706)
(787)
(SD)
(n = 760)
560
1
51
146
46
76
307
86
187
923
216
373
589
1512
2072
Mean
(200)a
(7)
(175)a
(202)a
616
5
22
54
35
111
(88)a (72)a
543
146
131
1071
149
320
469
1540
2157
Mean
(215)b
(34)
(111)b
(111)b
(62)ab
(139)b
(496)b
(207)b
(214)a
(610)ac
(332)b
(484)
(517)
b
(754)a
(818)
(SD)
(n = 232)
years
36–50
(283)a
(159)a
(306)a
(463)ab
(425)a
(498)
(607)
a
(734)a
(806)
(SD)
(n = 255)
years
18–35
Superscript lowercase letters denote significant differences across age group within sex (analysis of variance or Kruskal–Wallis test for nonparametric data). *Denotes significantly different from females (18–90 years) at P < 0.05 (Mann–Whitney U-test).
Food moisture
barley cup)
shakes,
protein
chocolate,
drinking
Other (e.g.
drinks
fruit juice
Cordials &
beverages
Carbonated
97
410
smoothies
131
Teas
427
Coffees
beverages
Alcoholic
beverages
Other
1288
366
Tap water
water
487
1775
2817
(SD)
(n = 153)
b
(1002)*
Mean
(n = 205)
b
2521
Drinking water
Fluids
(mL day 1)
intake
Total water
a
Mean
(SD)
Mean
(SD)
(n = 276)
years
(n = 740)
years
65–90 18–90
years
51–64
years
years years
18–35
18–90 36–50
Women
Men
Table 3 Sources of total water intake (mL day 1) in adults (n = 1500) by sex and age group: The National Adult Nutrition Survey, Ireland
739
4
16
35
29
98
586
127
83
986
131
292
423
1409
2147
Mean
(273)c
(19)
(72)b
(86)c
(55)b
(131)ab
(441)b
(198)b
(139)b
(470)a
(272)b
(424)
(478)
a
(647)a
(772)
(SD)
(n = 153)
years
51–64
710
7
5
9
43
123
566
99
26
893
91
274
365
1258
1968
Mean
(234)bc
(28)
(24)b
(36)d
(66)ac
(122)c
(346)b
(155)ab
(55)c
(406)a
(271)c
(394)
(433)c
(572)b
(685)
(SD)
(n = 120)
years
65–90
0.000
0.085
0.000
0.000
0.025
0.000
0.000
0.000
0.000
0.019
0.000
0.213
0.001
0.001
0.285
P
Water intakes in Irish adults L. O’Connor et al.
ª 2013 The British Dietetic Association Ltd.
L. O’Connor et al.
alcoholic beverages to water intakes was high compared to other individual beverages, in particular in young men (those aged 18–35 years). The effects of consuming alcoholic beverages as a source of water may have a negative impact on health additional compared to that from alcohol consumption, and warrant further investigation. Furthermore, in this sample, intakes of tea in men and women and alcoholic beverages in men each contributed almost as much to total water intakes as drinking water did. Because alcoholic beverages and tea are diuretics, the treatment of these sources of total water commensurate with other beverages may not be appropriate. Food moisture is an important source of total water intake in the Irish diet, accounting for 33% of total water intake. The water content of food is one of the major determinants of dietary energy density. Dietary energy density has been positively associated with obesity (Mendoza et al., 2007), diabetes (Wang et al., 2008) and inversely associated with dietary quality (Patterson et al., 2010; O’Connor et al., 2013). Promoting an increased intake of foods with high water content to achieve adequate intakes of water is in keeping with current public health guidelines on reducing the consumption of energy dense foods. This large contribution of food moisture along with the between and within sex and age group variation suggests that assessing fluid intake without considering food intake would provide misleading results. The strengths of the present study include the national representative nature of the data, the detailed food and drink consumption data that were collected at brand level, and the high percentage of intake data that were weighed and not estimated. Also, because intakes were prospectively recorded, recall bias is precluded. This method for calculating water intake also has strengths, including the ability to calculate water in beverages and food moisture, as well as its contribution to water intake in this population; the recording of brand that allows intakes of tap water and bottle water to be distinguished; and the inclusion of questions to determine how milk and water were consumed, therefore correctly identifying whether they should be classified as a food or a beverage. Because water intakes were estimated from selfreported food diaries, estimates may be affected by participant under-, over- and selective-reporting of intakes and portion sizes. However, participants were interviewed and trained in diary completion by qualified nutritionists, diaries were reviewed and suspected gaps in participant’s food records were questioned. A limitation of this method includes the possibility that prompting participants to remember their water intake may have changed their behaviour; however, during training, researchers were made aware of this and trained to be neutral in attitudes towards a participant’s intakes. ª 2013 The British Dietetic Association Ltd.
Water intakes in Irish adults
In summary, we found that mean total water intakes were similar to proposed adequate intakes; some participants had very low water intakes; there was a high contribution of other beverages (in particular alcoholic beverages to total water intakes); and food moisture is an important source of water intake. These detailed estimates can be used as a foundation for further research, a baseline for quantitative recommendations and to guide public health messages regarding adequate water intakes.
Acknowledgments We would like to thank all the participants and staff of the National Adult Nutrition Survey for their time and contribution.
Conflict of interests, source of funding and authorship The authors declare that there are no conflicts of interest. The project was funded by the Irish Department of Agriculture, Food and the Marine and the Health Research Board under their joint Food for Health Research Initiative (2007–2012). L’OC and JW derived the water intakes, carried out the analysis, drafted the initial manuscript and are responsible for the accuracy of the data. AF is a principal investigator of the National Adult Nutrition Survey and provided insight on data analysis and contributed to the manuscript. All authors contributed to critical revisions and have read and approved the final manuscript submitted for publication.
References Armstrong, L.E. (2012) Challenges of linking chronic dehydration and fluid consumption to health outcomes. Nutr. Rev. 70(Suppl. 2), S121–S127. Black, L.J., Ireland, J., Møller, A., Roe, M., Walton, J., Flynn, A., Finglas, P.M. & Kiely, M. (2011) Development of an on-line Irish food composition database for nutrients. J. Food Comp Anal. 24, 1017–1023. Bray, G.A. & Popkin, B.M. (2013) Calorie-sweetened beverages and fructose: what have we learned 10 years later. Pediatr. Obes. 4, 242–248. Chan, W., Brown, J. & Buss, D.H. (1994) Miscellaneous Foods. Fourth Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Chan, W., Brown, J., Church, S.M. & Buss, D.H. (1996a) Meat Products and Dishes. Sixth Supplement to 5th Edition of
555
Water intakes in Irish adults
McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Chan, W., Brown, J., Lee, S. & Buss, D.H. (1996b) Meat, Poultry and Game. Fifth Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Daniels, M.C. & Popkin, B.M. (2010) Impact of water intake on energy intake and weight status: a systematic review. Nutr. Rev. 68, 505–521. Dennis, E.A., Flack, K.D. & Davy, B.M. (2009) Beverage consumption and adult weight management: a review. Eat. Behav. 10, 237–246. European Food Safety Authority. (2010) Scientific opinion on dietary reference values for water. EFSA J. 8, 1459. Food Standards Agency. (2002) McCance and Widdowson’s, The Composition of Foods, 6th edn. Cambridge: Food Standards Agency, Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1988) Cereals and Cereal Products. Third Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1989) Milk Products and Eggs. Fourth Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1991) Vegetables, Herbs and Spices. Fifth Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1992a) Fruit and Nuts. First Supplement to 5th edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Welch, A.A. & Buss, D.H. (1992b) Vegetable Dishes. Second Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Brown, J. & Buss, D.H. (1993) Fish and Fish products. Third Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Welch, A.A., Unwin, I.D., Buss, D.H., Paul, A.A. & Southgate, D.A.T. (1995) McCance & Widdowsons The Composition of Foods, 5th edn. London: Royal Society of Chemistry and Ministry of Agriculture, Fisheries and Food, HMSO. Hu, F.B. & Malik, V.S. (2010) Sugar-sweetened beverages and risk of obesity and type 2 diabetes: epidemiologic evidence. Physiol. Behav. 100, 47–54. Institute of Medicine. (2004) Institute of Medicine. Food and Nutrition Board. Panel on Dietary Reference Intakes for Electrolytes and Water: Dietary Reference Intakes for Water, Potassium, Sodium Chloride, and Sulfate.
556
L. O’Connor et al.
Irish Universities Nutrition Alliance. (2011) National Adult Nutrition Survey Summary Report. Irish Universities Nutrition Alliance. Kant, A.K., Graubard, B.I. & Atchison, E.A. (2009) Intakes of plain water, moisture in foods and beverages, and total water in the adult US population–nutritional, meal pattern, and body weight correlates: National Health and Nutrition Examination Surveys 1999-2006. Am. J. Clin. Nutr. 90, 655–663. Malik, V.S. & Hu, F.B. (2012) Sweeteners and risk of obesity and type 2 diabetes: the role of sugar-sweetened beverages. Curr. Diab. Rep. 12, 195–203. Malik, V.S., Popkin, B.M., Bray, G.A., Despres, J.P., Willett, W.C. & Hu, F.B. (2010) Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis. Diabetes Care 33, 2477–2483. Manz, F. (2007) Hydration and disease. J. Am. Coll. Nutr. 26, 535S–541S. Mendoza, J.A., Drewnowski, A. & Christakis, D.A. (2007) Dietary energy density is associated with obesity and the metabolic syndrome in US adults. Diabetes Care 30, 974–979. O’Connor, L., Walton, J. & Flynn, A. (2013) Dietary energy density and its association with the nutritional quality of the diet of children and teenagers. J. Nutr. Sci. 2, e10. Patterson, E., Warnberg, J., Poortvliet, E., Kearney, J.M. & Sjostrom, M. (2010) Dietary energy density as a marker of dietary quality in Swedish children and adolescents: the European Youth Heart Study. Eur. J. Clin. Nutr. 64, 356–363. Stookey, J.D., Constant, F., Popkin, B.M. & Gardner, C.D. (2008) Drinking water is associated with weight loss in overweight dieting women independent of diet and activity. Obesity (Silver Spring) 16, 2481–2488. Tate, D.F., Turner-Mcgrievy, G., Lyons, E., Stevens, J., Erickson, K., Polzien, K., Diamond, M., Wang, X. & Popkin, B. (2012) Replacing caloric beverages with water or diet beverages for weight loss in adults: main results of the Choose Healthy Options Consciously Everyday (CHOICE) randomized clinical trial. Am. J. Clin. Nutr. 95, 555–563. Vartanian, L.R., Schwartz, M.B. & Brownell, K.D. (2007) Effects of soft drink consumption on nutrition and health: a systematic review and meta-analysis. Am. J. Public Health 97, 667–675. Wang, J., Luben, R., Khaw, K.T., Bingham, S., Wareham, N.J. & Forouhi, N.G. (2008) Dietary energy density predicts the risk of incident type 2 diabetes The European Prospective Investigation of Cancer (EPIC)–Norfolk Study. Diabetes Care 31, 2120–2125. Wareham, N.J., Jakes, R.W., Rennie, K.L., Mitchell, J., Hennings, S. & Day, N.E. (2002) Validity and repeatability of the EPIC0Norfolk Physical Activity Questionnaire. Int. J. Epidemiol. 31, 168–174. World Health Organization. (2011) Global Status Report on Alcohol and Health 2011. Geneva: World Health Organization.
ª 2013 The British Dietetic Association Ltd.
Copyright of Journal of Human Nutrition & Dietetics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
PUBLIC HEALTH NUTRITION AND EPIDEMIOLOGY Water intakes and dietary sources of a nationally representative sample of Irish adults L. O’Connor,*† J. Walton* & A. Flynn* *School of Food and Nutritional Sciences, University College Cork, Cork, Ireland †MRC Epidemiology Unit, University of Cambridge, Institute of Metabolic Science, Cambridge, UK
Keywords adults, beverage, fluid, water. Correspondence J. Walton, University College Cork, Room 107, Food Science Building, Western Road, Cork, Ireland. Tel.: +353 21 490 3387 Fax: +353 21 427 0244 E-mail: [email protected] How to cite this article O’Connor L., Walton J. & Flynn A. (2014) Water intakes and dietary sources of a nationally representative sample of Irish adults. J Hum Nutr Diet. 27, 550–556 doi:10.1111/jhn.12189
Abstract Background: Despite evidence that even mild dehydration is associated with various morbidities, water intake estimates in free-living populations are lacking. The present study aimed to estimate water intakes and dietary sources in a nationally representative sample of the Irish adult population. Methods: A 4-day semi-weighed food record was used to collect dietary intake data from 1500 free-living adults aged 18–90 years in the Irish National Adult Nutrition Survey (NANS) (2008–2010) from which water intake was estimated. To enable fluid intake estimation, additional questions on how water and milk were consumed were incorporated. Total water intake was calculated as drinking water plus water from other beverages and food moisture. Results: The mean (SD) daily total water intake for Irish adults was 2.31 (0.92) L day–1 [males 2.52 (1.00) L day–1; females 2.09 (0.79) L day–1]. Intakes were lowest in elderly adults, as well as in those with less education, a lower social class, less energy expenditure and a higher body mass index and body fat percentage. In total, 67% of water came from beverages and 33% came from food moisture. Alcoholic beverages and teas individually contributed to total water intake in amounts similar to the drinking water contribution. Conclusions: These data may be used as a foundation for further research in the area of the effect of under consumption of water on health outcomes to guide public health messages regarding adequate water intakes.
Introduction The human body requires a minimum intake of water to sustain life. Evidence exists that even mild dehydration is associated with various morbidities. The most consistent evidence is for low water intake and urolithiasis (Armstrong, 2012), although chronic mild dehydration has been suggested as a possible pathogenic factor in a variety of disease, including urinary tract infection, hypertension and stroke (Manz, 2007). Evidence also exists for an association between increased drinking water intake and weight loss (Stookey et al., 2008; Dennis et al., 2009; Daniels & Popkin, 2010) and the replacement of plain water intake with other beverages, in particular sugar sweetened beverages, has been linked to obesity and type 2 diabetes (Vartanian et al., 2007; Hu & Malik, 2010; 550
Malik et al., 2010; Tate et al., 2012). Despite this evidence, there is a paucity of estimates of water intake and dietary sources in free-living populations. The requirement for water intake varies greatly between individuals and a number of characteristics are known to have an effect, including age, sodium and protein intakes, climate and physical activity levels (Institute of Medicine, 2004). According to the World Health Organization (WHO), the required amount of fluid (including water ingested from food) to maintain hydration for average adults under average conditions is 2.9 L day–1 for males and 2.2 L day–1 for females. Adequate water intakes (from drinking water, beverages of all kinds and food moisture) have been proposed by the European Food Safety Authority (EFSA) of 2.5 L day–1 for adult males and 2.0 L day–1 for adult females (EFSA, 2010). These are ª 2013 The British Dietetic Association Ltd.
L. O’Connor et al.
derived from observed intakes in population groups based on national consumption surveys. However, many national surveys and larger epidemiological study designs have focused on food intake and, as such, are not adequately designed to estimate water intake. In the Irish National Adult Nutrition Survey (NANS), an equal emphasis was placed on the recording of foods and beverages, and additional data were recorded on how milk and water were consumed. Using these detailed data, we aimed to estimate water intakes and dietary sources in a nationally representative sample of Irish adults. Materials and methods The National Adult Nutrition Survey (NANS) was carried out to establish a database of habitual food and beverage consumption in a representative sample of Irish adults aged >18 years, comprising 1500 adults (740 males, 760 females). A detailed survey methodology is available elsewhere (http://www.iuna.net) and only a concise overview of methodology pertinent to the present study is provided below. Ethical approval was obtained from the Clinical Research Ethics Committee of the Cork Teaching Hospitals, University College Cork and the Human Ethics Research Committee of University College Dublin. Eligible participants were adults who were free-living, who were not pregnant or breast feeding and who were resident in the Republic of Ireland. The fieldwork phase of the NANS was carried out between October 2008 and April 2010, providing a seasonal balance to the data collection. A sample of adults was randomly selected from a database of names and addresses held by Data Ireland (http:// www.dataireland.ie). An introductory letter and information leaflet were posted to each individual selected from the database. A researcher called to potential participants’ homes to introduce the survey and invite participation. If the individual agreed to participate, a consent form was signed and the survey commenced. If the individual was not at home, the researcher called on three more occasions on different days and at different times, before deeming them ineligible. The final response rate for the survey was 60%. Analysis of the demographic features in this sample has shown it to be a representative sample of Irish adults with respect to age, sex, social class and geographical location when compared with census data. A 4-day semi-weighed dietary record was used to collect food and beverage intake data. Participants received a training visit in which they were provided with digital scales (Tanita, Japan) and a food diary and were instructed how to weigh and record all food and beverages consumed. An example using the participant’s own food and beverage intake was completed. Two detailed ª 2013 The British Dietetic Association Ltd.
Water intakes in Irish adults
reviews of the diary were carried out by researchers to ensure completeness and to clarify, where needed, food and beverage descriptors. Nutrient intakes (including energy and water) were estimated using WISP© (Tinuviel Software, Anglesey, UK), which included data from food composition tables, McCance and Widdowson’s, The Composition of Foods, 6th Edition (Food Standards Agency, 2002) and 5th Edition (Holland et al., 1995), plus supplemental volumes (Holland et al., 1988, 1989, 1991, 1992a,b, 1993; Chan et al., 1994, 1996a,b), and The Irish Food Composition Database (Black et al., 2011). Where recipes had been created for dishes not listed in composition tables, the water content was calculated using listed water content for individual ingredients and adjusting for water loss during cooking from McCance and Widdowson’s, The Composition of Foods, 6th Edition (Food Standards Agency, 2002). Anthropometric measurements were taken by trained researchers in accordance with standardised methods. Sociodemographic and lifestyle data were self-reported in questionnaires. Energy expenditure was measured using a validated questionnaire: the EPIC Physical Activity Questionnaire (Wareham et al., 2002). To enable fluid intake estimation, additional questions on how water and milk were consumed were incorporated. The researcher identified whether milk was consumed as a beverage, served on a breakfast cereal, or as a component of tea, coffee or other hot drinks. Milk added to breakfast cereals was then reincorporated with the breakfast cereal to reflect the food as it was served. For water, the researcher identified whether the water was consumed as drinking water, as part of a soft drink, or as a component of tea, coffee or other hot drinks. This enabled the estimation of drinking water. Brands of food and beverages consumed were also recorded, allowing the identification of bottled water from tap water. Total water intake was calculated as drinking water plus water from other beverages and food moisture. Statistical analyses were conducted using SPSS, version 15.0 (SPSS Inc., Chicago, IL, USA). Data are presented as the mean (SD), median and interquartile range, or as a percentage. Total water intake was collapsed into quartiles. Sociodemographic and anthropometric characteristics were reported across quartiles. Differences across quartiles of total water intake were examined using one-way analysis of variance (ANOVA) or Kruskal–Wallis tests for nonparametric data. Total water intakes (mL day 1, mL kg 1 day 1 and mL kJ day 1) and sources (mL day 1) were estimated and reported by sex and age group. Differences across age groups within sex were assessed using ANOVA or Kruskal– Wallis tests. Differences between sexes were assessed using independent-samples t-tests or, where data were deemed non-normal, Mann–Whitney U-tests. 551
L. O’Connor et al.
Water intakes in Irish adults
Results Total water intake (mL day 1) was higher in males, younger adults, those with higher education levels, those who consumed alcohol more frequently, those with higher
energy expenditure levels (metabolic equivalent tasks h–1 week–1] (P < 0.001) and those with a higher social class (P = 0.007) (Table 1). Mean body mass index (kg m–2) and body fat (%) were lowest in the highest quartile of total water intake (mL day 1). Smoking status
Table 1 Sociodemographic and anthropometric characteristics by quartile of total water intakes (mL day 1) in adults (n = 1500): The National Adult Nutrition Survey, Ireland Total water intake (mL day 1) Q1 (319–1693) Total water intake 1304 (301)* (mL day 1) Total water intake 0.22 (0.07) (mL kJ day 1) Total water intake 17.9 (5.4) (mL kg 1 day 1) Males (%) 37 Age (years) 46 (18) Winter (%)† 48 Education (%) Primary 42 Intermediate 29 Secondary 26 Tertiary 19 Social class Professional/ 19 managerial Non-manual 27 skilled Manual skilled 28 Semi-skilled/ 29 unskilled (includes students) Current smokers (%) 30 Frequency of consumption of alcoholic beverages More than once 16 per week Once or twice 25 per fortnight Infrequently or 35 never Body mass index 28.0 (5.8) (kg m–2) Body fat (%) 32.2 (9.4) Energy 59.6 (19.3–110.1)‡ expenditure (work and recreational activities) MET h week–1
Q2 (1693–2161)
Q3 (2162–2887)
Q4 (2780–6655)
P
1915 (137)
2450 (175)
3556 (730)
0.000
0.26(0.07)
0.29 (0.07)
0.38 (0.12)
0.000
25.9 (5.41)
33.3 (6.8)
46.0 (12.2)
0.000
44 47 (18) 56
53 44 (16) 57
64 40 (15) 56
0.000 0.000 0.058
22 24 28 25
19 23 21 29
17 24 25 28
0.000
27
28
26
0.007
24
25
23
25 20
24 21
23 29
24
18
28
0.017
25
24
36
0.000
25
29
21
26
23
16
27.2 (4.9)
26.4 (4.4)
26.8 (4.6)
0.000
30.3 (8.6) 69.7 (33.6–107.0)
27.8 (8.3) 86.2 (47.1–130.2)
26.6 (8.8) 96.6 (58.8–151.0)
0.000 0.000
*Mean (SD) (all values). Winter: surveyed September to February. ‡ Median (interquartile range) (all such values). P denotes differences across quartiles of total water intake, analysis of variance or Kruskal–Wallis for nonparametric data. Q, quartile, MET, metabolic equivalent tasks. †
552
ª 2013 The British Dietetic Association Ltd.
L. O’Connor et al.
Water intakes in Irish adults
differed significantly with quartile of water intake but no trend in either direction was obvious. Water intake for Irish adults is tabulated by sex and age group in Table 2. Total daily water intake was 2521 mL in men and 2097 mL in women. Total water intake decreased with increasing age group in men (P = 0.000) and did not differ significantly with age group in women (P = 0.143). When adjusted for body weight (kg), there was a higher intake in younger men (18–35 years) than any other age category. No differences were observed between men and women or between different age categories for women. When adjusted for energy intake, women (18–90 years) had higher intakes than men and no differences were observed across age category in either men or women. Sources of water intake are presented in Table 3. Total water intake in Irish males comprised 67% fluids (16% drinking water, 51% other beverages) and 33% food moisture. In women, total water intake comprised 67% fluids (20% drinking water, 47% other beverages) and 33% food moisture. Mean intakes of drinking water decreased with age in both men (P = 0.000) and women (P = 0.001). Within other beverages, the main contributors to water intake in men were alcoholic beverages followed by tea and, in women, the main contributors were tea followed by alcoholic beverages. The proportion of total water intake sourced from food moisture increased with age in women (P = 0.000) but not men. Discussion Total water intakes in the Irish population are similar to the adequate intakes proposed by the EFSA (2010). Intakes were higher in men than in women and were lowest in elderly adults. There was also large variation in intakes within sex- and age-specific groups and, although
likely to be largely a result of individual need variation and response to other stimuli (e.g. temperature and physical activity), the intakes of some participants were low compared to the mean intakes in this population. Because mild dehydration has been associated with various morbidities (Manz, 2007; Armstrong, 2012), this warrants further examination, including in prospective studies. The importance of the source of water intake in the diet is understudied. Various sources of total water intake were shown to differ in their association with dietary characteristics and body weight in a study of US adults (Kant et al., 2009). In the present study, the larger proportion of total water (67%) came from beverage sources and, although drinking water was the single most consumed beverage, the majority of the contribution came from other beverages. Beverages such as milk are a source of important nutrients (Irish Universities Nutrition Alliance, 2011); however, other beverages, such as alcoholic beverages (WHO, 2011) and sugar sweetened beverages (Malik & Hu, 2012; Bray & Popkin, 2013), have been shown to have a detrimental impact on health. Although the effects of increased consumption of certain beverages on health outcomes have been well documented, there has been little research into the effect of substitution of plain water for these other beverages. A systematic review of the impact of water intake on energy intake and weight status examined the data comparing beverage consumption in comparison with drinking water consumption (Daniels & Popkin, 2010). They reported sparse and inconsistent data other than for sugar and artificially sweetened beverages, where sugar sweetened beverages versus water before a single meal equated to a 7.8% higher total energy intake and artificially sweetened beverages had no impact on energy intake among adults. As such, not all beverage sources of water are equal in terms of nutritional and health outcomes. In the present study, the contribution of
Table 2 Total water intakes in adults (n = 1500) by sex and age group: The National Adult Nutrition Survey, Ireland Mean (SD)
Mean (SD)
Mean (SD)
Mean (SD)
Mean (SD)
Age-group
18–90 years
18–35 years
36–50 years
51–64 years
65–90 years
P
Men Total water intake (mL day 1) Total water intake (mL kg 1 day 1) Total water intake (mL kJ day 1)
(n = 740) 2521 (1002)* 30.6 (12.7) 0.26 (0.10)*
(n = 276) 2817a (1128) 35.1a (14.6) 0.26 (0.10)
(n = 205) 2443b (925) 28.7b (10.9) 0.26 (0.10)
(n = 153) 2403b (767) 27.4b (9.5) 0.26 (0.10)
(n = 106) 2071c (870) 26.4b (10.6) 0.26 (0.10)
0.000 0.000 0.408
Women
(n = 760)
(n = 255)
(n = 232)
(n = 153)
(n = 120)
2097 (787) 31.3 (13.2) 0.31 (0.12)
2072 (806) 32.0 (13.1) 0.29 (0.12)
2157 (818) 31.7 (13.6) 0.31 (0.10)
2147 (772) 30.9 (13.4) 0.31 (0.10)
1968 (685) 29.7 (12.5) 0.31 (0.10)
1
Total water intake (mL day ) Total water intake (mL kg 1 day 1) Total water intake (mL kJ day 1)
0.143 0.458 0.139
mL/kg/day, mL per kg of total body weight per day: mL/kcal/day, mL per kcal of total energy intake per day. P & abc denote significant differences across age group within gender, ANOVA. *Denotes significantly different from females (18–90 years) at P < 0.05, independent samples t-test.
ª 2013 The British Dietetic Association Ltd.
553
554
121
Bottled
132
48
Milk
Fruit juices &
746
2
32
(269)*
(24)
(112)
(160)
(87)*
(155)
(388)*
(234)*
(653)
(767)*
(283)*
(581)*
(634)
(946)*
741
3
47
158
62
131
208
92
609
1319
179
578
757
2076
(286)
(23)
(121)a
737
4
30
87
42
(102)a
(180)a
141
446
(173)
193
(284)a
356
(211)a
(808)a
1312
128
(338)a
(904)a
267
395
1706
2443
(703)a
(726)
a
(1072)a
(1128)
(234)
(34)
(126)b
(153)b
(84)b
(167)
(368)b
(272)b
(557)b
(716)a
(312)b
(460)b
(535)
b
(869)b
(925)
755
1
24
50
39
134
606
142
333
1335
68
246
313
1648
2403
Mean
(261)
(7)
(105)b
(119)c
(72)b
(131)
(418)c
(235)c
(498)b
(623)a
(167)b
(491)b
(536)
b
(706)b
(767)
(SD)
765
1
8
22
38
112
587
96
225
1095
29
183
211
1307
2071
Mean c
(298)
(9)
(48)b
(103)d
(60)b
(104)
(368)bc
(182)ac
(416)b
(631)b
(118)c
(360)b
(381)
c
(781)c
(870)
(SD)
(n = 106)
0.684
0.489
0.000
0.000
0.025
0.136
0.000
0.000
0.000
0.007
0.000
0.000
0.000
0.000
0.000
P
637
4
28
74
39
99
476
115
124
976
159
325
483
1460
2097
Mean
(237)
(24)
(124)
(148)
(65)
(121)
(417)
(183)
(230)
(510)
(350)
(465)
(535)
(706)
(787)
(SD)
(n = 760)
560
1
51
146
46
76
307
86
187
923
216
373
589
1512
2072
Mean
(200)a
(7)
(175)a
(202)a
616
5
22
54
35
111
(88)a (72)a
543
146
131
1071
149
320
469
1540
2157
Mean
(215)b
(34)
(111)b
(111)b
(62)ab
(139)b
(496)b
(207)b
(214)a
(610)ac
(332)b
(484)
(517)
b
(754)a
(818)
(SD)
(n = 232)
years
36–50
(283)a
(159)a
(306)a
(463)ab
(425)a
(498)
(607)
a
(734)a
(806)
(SD)
(n = 255)
years
18–35
Superscript lowercase letters denote significant differences across age group within sex (analysis of variance or Kruskal–Wallis test for nonparametric data). *Denotes significantly different from females (18–90 years) at P < 0.05 (Mann–Whitney U-test).
Food moisture
barley cup)
shakes,
protein
chocolate,
drinking
Other (e.g.
drinks
fruit juice
Cordials &
beverages
Carbonated
97
410
smoothies
131
Teas
427
Coffees
beverages
Alcoholic
beverages
Other
1288
366
Tap water
water
487
1775
2817
(SD)
(n = 153)
b
(1002)*
Mean
(n = 205)
b
2521
Drinking water
Fluids
(mL day 1)
intake
Total water
a
Mean
(SD)
Mean
(SD)
(n = 276)
years
(n = 740)
years
65–90 18–90
years
51–64
years
years years
18–35
18–90 36–50
Women
Men
Table 3 Sources of total water intake (mL day 1) in adults (n = 1500) by sex and age group: The National Adult Nutrition Survey, Ireland
739
4
16
35
29
98
586
127
83
986
131
292
423
1409
2147
Mean
(273)c
(19)
(72)b
(86)c
(55)b
(131)ab
(441)b
(198)b
(139)b
(470)a
(272)b
(424)
(478)
a
(647)a
(772)
(SD)
(n = 153)
years
51–64
710
7
5
9
43
123
566
99
26
893
91
274
365
1258
1968
Mean
(234)bc
(28)
(24)b
(36)d
(66)ac
(122)c
(346)b
(155)ab
(55)c
(406)a
(271)c
(394)
(433)c
(572)b
(685)
(SD)
(n = 120)
years
65–90
0.000
0.085
0.000
0.000
0.025
0.000
0.000
0.000
0.000
0.019
0.000
0.213
0.001
0.001
0.285
P
Water intakes in Irish adults L. O’Connor et al.
ª 2013 The British Dietetic Association Ltd.
L. O’Connor et al.
alcoholic beverages to water intakes was high compared to other individual beverages, in particular in young men (those aged 18–35 years). The effects of consuming alcoholic beverages as a source of water may have a negative impact on health additional compared to that from alcohol consumption, and warrant further investigation. Furthermore, in this sample, intakes of tea in men and women and alcoholic beverages in men each contributed almost as much to total water intakes as drinking water did. Because alcoholic beverages and tea are diuretics, the treatment of these sources of total water commensurate with other beverages may not be appropriate. Food moisture is an important source of total water intake in the Irish diet, accounting for 33% of total water intake. The water content of food is one of the major determinants of dietary energy density. Dietary energy density has been positively associated with obesity (Mendoza et al., 2007), diabetes (Wang et al., 2008) and inversely associated with dietary quality (Patterson et al., 2010; O’Connor et al., 2013). Promoting an increased intake of foods with high water content to achieve adequate intakes of water is in keeping with current public health guidelines on reducing the consumption of energy dense foods. This large contribution of food moisture along with the between and within sex and age group variation suggests that assessing fluid intake without considering food intake would provide misleading results. The strengths of the present study include the national representative nature of the data, the detailed food and drink consumption data that were collected at brand level, and the high percentage of intake data that were weighed and not estimated. Also, because intakes were prospectively recorded, recall bias is precluded. This method for calculating water intake also has strengths, including the ability to calculate water in beverages and food moisture, as well as its contribution to water intake in this population; the recording of brand that allows intakes of tap water and bottle water to be distinguished; and the inclusion of questions to determine how milk and water were consumed, therefore correctly identifying whether they should be classified as a food or a beverage. Because water intakes were estimated from selfreported food diaries, estimates may be affected by participant under-, over- and selective-reporting of intakes and portion sizes. However, participants were interviewed and trained in diary completion by qualified nutritionists, diaries were reviewed and suspected gaps in participant’s food records were questioned. A limitation of this method includes the possibility that prompting participants to remember their water intake may have changed their behaviour; however, during training, researchers were made aware of this and trained to be neutral in attitudes towards a participant’s intakes. ª 2013 The British Dietetic Association Ltd.
Water intakes in Irish adults
In summary, we found that mean total water intakes were similar to proposed adequate intakes; some participants had very low water intakes; there was a high contribution of other beverages (in particular alcoholic beverages to total water intakes); and food moisture is an important source of water intake. These detailed estimates can be used as a foundation for further research, a baseline for quantitative recommendations and to guide public health messages regarding adequate water intakes.
Acknowledgments We would like to thank all the participants and staff of the National Adult Nutrition Survey for their time and contribution.
Conflict of interests, source of funding and authorship The authors declare that there are no conflicts of interest. The project was funded by the Irish Department of Agriculture, Food and the Marine and the Health Research Board under their joint Food for Health Research Initiative (2007–2012). L’OC and JW derived the water intakes, carried out the analysis, drafted the initial manuscript and are responsible for the accuracy of the data. AF is a principal investigator of the National Adult Nutrition Survey and provided insight on data analysis and contributed to the manuscript. All authors contributed to critical revisions and have read and approved the final manuscript submitted for publication.
References Armstrong, L.E. (2012) Challenges of linking chronic dehydration and fluid consumption to health outcomes. Nutr. Rev. 70(Suppl. 2), S121–S127. Black, L.J., Ireland, J., Møller, A., Roe, M., Walton, J., Flynn, A., Finglas, P.M. & Kiely, M. (2011) Development of an on-line Irish food composition database for nutrients. J. Food Comp Anal. 24, 1017–1023. Bray, G.A. & Popkin, B.M. (2013) Calorie-sweetened beverages and fructose: what have we learned 10 years later. Pediatr. Obes. 4, 242–248. Chan, W., Brown, J. & Buss, D.H. (1994) Miscellaneous Foods. Fourth Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Chan, W., Brown, J., Church, S.M. & Buss, D.H. (1996a) Meat Products and Dishes. Sixth Supplement to 5th Edition of
555
Water intakes in Irish adults
McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Chan, W., Brown, J., Lee, S. & Buss, D.H. (1996b) Meat, Poultry and Game. Fifth Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Daniels, M.C. & Popkin, B.M. (2010) Impact of water intake on energy intake and weight status: a systematic review. Nutr. Rev. 68, 505–521. Dennis, E.A., Flack, K.D. & Davy, B.M. (2009) Beverage consumption and adult weight management: a review. Eat. Behav. 10, 237–246. European Food Safety Authority. (2010) Scientific opinion on dietary reference values for water. EFSA J. 8, 1459. Food Standards Agency. (2002) McCance and Widdowson’s, The Composition of Foods, 6th edn. Cambridge: Food Standards Agency, Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1988) Cereals and Cereal Products. Third Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1989) Milk Products and Eggs. Fourth Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1991) Vegetables, Herbs and Spices. Fifth Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Unwin, I.D. & Buss, D.H. (1992a) Fruit and Nuts. First Supplement to 5th edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Welch, A.A. & Buss, D.H. (1992b) Vegetable Dishes. Second Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Brown, J. & Buss, D.H. (1993) Fish and Fish products. Third Supplement to 5th Edition of McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry. Holland, B., Welch, A.A., Unwin, I.D., Buss, D.H., Paul, A.A. & Southgate, D.A.T. (1995) McCance & Widdowsons The Composition of Foods, 5th edn. London: Royal Society of Chemistry and Ministry of Agriculture, Fisheries and Food, HMSO. Hu, F.B. & Malik, V.S. (2010) Sugar-sweetened beverages and risk of obesity and type 2 diabetes: epidemiologic evidence. Physiol. Behav. 100, 47–54. Institute of Medicine. (2004) Institute of Medicine. Food and Nutrition Board. Panel on Dietary Reference Intakes for Electrolytes and Water: Dietary Reference Intakes for Water, Potassium, Sodium Chloride, and Sulfate.
556
L. O’Connor et al.
Irish Universities Nutrition Alliance. (2011) National Adult Nutrition Survey Summary Report. Irish Universities Nutrition Alliance. Kant, A.K., Graubard, B.I. & Atchison, E.A. (2009) Intakes of plain water, moisture in foods and beverages, and total water in the adult US population–nutritional, meal pattern, and body weight correlates: National Health and Nutrition Examination Surveys 1999-2006. Am. J. Clin. Nutr. 90, 655–663. Malik, V.S. & Hu, F.B. (2012) Sweeteners and risk of obesity and type 2 diabetes: the role of sugar-sweetened beverages. Curr. Diab. Rep. 12, 195–203. Malik, V.S., Popkin, B.M., Bray, G.A., Despres, J.P., Willett, W.C. & Hu, F.B. (2010) Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis. Diabetes Care 33, 2477–2483. Manz, F. (2007) Hydration and disease. J. Am. Coll. Nutr. 26, 535S–541S. Mendoza, J.A., Drewnowski, A. & Christakis, D.A. (2007) Dietary energy density is associated with obesity and the metabolic syndrome in US adults. Diabetes Care 30, 974–979. O’Connor, L., Walton, J. & Flynn, A. (2013) Dietary energy density and its association with the nutritional quality of the diet of children and teenagers. J. Nutr. Sci. 2, e10. Patterson, E., Warnberg, J., Poortvliet, E., Kearney, J.M. & Sjostrom, M. (2010) Dietary energy density as a marker of dietary quality in Swedish children and adolescents: the European Youth Heart Study. Eur. J. Clin. Nutr. 64, 356–363. Stookey, J.D., Constant, F., Popkin, B.M. & Gardner, C.D. (2008) Drinking water is associated with weight loss in overweight dieting women independent of diet and activity. Obesity (Silver Spring) 16, 2481–2488. Tate, D.F., Turner-Mcgrievy, G., Lyons, E., Stevens, J., Erickson, K., Polzien, K., Diamond, M., Wang, X. & Popkin, B. (2012) Replacing caloric beverages with water or diet beverages for weight loss in adults: main results of the Choose Healthy Options Consciously Everyday (CHOICE) randomized clinical trial. Am. J. Clin. Nutr. 95, 555–563. Vartanian, L.R., Schwartz, M.B. & Brownell, K.D. (2007) Effects of soft drink consumption on nutrition and health: a systematic review and meta-analysis. Am. J. Public Health 97, 667–675. Wang, J., Luben, R., Khaw, K.T., Bingham, S., Wareham, N.J. & Forouhi, N.G. (2008) Dietary energy density predicts the risk of incident type 2 diabetes The European Prospective Investigation of Cancer (EPIC)–Norfolk Study. Diabetes Care 31, 2120–2125. Wareham, N.J., Jakes, R.W., Rennie, K.L., Mitchell, J., Hennings, S. & Day, N.E. (2002) Validity and repeatability of the EPIC0Norfolk Physical Activity Questionnaire. Int. J. Epidemiol. 31, 168–174. World Health Organization. (2011) Global Status Report on Alcohol and Health 2011. Geneva: World Health Organization.
ª 2013 The British Dietetic Association Ltd.
Copyright of Journal of Human Nutrition & Dietetics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
