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Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005)

Chapter: Appendix C: Predictions of Daily Water and Sodium Requirements

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Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

C
Predictions of Daily Water and Sodium Requirements

To generate estimates of water and sodium losses at different energy expenditure levels and thus work rates, the U.S. Army Research Institute of Environmental Medicine (USARIEM) model was adapted for the four levels of energy expenditure identified in the Dietary Reference Intakes report on energy expenditure (IOM, 2002/2005). The USARIEM Heat Strain model is an empirical model that includes an equation to predict sweating rate during work (Moran et al., 1995, Shapiro et al., 1995). This algorithm has been used in the past to prepare military guidance for water needs during training and deployment.

The following is a description of the application of the model:

  • Variables

    • Water requirements (L/d)

    • Sodium requirements (g/d)

  • Prediction ranges

  • Four energy expenditure levels (1,900; 2,400; 2,900; and 3,600 kcal/d)

  • Temperature ranges (15°–40°C)

ANALYSIS

As shown in the example, the environmental, physiological, and individual information was inputted into the model. For any given individual, physiological, or environmental condition, the model predicted expected water losses. These data were then put into an

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

Excel 4.0 spreadsheet and used to generate the dataset of estimated water and sodium requirements at varying energy expenditure levels and temperatures. Environmental and individual assumptions are listed below. These data were then plotted using Sigma Plot 9.0 to generate a graphical display.

ASSUMPTIONS

  • Individual

    • 70-kg person

    • Height = 170 cm

    • Walking velocity = 5 km/h

    • 0% grade

    • Clothing = 1.0 (cotton)

  • Environmental

    • Partly cloudy day

    • Wind speed = 1 m/sec

    • Relative humidity = 50%

    • Outdoor

    • Water vapor pressure = 19.094 mm Hg

    • Load = 0 kg

    • Dry bulb temperature = 30°C

    • Black globe temperature = 45°C

  • Physiological

    • Skin body temperature = 35.0°C

    • Rectal body temperature = 36.5°C

    • Initial heart rate = 60 bpm

    • Rest (N)

    • Exposure I = 720 min (= 12 h)

    • Exposure II = 720 min (= 12 h)

    • Exposure III (min) = 0

    • Exposure IV (min) = 0

  • 1.0 L/d minimal requirements for survival:

  • Sodium concentration of sweat (≈ 35 mmol/L), that of a partially acclimated person

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

Example (not used in this analysis):

The version of the program used was MAT version 9/97. Figures C-1a and C-1b describe the approximate daily water (Figure C-1a) and sodium (Figure C-1b) lost due to sweating as a function of dry bulb temperature and level of physical activity derived from modeling data (Table C-1).

*  

The screen is an example of the input variable capabilities; however, actual data are not presented in the database.

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

FIGURE C-1 Approximate daily water (Figure C-1a) and sodium (Figure C-1b) lost due to sweating as a function of dry bulb temperature and level of physical activity derived from modeling data (Table C-1). The hatched area indicates ≈ 1 L minimal water requirements. The y-axis represents the predicted water requirements that increase because of increased sweat losses to enable thermoregulation. The x-axis is the average daytime dry bulb temperature. The four lines represent the four levels of energy (in kcal/day) used in the model (1,900 kcal; 2,400 kcal; 2,900 kcal; and 3,600 kcal).

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

REFERENCES

IOM (Institute of Medicine). 2002/2005. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press.


Moran D, Shapiro Y, Epstein Y, Burstein R, Stroschein L, Pandolf KB. 1995. Validation and adjustment of the mathematical prediction model for human rectal temperature responses to outdoor environmental conditions. Ergonomics 38:1011–1018.


Shapiro Y, Moran D, Epstein Y, Stroschein L, Pandolf KB. 1995. Validation and adjustment of the mathematical prediction model for human sweat rate responses to outdoor environmental conditions. Ergonomics 38:981–986.

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

TABLE C-1 Generated Database from the USARIEM Prediction Model

Given:

kcal/h

watts

per 12 h (kcal)

Rest

76

88

912

Light

234

273

2,808

Mod

382

444

4,582

Hard

531

618

6,372

Assumption: 1.0 liter water essential (daily resp water loss and kidney loss)

Predicted Sweating Rates (mL/h)

Air Tdb

Rh

Rest

Light

Mod

Hard

10

50

32

100

355

628

15

50

65

204

456

722

20

50

108

339

618

911

25

50

151

473

763

1,069

30

50

201

629

938

1,263

35

50

265

829

1,168

1,524

40

50

361

1,129

1,524

1,934

12 h Air

Scenario

Rest

Light

Mod

Hard

Kcal

Water Loss

10

0.95

0.05

0

0

1,006.8

425

15

0.95

0.05

0

0

1,006.8

867

20

0.95

0.05

0

0

1,006.8

1,440

25

0.95

0.05

0

0

1,006.8

2,009

30

0.95

0.05

0

0

1,006.8

2,672

35

0.95

0.05

0

0

1,006.8

3,522

40

0.95

0.05

0

0

1,006.8

4,796

WBGT

Rest

Light

Mod

Hard

Kcal

Water Loss

9.9

0.7

0.25

0.05

0

1,570

782

14.2

0.7

0.25

0.05

0

1,570

1,434

18.8

0.7

0.25

0.05

0

1,570

2,299

23.1

0.7

0.25

0.05

0

1,570

3,148

27.4

0.7

0.25

0.05

0

1,570

4,141

31.7

0.7

0.25

0.05

0

1,570

5,416

36.2

0.7

0.25

0.05

0

1,570

7,336

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

Hard

A:J13

khard

A:E7

klight

A:E5

kmod

A:E6

krest

A:E4

light

A:H13

mod

A:I13

Rest

A:G13

sr

A:E13.I20

WBGT

A:F13

ttl kcal

ttl water loss

 

1,918.8

1.4

35

23

1,147

1,918.8

2.4

35

23

1,905

1,918.8

2.9

35

23

2,367

1,918.8

3.5

35

23

2,825

1,918.8

4.2

35

23

3,358

1,918.8

5.0

35

23

4,042

1,918.8

6.3

35

23

5,068

ttl kcal

ttl water loss

 

2,481.5

2.3

35

23

1,837

2,481.5

2.9

35

23

2,362

2,481.5

3.8

35

23

3,058

2,481.5

4.6

35

23

3,742

2,481.5

5.6

35

23

4,541

2,481.5

6.9

35

23

5,568

2,481.5

8.8

35

23

7,113

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

WBGT

Rest

Light

Mod

Hard

Kcal

Water Loss

9.9

0.65

0.15

0.15

0.05

2,020

1,445

14.2

0.65

0.15

0.15

0.05

2,020

2,130

18.8

0.65

0.15

0.15

0.05

2,020

3,115

23.1

0.65

0.15

0.15

0.05

2,020

4,047

27.4

0.65

0.15

0.15

0.05

2,020

5,148

31.7

0.65

0.15

0.15

0.05

2,020

6,578

36.2

0.65

0.15

0.15

0.05

2,020

8,754

WBGT

Rest

Light

Mod

Hard

Kcal

Water Loss

9.9

0.45

0.25

0.2

0.1

2,666

2,078

14.2

0.45

0.25

0.2

0.1

2,666

2,925

18.8

0.45

0.25

0.2

0.1

2,666

4,179

23.1

0.45

0.25

0.2

0.1

2,666

5,350

27.4

0.45

0.25

0.2

0.1

2,666

6,741

31.7

0.45

0.25

0.2

0.1

2,666

8,552

36.2

0.45

0.25

0.2

0.1

2,666

11,316

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×

ttl kcal

ttl water loss

 

2,931.9

2.9

35

23

2,371

2,931.9

3.6

35

23

2,922

2,931.9

4.6

35

23

3,715

2,931.9

5.5

35

23

4,465

2,931.9

6.6

35

23

5,352

2,931.9

8.1

35

23

6,503

2,931.9

10.3

35

23

8,254

ttl kcal

ttl water loss

 

3,578

3.6

35

23

2,881

3,578

4.4

35

23

3,562

3,578

5.7

35

23

4,572

3,578

6.9

35

23

5,515

3,578

8.2

35

23

6,634

3,578

10.1

35

23

8,091

3,578

12.8

35

23

10,317

Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 485
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 486
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 487
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 488
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 489
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 490
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 491
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 492
Suggested Citation:"Appendix C: Predictions of Daily Water and Sodium Requirements." Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi: 10.17226/10925.
×
Page 493
Next: Appendix D: U.S. Dietary Intake Data from the Third National Health and Nutrition Examination Survey, 1988–1994 »
Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate Get This Book
×

Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate The Dietary Reference Intakes (DRIs) are quantitative estimates of nutrient intakes to be used for planning and assessing diets for healthy people. This new report, the sixth in a series of reports presenting dietary reference values for the intakes of nutrients by Americans and Canadians, establishes nutrient recommendations on water, potassium, and salt for health maintenance and the reduction of chronic disease risk. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate discusses in detail the role of water, potassium, salt, chloride, and sulfate in human physiology and health. The major findings in this book include the establishment of Adequate Intakes for total water (drinking water, beverages, and food), potassium, sodium, and chloride and the establishment of Tolerable Upper Intake levels for sodium and chloride. The book makes research recommendations for information needed to advance the understanding of human requirements for water and electrolytes, as well as adverse effects associated with the intake of excessive amounts of water, sodium, chloride, potassium, and sulfate. This book will be an invaluable reference for nutritionists, nutrition researchers, and food manufacturers.

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