## Water

Approximately 60% of total body weight is water. Thus, adequate amounts of water must be consumed daily to ensure the normal functioning of the body and to replenish lost fluids. Water is needed to help digest and absorb nutrients, excrete wastes, maintain blood circulation, and maintain body temperature.

Worksheet 2-4. Calculate Your Daily Water

Requirement

0.5 x_(body weight) ^ 8 oz. per cup = _cups per day.

Note: Exercise, heat, cold, and altitude can increase fluid requirements. See Chapters 11 and 12.

### Maintaining Fluid Balance

Fluid balance, like energy balance, is determined by the ratio of fluid losses to fluid intakes. With dehydration, water loss exceeds intake and fluid balance becomes negative. Water is lost in the urine, in stools, in sweat, and through breathing. When activity levels are low, most fluids are lost through the urine. When activity levels are high or the temperature is high, most of the fluid is lost through sweat. To maintain fluid balance you must consume enough fluids each day.

Dehydration

Dehydration results when fluid losses exceed fluid intake. Conditions that can lead to dehydration include:

♦ Not drinking enough fluids daily.

♦ Working or exercising in a hot environment (wet or dry).

♦ Working or exercising in a cold environment (wet or dry).

♦ Going to high altitudes.

♦ Drinking too much alcohol or exercising with a hangover.

If 4% of your body weight is lost through fluid losses, decision-making, concentration, and physical work are impaired. A loss of 20% of body water can result in death (see Figure 2-1).

Figure 2-1. Symptoms of Dehydration

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Figure 2-1. Symptoms of Dehydration

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Worksheet 2-5. Calculate Your Water Loss Limit -->

A 2% loss in body weight due to fluid loss equals: _x 0.98 =_

lbs.

Goal: Rehydrate to stay above this weight!

Chapter 3 outlines the dietary guidelines which apply the information discussed throughout this chapter to everyday dietary practices and food choices.

Eating for Optimal

Health and Fitness

In this chapter you will learn about:

♦ Dietary Guidelines.

♦ The Food Guide Pyramid.

♦ Nutrient-dense foods.

♦ Vegetarian diets.

You have heard the saying "You are what you eat". That is because what you eat makes a difference in how you perform, how you feel, and affects your long-term health. This chapter provides information on how to follow healthy dietary practices whether you are eating at home, in a galley, or at a restaurant.