Water | Food & Nutrition for Year 6 PDF Download

Introduction

• Water's Classification: Not technically a nutrient as it provides no nutrition, but vital for numerous bodily functions.
• Water Intake: Enters the body through consumed fluids and various foods.
• Hydration Role: Increases body hydration, essential for health.
• Regulation Need: Must be carefully balanced to maintain health.
• Water Loss: Exits through sweat, exhalation, and urine produced by kidneys.
• Kidney Function: Regulates blood water levels by adjusting urine output—more when water is excessive, less when scarce.

Functions of Water

• Waste Elimination: During urine production, the kidneys filter waste from the blood, including urea, a toxic byproduct of protein breakdown, which is then excreted.
• Digestive Health: Water helps prevent constipation by aiding in the movement of digested food through the intestines.
• Temperature Regulation: Water’s high heat capacity allows it to absorb significant energy when it evaporates. When body temperature rises, sweat glands release liquid sweat onto the skin, which absorbs heat from underlying blood vessels, converting to a gas and cooling the body.
• Digestion: In the mouth, water in saliva softens food into a paste for easier passage through the digestive system. In the stomach, water dilutes acid, assisting in moving digested food through the small intestine and forming feces.
• Transport: Water is a primary component of bodily fluids, such as blood, tissue fluid surrounding cells, and cytoplasm within cells. These fluids dissolve and transport essential substances and waste products throughout the body.

Consuming the Correct Amount of Water

The amount of water needed daily varies based on factors like:

• Age
• Gender
• Diet
• Physical activity levels
• Climate

In the UK, the NHS advises consuming 1.2–1.8 liters of water daily, roughly 6–8 glasses. While all fluids contribute to hydration, water is the most effective. Drinks like coffee and alcohol are less efficient at hydrating.

Approximately 20–30% of daily hydration comes from food, with 70–80% from beverages.

Risks of Improper Water Intake

• Dehydration: Insufficient water intake can cause headaches, fatigue, and dizziness.
• Water Intoxication: Excessive water consumption, though rare, can lead to cell swelling, including in the brain, potentially causing seizures and permanent damage. This typically occurs in extreme cases, such as water-drinking contests, endurance sports, or intense military training.

Drinking water in hot climates