#sreeshanbiology #textbook #igcse

Ch:- 7

Pg:- 107,108,109,110,111,112,113

1. Diet

Diet refers to the food and drink consumed by an individual regularly. It provides the energy and nutrients required for the body to function properly.

2. Need for Food

• Energy: Food provides energy for physical activities and metabolic processes.

• Growth and Repair: Nutrients help in building new tissues and repairing damaged ones.

• Body Functions: Food supports processes like digestion, respiration, and maintaining immunity.

• Survival: Food is essential to sustain life.

3. Balanced Diet

A balanced diet contains all the nutrients in appropriate amounts to meet the body's requirements. It includes:

• Macronutrients: Carbohydrates, proteins, and fats for energy and growth.

• Micronutrients: Vitamins and minerals for proper body functions.

• Fiber: For healthy digestion.

• Water: For hydration and metabolic processes.

Importance of a Balanced Diet:

• Prevents deficiencies and diseases.

• Supports growth and development.

• Enhances physical and mental well-being.

Classes of food:

1. Carbohydrates

• Function: Provide energy.

• Sources: Rice, bread, potatoes, fruits, and sugar.

2. Proteins

• Function: Build and repair tissues; essential for growth.

• Sources: Meat, fish, eggs, beans, and dairy products.

3. Fats

• Function: Provide concentrated energy and help in absorption of fat-soluble vitamins.

• Sources: Butter, oils, nuts, and fatty fish.

4. Vitamins

• Function: Regulate body processes and prevent diseases.

• Examples:

  • Vitamin A (for vision),

  • Vitamin C (immunity),

  • Vitamin D (bone health).

• Sources: Fruits, vegetables, eggs, and sunlight (Vitamin D).

5. Minerals

• Function: Build strong bones, teeth, and support vital functions.

• Examples:

  • Calcium (bones),

  • Iron (blood),

  • Potassium (muscle function).

• Sources: Milk, leafy vegetables, meat, and nuts.

6. Fiber

• Function: Aids digestion and prevents constipation.

• Sources: Whole grains, fruits, vegetables, and legumes.

7. Water

• Function: Maintains hydration, aids digestion, and regulates temperature.

• Sources: Water, fruits, and vegetables.