Nutrition | Year 8 Biology (Cambridge) PDF Download

Introduction to Nutrition

• Nutrition is the process by which organisms obtain and utilize food for growth, maintenance, and repair.
• It involves consuming a balanced diet that provides essential nutrients.

Nutrients and Their Functions

• Carbohydrates:
  • Primary source of energy for the body.
  • Examples include bread, rice, and pasta.
• Proteins:
  • Essential for growth, repair, and maintenance of body tissues.
  • Found in foods like meat, fish, beans, and nuts.
• Fats:
  • Provide energy and support cell growth.
  • Sources include oils, butter, and avocados.
• Vitamins:
  • Essential for various metabolic processes.
  • Examples include Vitamin C (found in citrus fruits) and Vitamin D (synthesized by the body in sunlight).
• Minerals:
  • Important for bone health, nerve function, and fluid balance.
  • Examples include calcium (found in dairy products) and iron (found in red meat and leafy greens).

Impact of Nutrition on Health

• Healthy Eating Habits:
  • Eating a variety of foods ensures intake of all necessary nutrients.
  • Example: Balanced meals include proteins, carbohydrates, and fats.
• Role of Dietary Fiber:
  • Improves digestion by adding bulk to stool.
  • Examples include whole grains, fruits, and vegetables.

Physical Activity and Health

• Benefits of Regular Exercise:
  • Improves cardiovascular health by increasing blood circulation.
  • Example: Activities like running, swimming, or cycling.
• Impact of Sedentary Lifestyle:
  • Increases risk of obesity and related health issues.
  • Example: Spending long hours sitting without physical activity.

Factors Affecting Respiratory and Cardiovascular Health

• Smoking and Lung Function:
  • Damages lungs and reduces lung capacity.
  • Example: Long-term smokers often experience shortness of breath.
• Salt Intake and Blood Pressure:
  • High salt intake can lead to hypertension.
  • Example: Consuming salty snacks regularly increases blood pressure.

Conclusion

Understanding nutrition and maintaining a balanced diet alongside regular physical activity is crucial for overall health and well-being. It helps in preventing various diseases and promoting a healthy lifestyle. Learning about these factors from a young age sets the foundation for a lifetime of good health habits.