Meaning, Importance and Functions of Nutrition

• Nutrition

  The science of food and nutrients, their action and interaction, in relation to providing the body with the necessary substances to maintain homeostasis
• Nutritional balance

  • Impacts the health maintenance and disease prevention
  • Essential for growth and optimal bodily function
• Process for nutrients use by the body

  1. Ingestion

  2. Absorption

  3. Digestion

  4. Energy production

  5. Excretion
• Food functions

  Provide energy sources<|>Build tissues<|>Regulate metabolic processes
• Food makes your body work, grow and repair itself
• The kind of food you eat can affect the efficiency of these processes
• Food composition

  • Macro-nutrients
  • Micro-nutrients
  • Water
  • Roughage (dietary fiber)
• Macro-nutrients

  Major nutritional components that are present in relatively large amounts, such as proteins
• Micro-nutrients

  Major nutritional components that are present in relatively small amounts, such as vitamins
• Cells

  Composed of water, inorganic ions, and carbon-containing (organic) molecules
• Water is the most abundant molecule in cells, accounting for 70% or more of total cell mass
• The interactions between water and the other constituents of cells are of central importance in biological chemistry
• Sources of energy and nutrients needed by the body

  • Air you breathe
  • Food you eat
  • Fluids you drink
• Components of a balanced diet

  • Fruit and vegetables
  • Meat, fish, egg and beans
  • Rice, bread, pasta and other starchy foods
  • Milk and dairy foods
  • Fatty and sugary foods
• Fruit and vegetables

  • Great source of fibre and a variety of vitamins and minerals
  • Generally low in fat
• Meat, fish, egg and beans

  • Great source of protein, iron and zinc
  • Choose lean cuts of meat to reduce fat intake
• Rice, bread, pasta and other starchy foods

  • High in carbohydrates
  • Wholegrain varieties are a great source of fibre and protein
• Milk and dairy foods

  • Can be high in fat
  • Great source of calcium and protein
• Fatty and sugary foods


  • High in fat and sugar
• Nutrients in foods

  • Fats
  • Carbohydrates
  • Protein
  • Vitamins and minerals
• Fats

  Saturated and trans fats increase your risk of health problems<|>The right fats can help lower cholesterol and fight fatigue
• Carbohydrates

  Complex carbs help protect against health problems<|>Simple carbs digest quickly and cause spikes in blood sugar levels
• Protein

  Used by the body for growth and maintenance
• Be careful! Many fat-free foods are high in calories and can result in weight gain
• For a healthier diet, replace refined (white) bread, pasta and rice with wholegrain varieties
• Cell composition

  • 70-90% water
  • Organic chemistry key to construction of cells
  • Monomers: sugars, fatty acids, nucleotides, amino acids
• Macromolecules

  • Polysaccharides
  • Lipids
  • Nucleic acids
  • Proteins