1. Human nutrition and digestion
The components of a balanced diet

2. Learning outcomes 1.1 Describe the components of a balanced diet
1.2 Explain the role of each component of a balanced diet in the functioning of the body
1.3 Explain the symptoms of deficiency of some vital nutrients

3. Have a look at the menus on the hand out
Which do you think are healthy and why?
Then answer the questions.

5. A balanced diet
A balanced diet provides an adequate intake of energy and nutrients needed for the maintenance of the body for good health.
Our diet should provide the body with molecules for growth, repair, movement and the functioning of vital organs

6. Macronutrients What are the three macronutrients?
What are their subunits called?
What are the bonds called that hold their subunits together?
It’s back to biochemistry!!

7. Micronutrients Nutrients required in the diet in very small quantities
E.g. fat soluble vitamins
Water soluble vitamins
minerals

8. Cells can convert some compounds into others e. g
Cells can convert some compounds into others e.g. glucose can be converted to fat for storage, proteins are made from amino acids and phospholipids are made from fatty acids and glycerol
1. What are the molecules called that can catalyse the reactions that create the macromolecules?

9. Essential nutrients
Essential nutrients are compounds that cells cannot make from anything else
These compounds have to be provided for in the diet
Can you name some?
Essential amino acids
Essential fatty acids
Most vitamins

10. Essential fatty acids
Omega-3 - derived from linolenic acid and found in flaxseed oil, rapeseed oil, soya beans, walnuts, cod liver oil, herring, sardines and mackerel. The body needs about 2g a day.
Omega-6 - derived from linoleic and archidonic acids and sourced from olive, sunflower, corn, evening primrose and starflower (borage) oils. The body needs 4g a day.
Hemp Seed oil is the only edible seed oil that contains a perfect blend of the essential Omega-3 and Omega-6 fatty acids, and GLA (gamma linolenic acid).

11. Water
The diet must provide enough water to replace what is lost each day
Cell mass is between 70 and 95% water
Water is a transport medium in the body e.g. blood and lymph
Chemicals can dissolve in water allowing them to move freely and react with other chemicals e.g. chemical reactions in cells

12. Fibre
Dietary fibre cannot be digested by the digestive enzymes in the gut
Its role is to aid the movement of the food along the gut
Now have a go at the work sheet on ‘Types of Food’

13. Have a go at the work sheet
‘Types of food’

14. Deficiencies
What are the deficiencies of the following called?
Iron
Vitamin C
Vitamin D
Calcium
Vitamin A
Iodine
Choose a deficiency and describe & explain the symptoms. Work in pairs. Information to be placed on the white board or ppt

22. Minerals Iron Calcium Iodine Potassium Sodium
Haemoglobin, oxygen transport hormone synthesis
Muscle contraction, blood clotting and bone meralisation
Production of thyroxin and tri-iodothyronine regulation of metabolism
Muscle contraction, and transmission of nerve impulses

23. Vitamin A -