1. Nutrients – Nutrition

2. Nutrients
To understand how food affects health & development, it is important to look at:
Nutrients
How they work (function)
Foods they are found in (sources)
Are the chemical compounds in food, and they are required by living things to maintain life

3. Nutrients
The best way to maintain a balanced diet is to eat a wide variety of foods. There are 6 categories of nutrients that are needed for optimal health and individual human development.
They are:
Carbohydrates
Protein
Fats
Vitamins
Minerals
water

4. Macro & micro Macronutrients: required by the body in LARGE amounts
Macro = big
Micronutrients: required by the body in SMALL amounts
Micro = small
Regardless of the quantity needed by the body, each nutrient has a different role to play and all re important for health and development.

5. Macro & micro Macronutrients Micronutrients Carbohydrates Calcium
Protein
Iron
Lipids
Vitamin A
Water
Vitamin D
Vitamin C
B-group vitamins

6. Carbohydrates ~ CHO
The main function of carbohydrates is to provide fuel for energy
Glucose is the preferred fuel for energy in the human body and CHO are rich in glucose, and as a result should provide the majority of an individuals energy needs.

7. CHO Carbohydrates ~ CHO Glucose molecules
Absorbs into the blood stream
CHO
Glucose molecules
1g CHO = 16KJ of energy

8. Glycemic Index (GI)
GI ranks carbohydrate foods according to the effect they have, when eaten, on blood glucose levels
Low GI
Broken down slowly by the body resulting in gradual rise in blood glucose levels (slow, sustained energy release)
High GI
Broken down quickly by the body and result in rapid increase in blood glucose levels (quick burst of energy but also quickly disappears)

9. Carbohydrates ~ CHO
Glucose that is not used is stored in the body as adipose tissue.
Most CHO are found in foods of plant origin.
Eg. Potatoes, rice, pasta, breakfast cereals

10. Learning task
Complete case study on page 82 of the textbook.

11. Protein
Protein is made up of smaller building blocks called amino acids.
There are 20 different types of amino acids that humans need to function properly.
Classified as either essential or non-essential amino acids depending on composition of amino acids.

12. Complete Proteins Incomplete Proteins
Some food sources are termed ‘ complete proteins.
Complete Protein
Made up of essential amino acids (AA’s you can only get from food sources)
Incomplete Protein
Made up of non-essential amino acids (AA’s your body can produce by itself)
Complete Proteins
Incomplete Proteins
FOOD SOURCES
Meat, chicken, cheese, eggs, milk
Rice, legumes, nuts, vegetables
Foods of plant origin
Foods of animal origin

13. Protein Protein has two main functions in the body;
To build, maintain and repair body cells
Acts as a fuel for producing energy

14. Fat (often referred to as lipids)
Fats are often associated with negative effects on the body, they are required for adequate health and development throughout the lifespan.
Main function
Provide energy ~ 1g fat = 37kj of energy
Provide insulation
Maintenance of cell membranes (structure of the cells to assist with transporting nutrients, gases and waste)

15. Fats
Based on their chemical make-up, fats can be classified into four broad categories;
Monounsaturated
Polyunsaturated
Saturated
Trans Fats

16. Mono and poly unsaturated Often considered the good fats
Are associated with reduced risk of heart disease
Monounsaturated fats are liquid at room temp and begin to solidify if placed in the fridge.
Polyunsaturated fats are generally liquid at room temp and when placed in the fridge.
Two types of polyunsaturated fats , omega 3 and omega 6.
Saturated and trans fats
- Known as ‘ bad fats’ because they increase cholesterol levels in the blood
Saturated fats are generally found in foods of animal origin and are often solid at room temperature.
Trans fats are found naturally in certain foods, most trans fats are created when liquid oil is converted into solid fat. For this reason, they are generally found in processed foods eg. Pies
Monounsaturated
Polyunsaturated
Saturated
Trans fats
Olives
Olive oil
Avocado
Nuts
Some margarines
Vegetable oils
Oily fish (salmon, tuna, sardines
Meat
Butter
Cream
Coconut cream
Hydrogenated vegetable fats
Fried take away
Pastries

17. Fibre
Fibre is a type of CHO that is required for optimal health and individual human development of youth.
Fibre does not get absorbed by the body. Rather, it travels through the digestive system, acting like a cleaner as it moves.

18. Fibre Function Essential for maintaining a healthy digestive system
Regulates bowels
Increases feelings of fullness after meals
Reduces the amount of cholesterol that is absorbed by the body, which reduces the risk of Cardiovascular disease later in life
Slows down glucose release rate.

19. Fibre
Sources
Legumes, bread (wholemeal), cereals (bran) , fruits, vegetables, nuts & seeds
As fibre absorbs water, increased fibre intake should be accompanied by increased water consumption.

20. Test your knowledge
Page 97
Questions 1, 7, 8