1. Core Topic 1: Fundamentals of Human Nutrition

2. Overview of Topic 1
1.1 Humans need essential nutrients for good health:
Investigate why humans must include essential nutrients in their diet.
Analyse how macronutrients and micronutrients function and their relationship to optimal wellbeing.
Investigate the relevance of Acceptable Macronutrient Distribution Ranges (AMDR) and develop skills to compare percentage requirements.
Understand and investigate how foods can be combined to improve their nutritional status.

3. Macronutrients - Carbohydrates
Found in plants and created through the process of photosynthesis.
When plants use energy from the sun to combine CO2 and water from the environment to form carbohydrate.
Carbohydrates are made up of Carbon, Hydrogen and Oxygen; thus, carbohydrates are abbreviated as CHO.

4. Why do we need Carbohydrates?
The body requires carbohydrates to:
Provide the body with heat and fuel to perform daily activities (1g = 16kj)
Provide dietary fibre to stimulate the digestive system
The regulation of protein and fat use by the body

5. Carbohydrate Classification
Carbohydrates
Monosaccharide
Disaccharide
Polysaccharide
The term ‘saccharide’ refers to sugar. Therefore, the classification of each carbohydrates depends on the total amount of sugar units.

6. Monosaccharide Simple sugars There are three forms of monosaccharides:
Glucose
Most carbohydrates are converted to glucose by the digestive system
Easily absorbed and used for energy
The body’s preferred source of fuel
Sources include ripe fruits, some vegetables and honey
Fructose (fruit sugar)
sources include fruit and honey
Galactose
formed during the digestion of lactose (milk sugar)

7. Disaccharide Disaccharides contain two monosaccharide units.
Disaccharides include:
Sucrose (glucose + fructose)
Found in cane sugar, fruits and some vegetables
Lactose (glucose + galactose)
Found in dairy products
Maltose (2 molecules of glucose)
Found in germinating grain crops

8. Investigation Skills Name the graph. Interpret the findings
The sugar content of various foods.
Name the graph.
Interpret the findings

9. Polysaccharide
Monosaccharides can be joined together in long chains called polysaccharides.
Polysaccharides include:
Starch
Found in cereals including wheat, rice and corn, cereal products including rice and pasta and vegetables including potato and peas.
Glycogen
Stored in the liver and muscles
Can be converted back to glucose

10. Polysaccharides Pectin (soluble)
Found in seeds, pith and peel of fruits and vegetables.
Digested by intestinal bacteria.
Attracts water and turns to gel during digestion
May help reduce cholesterol
Allows nutrients to be released more slowly
Contributes to a feeling of satiety

11. Polysaccharides Cellulose (dietary fibre – insoluble)
Forms in the cell walls of plants
Partly digested
Adds bulk to the stool
Appears to help foods pass quickly through the stomach and intestines
Contributes to a feeling of satiety

12. How much Carbohydrate? 1g of carbohydrate yields 16kj of energy.
45-65% of the total daily energy intake should be from Carbohydrates.
For example if the total energy intake is 8,000kj, then 3,600-5,200kj should derive from carbohydrates.

13. Carbohydrate Deficiency and Excess
Symptoms of deficiency
Symptoms of excess
Fatigue
Inability to exercise (no glycogen)
Headaches
Fainting
Lack of vitamins and minerals
Low dietary fibre intake – constipation
Protein depletion
Dental caries (decay or cavity) build up of plaque, which sticks to acids in our mouth. The acid eats away at the outermost layer of the tooth called the enamel.
Weight gain – increase in adipose tissue
The brain and energy system can only use glucose for energy. Without glucose headaches, fainting and inability to exercise may result.
Excess glucose is converted to glycogen, which is stored in the liver and muscles. Any glycogen remaining is placed in adipose tissue (body fat) Glycogen is necessary for exercise.
When insufficient carbohydrate and lipids are consumed, the body converts protein into glucose.
A carbohydrate deficiency will deplete protein stores. The body will convert muscle tissue into glucose to provide energy.

14. Dietary Fibre Fibre is grouped into two types:
Indigestible
Insoluble
Digestible
Soluble
Fibre is grouped into two types:
Soluble – digested by intestinal bacteria
legumes, oats, barley and fruits
Insoluble –partly digested
Vegetables, grains, cereals and seeds

15. Why is Fibre Important? Fibre is important in the diet because it:
Slows down initial digestion for nutrients to be released into the body slowly; thus, the absorption of vitamins and minerals is maximised.
Helps produce soft, bulky stools, which are easy to expel from body.
Provides a feeling of fullness in the stomach – thus reduces obesity.
Increases the transit time of stools through intestines; thus, prevents constipation, diverticular disease, bowel cancer, haemorrhoids and potentially varicose veins.
Slow digestion important for diabetics, as it helps regulate blood sugar levels.

16. What is the graph depicting?
Depicting the fibre content of different foods.
Name the graph.
Interpret the results.

17. Why is Fibre Important? Fibre is important in the diet because it:
Slows down initial digestion for nutrients to be released into the body slowly; thus, the absorption of vitamins and minerals is maximised.
Helps produce soft, bulky stools, which are easy to expel from body.
Provides a feeling of fullness in the stomach – thus reduces obesity.
Increases the transit time of stools through intestines; thus, prevents constipation, diverticular disease, bowel cancer, haemorrhoids and potentially varicose veins.
Slow digestion important for diabetics, as it helps regulate blood sugar levels.

18. The Glycaemic Index (GI)
‘The speed at which a carbohydrate food breaks down into glucose has been studied and the foods have been ranked.’ (Queensland Government 2011)
The amount and type of sugar in a food will impact a food’s GI.

19. Glycaemic Index (GI) Milk Weet Bix French fries
Low = < 55% Intermediate = 55-69% High > 70%
Milk Weet Bix French fries
Yoghurt Brown Rice White bread
Nuts Soft drinks Jelly Beans
Beans Brown rice Water melon
Pasta Sucrose Rice crackers

20. Glycaemic index (GI) Low GI diets:
help diabetics control glucose tolerance
can reduce total cholesterol and triglyceride levels, increase HDL, reduce blood clotting and risk of CVD
are more filling and can aid wait control

21. Structure of a Extended Response Question
Usually written in three of four parts. Ensure you address each dot point.
This section must be written in continuous prose. NO DOT POINTS !
Definitions should be given where possible.
Give yourself time to structure your response.
Use relevant explanations and examples to support your response.

22. Extended Response Question
Polysaccharides are better for us than monosaccharides and disaccharides.
Define monosaccharides, disaccharides and polysaccharides.
Discuss the significance of polysaccharides for human beings.
Outline concerns if a person does not consume sufficient Polysaccharides.
Outline dietary strategies to boost one’s intake of polysaccharides.