Nutrition

Question 1

Explain why obesity is an issue in Australia and briefly how it happens?

Answer 1

More people relying upon prepared food
Lack of nutritional diversity (not all veggies have the same nutrients)
Hidden calories
E.g. ‘no fat’ yoghurt vs regular = same calories!
If <50 g/day, proteins and fats used for energy
American diet ~ 46% carbohydrates
Rice, pasta, breads inexpensive  higher percentage in low-income groups
Highly refined carbohydrates (sugary foods) 
Nutritional deficiencies; obesity

Question 1

Identify the different nutrients our body requires to function?

Answer 1

Carbohydrates (simple & complex)
Lipids (triglycerides & cholesterol)
Proteins
Vitamins
Minerals
Water

Question 2

Carbohydrates
Approx. daily requirements?
General sources?
Uses in the body?

Answer 2

Need 130g/day 45-65% of
total nutrients
- Starch (complex) in grains and vegetables
- Sugars (simple) in fruits, sugarcane, sugar beets, honey and milk/dairy
- Insoluble fibre - cellulose in vegetables; not digested
- Soluble fibre - pectin in apples and citrus fruits; reduces blood cholesterol levels
- Glucose - fuel used by cells to make ATP
- Some cells use fats for energy
- Neurons and RBCs rely entirely on glucose
- Neurons die quickly without glucose
- Excess glucose converted to glycogen or fat and stored

Question 3

Lipids
What types of lipids, good vs bad?
General sources?
Uses in the body?

Answer 3

Triglycerides (neutral fats)
Saturated fats in meat, dairy foods, and tropical oils; hydrogenated oils (trans fats)
Unsaturated fats in seeds, nuts, olive oil, and most vegetable oils
Essential fatty acids
Linoleic and linolenic acid, found in most vegetable oils
Uses in body:
Phospholipids essential in myelin sheaths and all cell membranes
Adipose tissue  protection, insulation, fuel storage
Prostaglandins  smooth muscle contraction, BP control, inflammation
Help absorb fat-soluble vitamins (e.g. the antioxidants A,E and D)
Cholesterol in egg yolk, meats, organ meats, shellfish, and milk products
Liver makes ~85% cholesterol despite intake
Cholesterol stabilizes membranes; precursor of bile salts, steroid hormones

Question 4

Proteins
Approx. daily requirements?
General sources?
Uses in the body?

Answer 4

0.8g per kg, approx 56g per 70g
Dietary sources
Eggs, milk, fish, most meats, soybeans contain complete proteins
Contain all needed amino acids
Legumes, nuts, and cereals contain incomplete proteins (lack some essential amino acids – usually lysine and isoleucine)
Legumes and cereal grains together contain all essential amino acids
Varied diets cover all amino acids
Uses in the body:
Structural materials
Keratin (skin); collagen and elastin (connective tissue); muscle proteins
Functional molecules
Enzymes, some hormones
Amino acids can be burned for energy

Question 5

What are the key water and fat soluble vitamins and how do we use them?

Answer 5

Water
- B complex vitamins
- Vitamin C
Fat soluble
A, D, E, K

Question 6

What are some of the key minerals we require?

Answer 6

Calcium
Iron
Phosphorus
Iodine
Potassium
Sodium and chloride