SAC 1

Question 1

What is the difference between hunger and appetite?

Answer 1

Hunger is the uncomfortable feeling associated with a lack of food. Hunger pains are caused by an empty stomach contracting and is a physical response that cannot be ignored. Appetite is the desire for food, even when the body is not hungry.

Question 2

Physiology of appetite

Answer 2

Appetite is triggered by sight, smell or even talking about food. These senses send messages to the brain that food is available to eat. In response to these messages, the body produces saliva, produces a tingling sensation in the pit of our stomach, contracting the stomach and producing digestive chemicals in the intestines. Ghrelin, the appetite-enhancing hormone, is also released, mainly by the stomach. Stomach ‘growling’ occurs because the stomach is producing ghrelin.

Question 3

Conditioning of appetite

Answer 3

If an image of a chocolate chip cookie makes you salivate, you have learned that when you see a food like this, you usually get to eat it. This is called conditioning. The mouth salivating is a PHYSIOLOGICAL response to appetite and the learned behaviour is a CONDITIONED response.

Question 4

What is satiety?

Answer 4

Feeling a sense of fullness in the absence of hunger is called satiety. As blood glucose levels increase, the pancreas and liver send signals to the brain to stop eating. Fat cells release leptin, known as the ‘satiety hormone’ when someone is satiated. This process can take around 20 minutes. The main role of leptin is to suppress appetite and hunger and control energy intake.

Question 5

Foods that provide satiety

Answer 5

Foods high in protein as protein, low GI foods, foods high in fiber and unprocessed foods

Question 6

Why are foods high in protein high in satiety?

Answer 6

Protein is the most filling macronutrient as it may reduce ghrelin, same kilojoules per gram compared to carbs but stay longer in the stomach than carbs which may contribute to feelings of fullness

Question 7

Why are low GI foods high in satiety?

Answer 7

Carbs with a low GI value (55 or lower) make you feel full for longer because they are more slowly digested, absorbed and metabolized. Cause a lower and slower rise in blood glucose and insulin levels

Question 8

Why are foods high in fibre good for satiety?

Answer 8

Fibre provides bulk and helps you feel full for longer and slow down the emptying of the stomach and increases digestion time.

Question 9

Why are unprocessed foods good for satiety?

Answer 9

Unprocessed or slightly processed foods are generally more filling than high processed foods.

Question 10

Foods that do not provide satiety

Answer 10

Foods high in sugar, drinks high in sugar, highly processed foods. This is because they often contain high levels of sugars and fats. Fats provide less satiety than carbs and protein and sugar only stimulate satiety in the short-term.

Question 11

Sensory appreciation of food

Answer 11

Studies show how our sensory appreciation of food (how much we like the sensory properties of food) influences our appetite and satiety.

Question 12

Enzymatic hydrolosis

Answer 12

The term used to describe the process where enzymes use water to break down bonds during digestion

Question 13

Peristalsis

Answer 13

The term used to describe the wave-like involuntary muscle contractions that move food along the digestive system

Question 14

What do the macronutrients convert to during digestion?

Answer 14

Carbohydrates into glucose
Proteins into amino acids
Fats into fatty acids and glycerol

Question 15

Order of digestion (including accessory organs)

Answer 15

Mouth (tongue, salivary glands) → oesophagus → stomach → small intestine (liver, gallbladder, pancreas) → large intestine → rectum and anus

Question 16

Digestion of carbohydrates

Answer 16

Salivary glands release the enzyme ‘salivary amylase’ that breaks down starch molecules into simpler sugar units.
Gastric juices in the stomach are too acidic and inactivate the amylase
In the small intestine, the pancreas releases pancreatic juices, containing pancreatic amylase.

Question 17

Absorption of carbohydrates

Answer 17

Villi line the walls of the small intestine where they absorb the monosaccharides that travel to the liver via bloodstream where they are converted into glucose. The liver releases glucose into the bloodstream if energy is required immediately and if it is not needed immediately, it is converted into glycogen. The liver cannot store large amounts of glycogen so excess is converted into fat and stored around the body.

Question 18

Utilization of carbohydrates

Answer 18

Carbohydrates are the body’s preferred energy source, sugars and starches are carbohydrates

Question 19

Functions of fibre

Answer 19

Often considered a carbohydrate but is technically not. Functions of fibre include keeping our digestive systems healthy, stabilizing blood glucose and cholesterol levels, preventing constipation and prevents some diseases including bowel cancer, coronary heart disease and type 2 diabetes.

Question 20

Digestion of fats

Answer 20

Salivary glands release lingual lipase that blends with fat making it easier to swallow, not really assisting in breaking down the fats in the mouth. The bolus then enters the stomach where gastric lipase converts fat in fatty acids and glycerol in about 2-4 hours. It then enters the small intestine as chyme where the gallbladder releases bile made by the liver that helps break down the fat into smaller droplets. The pancreas also releases pancreatic juices containing pancreatic lipase, breaking down the fat into fatty acids and glycerol.

Question 21

Absorption of fats

Answer 21

Fat droplets are too large to enter the villi so they enter the lacteal instead that connects to the lymphatic system. The lymphatic system then transports the fats via bloodstream to the liver and tissues such as fat and muscle where they are stored or used by cells.

Question 22

Utilization of fats

Answer 22

Fats provide energy, absorb certain nutrients and maintains the core body temperature. Good fats are also important for brain development in unborn babies, infants, children and adolescents.

Question 23

What is cholesterol?

Answer 23

A term often associated with fat. It is a fatty substance that the body needs for processes such as making hormones and building cells. Many people obtain cholesterol they need from foods they consume but the body is also capable of making it.

Question 24

Types of fats

Answer 24

Saturated fats are often referred to as unhealthy fats and eating a large amount is linked with increased risk of heart disease and high blood cholesterol levels. Monounsaturated fats lower the level of bad cholesterol in blood and polyunsaturated fats are needed for heart health and brain function. Trans fats are unsaturated fats that have undergone processing and lead to increases in bad cholesterol levels and decrease good cholesterol levels in the body

Question 25

Digestion of protein

Answer 25

Digestion of protein begins in the stomach where pepsin and hydrochloric acid are released. Hydrochloric acid denatures the protein and the pepsin begins to break down some of the proteins into amino acids. The pepsin is deactivated when the chyme enters the small intestine enters the small intestine because it is too acidic for pepsin. Instead, the pancreas releases pancreatic juices containing pancreatic protease that break down the proteins into amino acids.

Question 26

Absorption of protein

Answer 26

Amino acids are absorbed into the bloodstream via the villi in the small intestine to the liver. From the liver, the amino acids are transported to where they are needed around the body or converted into glucose as a source of energy. The body can store excess protein as fat.

Question 27

Utilization of protein

Answer 27

Assist with growth, repair and maintenance of cells, form the basis of bones, blood, cartilage, muscles and skin, helps make hormones and enzymes, used as a source of energy when carbohydrates are not available.

Question 28

What are prebiotics?

Answer 28

Prebiotics are not bacteria. Prebiotics are fibre compounds that come from plant sources. They promote the growth and health of the microbiota. They are non-digestible carbohydrates that are not absorbed by the small intestine and enter the large intestine. The good bacteria in the gut feeds on these prebiotics, enabling them to produce energy and nutrients for the cells in the large intestine, creating a healthy digestive system. Fermentation occurs when the microbiota breaks down the non-digestible carbohydrates into short-chain fatty acids. The right balance of SCFAs provide energy for the cells in the gut and other health benefits. However, if an imbalance occurs where there is too much of one type of bacteria or not enough of another, adverse health consequences can result.

Question 29

Health benefits of short-chain fatty acids

Answer 29

Protection against inflammation, disease prevention and management, help control blood sugar levels and diabetes, synthesizing and absorption of vitamins and promote digestive health

Question 30

What are probiotics?

Answer 30

Foods that contain microorganisms that are alive and beneficial to health. Many fermented foods such as kefir, kimchi, kombucha, and sauerkraut contain probiotics. Probiotics add variety to the existing microbiota in the gut.

Question 31

Enteric Nervous System

Answer 31

The enteric nervous system is made up of millions of neurons found in the walls of the large intestine. The ENC works with the vagus nerve that runs from the brain to the intestines and the central nervous system. The vagus nerve and CNS communicate with the brain that creates a strong link between the gut and the brain. Because of this link, any disruption or imbalance in the gut microbiota can negatively impact a person's mental wellbeing.

Question 32

The production of hormones in the gut

Answer 32

Serotonin and dopamine are the "feel-good" hormones. The gut microbiota makes these hormones in much larger quantities than the brain can make. Serotonin is a chemical messenger that is believed to assist with mood stabilization while dopamine plays a role in pleasure, motivation and learning. Serotonin and dopamine levels in the body are likely to increase if various foods containing pre and probiotics are consumed.

Question 33

The role of diet in influencing gut microbiota

Answer 33

Diets high in processed foods, sugar, red meat and fast food feed the harmful bacteria in the gut whereas diets high in nutritious foods feed the good bacteria in the gut. Eating a diverse diet increases the range of microbiota in the gut whereas a lack of diversity will decrease it.

Question 34

Examples of prebiotics

Answer 34

Resistant starch and pectin such as undercooked pasta, under-ripe bananas, cooked and cold potatoes and rice. Apples, apricots and berries are excellent sources of pectin as they contain various short-chain fatty acids. Leek, garlic, berries, tomatoes, onion

Question 35

Credible sources

Answer 35

Educational institutes, experts in the field, government organizations, websites and campaigns and organizations

Question 36

Evidence-based information

Answer 36

Controlled randomised testing, food pattern modeling, systematic reviews, systematic literature reviews, peer-reviewed articles and meta-analysis

Question 37

Accurate analysis of data

Answer 37

Purpose of analysing data is to look for patterns, relationships or trends and come to a conclusion about the data. Evidence is usually graded such as Grade A, Grade B, etc. If data is incorrectly analysed, this could lead to researchers believing something that is not true.

Question 38

Credible sources for the ADGs

Answer 38

The ADGs were reviewed by a committee of leading experts in nutrition, public health and consumer issues and overseen by the NHMRC (National Health and Medical Research Council). These leading experts consulted with other experts in food, health and nutrition around Australia and other parts of the world. They also sought feedback from members of the public, industry, government departments and health professionals.

Question 39

Evidence-based information used in the ADGs

Answer 39

A systematic literature review of evidence about diet, disease, food, and health, peer-reviewed over 55,000 pieces of published scientific research about diet, food, and health and the use of some Grade A evidence statements and Grade B statements that supported the recommendations

Question 40

Accurate analysis of data in the ADGs

Answer 40

The NHMRC employed an independent methodologist to ensure all the data and research conducted was accurate, non-biased and consistent.

Question 41

Antioxidants

Answer 41

Mostly found in plant foods. They are naturally occurring molecules that help to protect from harmful free radicals that cause disease and illness.

Question 42

Free radicals

Answer 42

Dangerous molecules that can damage cells. Play a role in deterioration of the eyes, inflammation of the joints, damage to the brain, ageing, increased risk of cardiovascular disease and some cancers.

Question 43

Phytochemicals

Answer 43

Naturally occurring chemicals in plant foods that act in a similar way to antioxidants by stopping free radicals causing damage in our bodies.

Question 44

What are the ADGs?

Answer 44

To achieve and maintain a healthy BW by being physically active and consuming nutritious foods and drinks to meet energy needs, enjoy a wide variety of nutritious foods from the 5 food groups everyday, limit intake of foods containing saturated fats, sugar, salt and alcohol, encourage and support breastfeeding and care for food by preparing and storing it safely

Question 45

Rationale of the ADGs and the AGTHE

Answer 45

Rationale: To provide resources to help teachers, food makers, stores, health workers, policy-makers, and the public learn about nutrition and wellbeing. Providing reliable and trustworthy information about diets and nutrition. Aim to: Reduce the incidence of type 2 diabetes, cardiovascular disease and some cancers. Encourage and inform Australians about how to make healthy food choices.

Question 46

Food selection and prevention of obesity

Answer 46

Eat less processed and sugary foods - contain high amounts of hidden fat, salt and sugar Eat more servings of vegetables and fruit - keep feeling of fullness for longer, regulate blood sugar levels and are low in kilojoules Eat more fibre - contribute to satiety, reducing the likelihood of eating energy-dense foods (discretionary foods) Eat low glycemic index (GI) foods - if low in kilojoules, low GI foods may help people lose weight

Question 47

Food selection and prevention of type 2 diabetes

Answer 47

Eat a diet low in fat, particularly saturated fats Eat a diet low in sugar Eat low GI foods Eat regular meals and eat carbohydrate foods throughout the day

Question 48

Food selection and prevention of cardiovascular disease

Answer 48

Decrease the consumption of LDL cholesterol and increase consumption of HDL cholesterol Replace saturated and trans fats with unsaturated fats Eat foods that contain more fibre, particularly soluble fibre (dissolves in water) Reduce salt intake

Question 49

Food selection and prevention of some cancers

Answer 49

Eat more wholegrains Eat less processed and red meats Eat a variety of different types and coloured fruits and vegetables Consuming a high-fibre diet

Question 50

How does sex affect dietary requirements?

Answer 50

From birth to late childhood, there are little differences. From adolescence to old age, men and women have different dietary needs. Men generally need more energy (kilojoules) and more macronutrients due to a larger body, high BMR and greater muscle mass whereas women need less energy as they tend to be smaller than men, having a lower BMR and less muscle mass.

Question 51

How does activity level affect dietary requirements?

Answer 51

The amount and intensity of a person's activities can increase their BMR and increase their food energy needs. Incidental activity includes walking from class to class or doing chores whereas intentional exercise involves doing activities to be active on purpose.

Question 52

Dietary requirements for babies - birth to 6 months

Answer 52

Babies usually double their length and tripe their weight between birth and 1 year. Babies often consume exclusively breastmilk or formula. While formula provides a range of nutrients, it cannot copy the properties of breastmilk. Breastmilk contains all the nutrients the baby needs such as carbs, minerals, calcium, protein, unsaturated fats, vitamins and water. It also contains antibodies that are in large quantities just after birth and continue to be produced in smaller quantities as long as breastfeeding continues.

Question 53

Dietary requirements for infancy - 6 months to 2 years

Answer 53

Solid foods are usually introduced around this age. Foods that contain iron and zinc are particularly important as babies are usually born with enough but only for the first 6 months. They also require protein for growth, calcium for bone development, carbs for energy, unsaturated fats for energy and brain development and water for hydration.

Question 54

Dietary requirements for children - 2 to 11 years

Answer 54

Continues to develop but not as much as in infancy. They need more protein for bone and muscle development, calcium for bone growth and energy needs depend on amount of activity of the child.

Question 55

Dietary requirements for adolescents - 12 to 18 years

Answer 55

Adolescence is a time of rapid growth. Protein is required to support growth and muscle development, carbs are needed for energy, calcium for bone development and nutrients such as vitamin B6 and zinc are necessary for hormone production, mood balance and skin health. Males tend to have higher dietary requirements compared to females as they usually have a larger stature and faster metabolism than females. However, females require more iron because they menstruate.

Question 56

Dietary requirements for early adulthood - 19 to 50 years

Answer 56

As young adults leave school and join the workforce, usually in sedentary work, they become less active. They may also begin to drink alcohol and stop playing sports which may lead to weight gain.

Question 57

Dietary requirements for middle to late adulthood - 51 to 70 years

Answer 57

Usually have little time for health and wellbeing. Energy needs at this time usually decrease due to having a lower BMR and adults must be mindful of portion sizes. At this stage in life, women need more calcium. This is because women stop menstruating around the age of 50, producing less oestrogen which results in less calcium absorption. This makes women more susceptible to weakened bones and therefore, need more calcium.

Question 58

Dietary requirements for pregnant women

Answer 58

Pregnant women need more protein as it it needed for the proper growth of the baby's tissues and organs. They also require more iron for blood, particularly in the last 3 months of pregnancy because the baby takes enough iron from their mother's body to last them the first 6 months of life. Folic acid protects against neural tube defects in unborn babies which could cause paralysis. Iodine is an essential mineral needed for thyroid hormone production which decreases risk of baby having a mental impairment. There is no need for calcium increase as the pregnant woman's body absorbs more calcium during pregnancy.

Question 59

Dietary requirements for lactating women

Answer 59

Breastfeeding women need to consume a wide variety of nutrient dense foods containing calcium, iron, protein, vitamins and energy. Producing milk for a baby requires a large amount of energy so carbohydrates and unsaturated fats help with the energy requirement. Calcium is significant because if a woman's diet does not contain enough calcium, it is extracted from the bones, potentially causing weakened bones and woman’s risk of osteoporosis later in life. They also need to consume enough iron to replenish the supply in their bodies that was depleted during pregnancy. They must also drink more water as it is a significant part of breastmilk.

Question 60

What is a food allergy?

Answer 60

A food allergy occurs when the body’s immune system reacts to an allergen in food by making antibodies to destroy the food because it is harmful. The body often responds in the same way when the food is eaten again. The severity of the response usually increases each time a person is exposed to the allergen. Common allergens include eggs, fish, peanuts, shellfish, tree nuts

Question 61

Symptoms of food allergy

Answer 61

Abdominal pain, difficulty breathing, itchy rashes, swelling and tingling sensation around the mouth, throat and tongue, vomiting and anaphylaxis

Question 62

What is a food intolerance?

Answer 62

A food intolerance is a chemical reaction where it occurs in some people when the body produces insufficient amounts of the enzymes needed to digest specific types of food. It can take up to 12 or more hours after eating food for symptoms to appear. The degree of response depends on the amount of food consumed. The reaction is likely to be mild if a small amount was consumed whereas if a large amount of consumed, the symptoms would be more severe. Common intolerances include FODMAP, gluten and lactose

Question 63

Symptoms of food intolerance

Answer 63

Asthma, bloating, breathing problems, diarrhoea, headaches and migraines, stomach pain and sweating.

Question 64

Gluten intolerance

Answer 64

Gluten is a protein found in barley, oats, rye and wheat. This is different from coeliac disease as that occurs when gluten damages the villi in the small intestines, causing similar pain.

Question 65

Lactose intolerance

Answer 65

Lactose is the naturally occurring sugar in dairy products. Lactose intolerance occurs when the small intestine does not produce enough lactase to fully digest the lactose in dairy products.

Question 66

FODMAP intolerance

Answer 66

FODMAPs are often referred to as short-chain carbohydrates. FODMAP-sensitive individuals find it difficult to absorb these short-chain carbohydrates in the small intestine so they move into the large intestine, where bacteria use them as an energy source. As a result, significant amounts of flatulence and digestive discomfort are caused.

Question 67

Foods high in FODMAPs

Answer 67

Apples, peaches, broccoli, onions, honey, dairy milk, types of beans, pasta, bread

Question 68

Foods low in FODMAPs

Answer 68

Kiwi, oranges, carrot, spinach, brown rice, oats, milk alternatives, beef, chicken, eggs