FHSN1030- summary sheet PDF

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FHSN1030- summary Unit 1: What is health: Health is often defined as the absence of disease or illness. The World Health Organization (WHO) was founded in 1948 and expanded the common definition to “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. Rene Dubos, French-American scientist and writer, refined the WHO definition in 1968 to “Health is a quality of life, involving social, emotional, mental, spiritual and biological fitness on the part of the individual, which results from adaptations to the environment.” This definition leads to the current ideas: a) that individuals are responsible for their health, b) the importance of an individual’s ability to cope with or adapt to life’s challenges, c) preventative action. What is wellness? The quality or state of being healthy in body and mind, especially as the result of deliberate effort. Wellness is an active and deliberate process involving conscious effort. Good physical, mental and emotional health, especially when maintained by an appropriate diet, exercise, and other lifestyle modifications. Since WWII, enormous strides have been made in individual and public health. Vaccination programs and antibiotics have reduced the occurrence of many diseases. Research into the links between smoking, diet and exercise coupled with the development of antihypertensive and cholesterol-lowering drugs has resulted in a reduction in cardiovascular diseases. Governments since the 1970s have begun to invest large amounts of money into preventive health campaigns in an attempt to limit the health costs associated with “lifestyle diseases” (also known as “diseases of affluence”) such as obesity, type II diabetes, heart disease, stroke, alcoholism and some cancers. Government suggest strategies to reduce such things, e,g reduce child’s intake of junk food. Do this through such campaigns: munch and move, national close the gap day etc Unit 2: What is nutrition: “the science of food, the nutrients and the substances therein, their action, interaction, and balance in relation to health and disease, and the process by which the organism ingests, absorbs, transports, utilizes, and excretes food substances” WHOs definition: “Nutrition as the intake of food, considered in relation to the body’s dietary needs. Good nutrition – an adequate, well balanced diet combined with regular physical activity – is a cornerstone of good health. Poor nutrition can lead to reduced immunity, increased susceptibility to disease, impaired physical and mental development, and reduced productivity.” What is a diet: refers to all the food and drink we consume: Our diet provides all the nutrients and other substances required by the body to grow and maintain our health and prevent disease. Healthy diet outcomes: has variety, balance and moderation. Gives you energy, vitality, grow and develop to your potential, physically, intellectually and physiologically, remain a healthy weight, boost immunity, prevent illness e,g heart disease, stroke, certain cancers, mature-age onset diabetes (Type II), anaemia and gall bladder disease Delays the effects of ageing, Builds strong dense bones – prevent osteoporosis, Improves your capacity to exercise and stay fit and your sports performance, Protects your teeth and keep

your gums healthy, Enhances your ability to concentrate, Possibly enhances your mood For women: helps to have healthy pregnancies and healthy babies. The Australian Dietary Guidelines were developed by the National Health and Medical Research Council (NHMRC) and are based upon current scientific research. The latest guidelines were released in 2013. 5 guidelines:1.To achieve and maintain a healthy weight, be physically active and choose amount of nutritious food and drinks to meet your energy needs. 2. Enjoy a wide variety of nutritious foods from the five food groups daily and drink plenty of water. 3. Limit intake of foods containing saturated fat, added salt, added sugars and alcohol. 4. Encourage, support and promote breastfeeding. 5. Care for your food; prepare and store it safely. 5 food groups: 1. Vegetables and legumes/beans. 2. Fruit.3. Grain (cereal foods), mostly wholegrain and/or high fibre cereal varieties. 4. Lean meat and poultry, fish, eggs, tofu, nuts and seeds and legumes/beans. 5. Milk, yoghurt, cheese and/or alternatives, mostly reduced fat. Guidelines aren’t a pyramid anymore, now a healthy eating plate, which shows the five food groups and proportions. Also note that legumes/beans appear in two of the five food groups. Consequences of a poor nutritional diet:

Standard serve sizes do not change – but different individuals will require a different number of serves per day

The recommended number of serves of each food group for adults depends on: 

age



gender



whether pregnant or breastfeeding



physical activity level Males have higher food intakes than females. Older people require less than younger people (except for milk products). Nutritional needs are higher in pregnancy and when breastfeeding. What are discretionary choices? Discretionary choices are “extra” foods that can form part of an individual’s diet. The amount of these foods should be limited. What does a healthy diet provide? A healthy diet provides: • Just enough energy to meet your energy needs (energy expenditure) and to maintain a healthy body weight • Sufficient nutrients to prevent nutritional deficiencies • some nutrients and other substances in quantities that decrease the risk of diet-related chronic diseases What are Nutrients: chemical substances obtained from food that are vital for the growth, performance and maintenance of a healthy body throughout life. Nutrients 1. are essential for health – our bodies can’t make them provide energy, 2. Provide building blocks, 3. Maintain body cells, 4. Regulate body processes. Note that: Energy is not a nutrient and alcohol is not a nutrient. Nutrients are divided into 2 main categories – macronutrients and micronutrients. Macronutrients are needed in large quantities (such as grams) and are typically large molecules. Micronutrients are required in smaller quantities (milligrams or micrograms) and are typically smaller molecules. These two categories can be further divided into the 6 categories of nutrients. Macronutrients – carbohydrates, fats and proteins, Micronutrients – vitamins, minerals and water. Nutrients three functional groups: 1. Provide energy and building blocks (proteins, most carbohydrates, most lipids (fats)) 2. Promote growth, development and

maintenance (proteins, lipids, some vitamins, some minerals, water) and 3. Regulate body processes (proteins, some lipids, some vitamins, some minerals, water). Unit 3: What is energy? Energy is not a nutrient, but it is released from food via chemical reactions during digestion. The macronutrients (carbohydrates, proteins and fats) are also known as the energy nutrients since they contribute energy to the body. Alcohol also contributes energy to the body, but it is not a nutrient as it does not provide any nutrition, hence it is often referred to as “empty calories”. The metric unit of energy is Joules (the old measure was calories). 1000 joules (J) = 1 kilojoule (kJ) Calories: 1 kilocalorie = 1000 calories = 1 Calorie (note the capitalisation). 1 Calorie = 4.18 kJ Energy in macronutrients and alcohol

What are carbohydrates? Carbohydrates are chemical compounds made up of carbon, hydrogen and oxygen atoms. They can be divided into 2 categories; complex carbohydrates (such as starches) and simple carbohydrates (sugars). Carbohydrates are broken down during digestion to glucose which is the body’s (especially the brain’s) main source of fuel. Examples include: bread, rice, pasta, potatoes and sugar. There are 6 simple carbohydrates: Monosaccharides (“mono” meaning one sugar unit) Glucose (Blood Sugar), fructose (Fruit and Honey Sugar), Galactose (Part of Milk Sugar) Disaccharides (“di” meaning two sugar units, formed by the combination of 2 monosaccharides) Sucrose (Table Sugar), lactose (Milk Sugar), Maltose (Malt Sugar, used in brewing) The important disaccharides in nutrition are sucrose, lactose and maltose. All contain glucose. Sucrose (Glucose + Fructose) – Table Sugar, Lactose (Glucose + Galactose) – Milk Sugar Maltose (Glucose + Glucose) – Malt Sugar Once digested into monosaccharides and absorbed, the fructose and galactose are converted to glucose by the liver. Complex carbohydrates are also known as polysaccharides. Poly is Greek for “many” since they contain many monosaccharide units joined together.

Glycogen, starch and dietary fibre are the three most important complex carbohydrates in nutrition. What is glycogen? Glycogen is a storage molecule found in the muscles and liver. Starch usually consists of around 3000 glucose molecules joined together and is a good energy source for the body. What is dietary fibre? Dietary fibre is indigestible plant material. It can be divided into insoluble (such as cellulose) and soluble fibre (such as the fibre found in fruit, vegetables, gums, and psyllium). What is protein? Proteins are chemical compounds made up of carbon, hydrogen, oxygen and nitrogen atoms. Some sulfur is also found in proteins. Examples of proteins include: meat, fish, eggs, milk and nuts. Protein accounts for around 17% of body weight. Proteins are made of units called amino acids. There are 20 amino acids and 9 are considered “essential”. This means that they cannot be manufactured by the body and must come via diet.

What is complete proteins? Proteins containing all essential amino acids in the correct proportions for use by the body are known as complete proteins or “high quality” proteins. Complete proteins are only found in animal proteins (meat, milk, eggs), soy and quinoa. Incomplete (or “low quality”) protein is deficient (i.e. it may be present but in low amounts) in at least one essential amino acid. By eating a variety of foods, a full complement of amino acids can be attained through the diet. Plant protein can be of low quality – even staple foods are deficient: •

Wheat in lysine

•

Rice in threonine

•

Corn in tryptophan

•

Legumes in methionine, cysteine, tryptophan

Therefore, this is an important issue in vegetarian diets, especially vegans, who do not eat milk and eggs. Some animal proteins are also incomplete, e.g. gelatine, an incomplete animal protein, no tryptophan at all and low in isoleucine, threonine and methionine. Protein has varied roles in the body including, regulating body processes (hormones, neurotransmitters and enzymes), promoting growth and development (muscles and other tissues), fighting infections (antibodies),

transporting nutrients (haemoglobin carries oxygen to cells), fluid balance (albumins and globulins in blood), acid-base balance (protein buffers) - rather than being used for energy. Using protein as an energy source places a large stress on the liver and kidneys and is generally avoided by the body unless there is limited supply of carbohydrates. Most individuals eating a standard Western diet consume more protein than is required each day. The amount of protein needed each day is 0.8 g of protein / kg of healthy body weight for an average person. Excess protein is stored in the body as fat. Individuals who undertake regular vigorous exercise have higher protein requirements (1.5 – 2 g / kg). Pregnant and breastfeeding women also have higher protein requirements. What are fats? fats are known as lipids. They are chemical compounds made up of carbon, hydrogen, oxygen and nitrogen atoms. Many fats are known as triglycerides and consist of a glycerol unit and 3 fatty acids. There are two essential fatty acids – these must be consumed in the diet. They are linoleic acid (“omega-6”) and linolenic acid (“omega-3”). The balance between the omega-3 and 6 compounds is important for conditions involving inflammation like arthritis. The ratio should between 5:1 and 10:1. These are needed for immune function, vision, and for the production of hormone-like compounds and are a structural component of cell membranes. The hormone-like compounds made from the essential fatty acids are important for regulating blood pressure, body temperature, pain, childbirth, clotting, stomach secretions, the immune system defence against infections and allergic and inflammatory reactions. Triglycerides are the main form of energy storage in the body. If a lipid is a solid at room temperature, it is called a fat and if it is a liquid at room temperature, it is called an oil. Triglyceride properties differ due to differences in the length of the fatty acids (more or less atoms in the chain) and due to the type of chemical bonding (single or double carbon bonds). If a lipid has double bonds in its chains, it is called “unsaturated”. If it has one double bond, it is called “monounsaturated” (such as olive oil and avocado oil) and if it has multiple double bonds then it is called “polyunsaturated” (such as sunflower oil, safflower oil, canola oil and linseed oil). These all tend to be liquids at room temperature (i.e. oils). If a lipid has single bonds in its chains then it is known as a saturated fat and tends to be solid and room temperature. Animal fats are high in saturated fat, as are palm oil and coconut oil. What are trans fatty acids? Trans fatty acids have a slightly different chemical structure to most fatty acids (which are known as cis fatty acids). Due to this structure, they are treated differently by the body and can raise blood cholesterol, like saturated fatty acids. Trans fatty acids occur naturally in low levels but are found in much higher concentrations in manufactured fats and oils, such as margarines, shortening and many commercially prepared baked goods. They are often labelled as “hydrogenated oils”. Cholesterol is also a lipid. It is an essential component of cell membranes (with phospholipids, allows fat soluble compounds in and out). o Produced by the liver o Found only in animal products o Forms important hormones (oestrogen, testosterone, vitamin D)

o Precursor to bile acids (made by liver – emulsifiers) o Aids with transport of lipids/triglycerides in the bloodstream o Sources of cholesterol: foods of animal origin only o We obtain one third of our cholesterol from the diet, unless you are a complete vegetarian (vegan), o The rest (two thirds) we make ourselves, therefore cholesterol is not an essential nutrient o 40-60% of dietary cholesterol is absorbed o Plant sterols (phytosterols) – in plant foods and margarine (e.g. ProActive) reduce body’s absorption of cholesterol and lower blood cholesterol o Saturated fatty acids and trans monounsaturated fatty acids raise blood cholesterol o Polyunsaturated and cis monounsaturated fatty acids decrease blood cholesterol The “Standard Adult” dietary requirement is 8700 kJ per day. This is defined by our government law in the Food Standards for Australia and New Zealand (FSANZ) Code 1.1.1

The 60:30:10 rule comes from the calculated nutrient requirements for a standard adult. 55-65% of energy from Carbohydrates (with ≤10% from refined sugar) ≤30% of energy from Fats (with 100 mg/day. By abundance in the human body they are Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chloride and Magnesium Trace minerals require < 100 mg/day. By requirement Iron, Zinc, Iodine, Selenium, Copper, Manganese, Fluoride, Molybdenum, Chromium The mineral content of food is also affected by food processing:

The more refined a plant food is, the lower its mineral content, e.g. milling removes iron, zinc, selenium, copper Fortification will increase the content (e.g. iodine and calcium fortification). Commonly fortified foods include bread (flour), milled products (breakfast cereals) and salt (iodine) Cooking equipment (Iron), sanitising compounds (Iodine), food additives (Iron) can increase levels The most common mineral deficiencies are: Major Minerals: Calcium (young girls, post-menopausal women, elderly men) Potassium, Magnesium. Trace Minerals: Iron (pre-menopausal women), Zinc, Iodine (in areas with poor soils including Australia) Mineral toxicity levels: Especially with trace minerals (Fe, Zn), need careful use of mineral supplements. Three of the seven major minerals and all the trace minerals except chromium, have an upper intake level (UL). High intakes of one mineral can inhibit the absorption of others. Contamination, e.g with lead from industrial contamination Water: o Most abundant compound in our bodies o We can’t store it nor conserve it so we need to regularly replenish it – the need for it is recognised as thirst o Needs vary with physical activity, environment, nutrient intake, diuretics (things that make you urinate including alcohol and coffee), individual differences o Has unique chemical and physical properties which enable biochemical reactions which allow us to be alive and function on Earth o Water content is highest in infants and children (80%); declines with age; ~55% in adults, ~50% in elderly o Lean tissue contains 73% water; adipose tissue, only 20% o Water in intracellular (inside cells) and extracellular (outside of cells) compartments contains dissolved solutes (the electrolytes) which keeps our electrical and cellular functions going How much water is in the body? Intracellular fluid (fluid with the cells) = 63% = 25 L Extracellular fluid (fluid outside the cells, comprises interstitial and intravascular) = 37% Interstitial = 11L (between cells, gastrointestinal fluid, spinal column fluid, fluid in eyes, tears, synovial (joints) fluid) Intravascular (blood and lymph) = 4L Total Water in the Body ~40L Functions of water: o o o o o o o o

Maintenance of blood volume, transport of nutrients and important body compounds Important for digestion of food and absorption of nutrients Solvent and reactant in metabolic processes Body temperature regulation - water absorbs any excess heat & body secretes fluids via perspiration Important to allow efficient functioning of enzymes Removal of body waste via urine (too concentrated urine can cause kidney stones to form) Excretion of urea (nitrogen containing by-product of the breakdown of excess protein) and excess sodium Amniotic fluid, joint lubricants, saliva, bile

Recommended: 1 ml per 1 kcal or 4 kJ

Age and gender dependent, body size, physical activity, environment, diuretics and dietary intake also effect water intake needs Adequate Intake (AI) is set to provide guidance only Total (fluid only is given in brackets after) – about 80% liquids, 20% foods Men >18y: 3.4L (2.6L) Women >18y: 2.8L (2.1L) Pregnant >18y: 3.1L (2.3L) Lactating > 18y: 3.5L (2.6L)

Non-nutrients are not digested or absorbed by the body. Dietary fibre is an example of a non-nutrient. Phytochemicals are also examples of non-nutrients. Phytochemicals: o Considerable research attention is focused on various phytochemicals in reducing the risk of certain diseases such as heart disease and cancer o Risks and benefits? For example: Soy isoflavones may have risks and benefits: risk of thyroid toxicity and goitre; benefits: reduced risk of breast cancer, osteoporosis and cardiovascular disease o The term “superfood” – food with a high content of certain phytochemicals said to confer health benefits – has recently been overused as a marketing ploy as there is little data to support the claims o Protect plants from disease and damage and contribute to the plant’s colour and flavour o Protect plants from environmental hazards such as pollution, stress, drought, UV exposure and pathogen attack o Accumulate in different parts of the plant – roots, stems, leaves, flowers, fruits or seeds. o Many, particularly the pigments, are concentrated in the outer layers of the various plant tissues o Levels vary from plant to plant depending on the species and varieties and on growing conditions o Phytochemicals in freshly harvested plant foods may be degraded by processing, so processed foods are likely to contain fewer phyt...