Additives are substances added to food to improve flavour, colour, and texture or to preserve foods to help extend the shelf life.
Adipose tissue is made up of fat-storing cells and is the primary site of fat storage in the body.
The aleurone is a single layer of cells between the endosperm and bran in wholegrains. It is officially part of the endosperm but during processing is lost along with the bran. It contains protein, fats, vitamins and minerals.
Amino acids are the building blocks of all proteins. There are 20 different amino acids that combine in different sequences to make all the proteins required for metabolism and growth. Our body can manufacture 12 of these amino acids from recycled proteins; however the other eight need to be derived from the food we eat.
Anaemia is the term used for a number of medical conditions when there is too little red blood cells, or they are too immature or do not contain sufficient haemoglobin to carry adequate oxygen to the tissues. The most common causes are nutrient deficiencies, excessive bleeding or red cell destruction.
Anthocyanins are natural pigments that occur in plants, fruits and vegetables. They give plants the blue and red colours as seen in blueberries and plums. They belong to a group of plant compounds called flavonoids, and are believed to behave as antioxidants.
Antioxidants assist in protecting your body against the damage caused by free radicals by neutralising them. Free radicals are very reactive compounds formed in the body due to both external factors such as smoking, exposure to the sun, air pollution and internal factors such as the body's normal metabolic processes and the immune system. Free radicals can attack healthy cells in the body leading to cataract development and other conditions of ageing. They are also thought to be involved in the development of many diseases including cardiovascular disease and cancer. The body makes its own antioxidants, but also makes extensive use of dietary antioxidants. Dietary antioxidants include:
- Vitamins such as vitamin C, vitamin E and beta-carotene (which is converted to vitamin A in the body)
- Minerals such as selenium, zinc and copper
- Phytochemicals (natural plant compounds) such as carotenoids (e.g. beta-carotene, lycopene and lutein), flavonoids and isoflavones
Ascorbic acid is the chemical name for vitamin C, as found in many fruits and vegetables.
Atherosclerosis is a build-up of plaque in the wall of the arteries causing narrowing and loss of elasticity. Plaque contains deposits of fats, cholesterol and cell waste products.
Basal metabolic rate (BMR)
BMR is a measurement of the level of energy required to maintain the bodys vital life functions. Measured when the body is at complete rest.
Bioavailability is the ease at which a substance can be absorbed from the digestive tract and into the bloodstream. The higher the bioavailability, the greater the absorption.
Body mass index (BMI)
BMI is a measure of a persons body size by calculating their weight in relation to their height. BMI = kg/m2
Bone density is a measure of the strength of a bone by determining the amount of minerals (e.g. calcium) in relation to the amount of bone. Bone density increases throughout childhood and adolescence to peak at about 30 years of age then slowly declines as we continue aging.
Bran is the outer layer of a grain. It is a good source of fibre, vitamins and minerals. The bran is present in wholegrain cereals and breads but is lost during the refining process that is used to make many products such as white bread.
Caffeine is a natural stimulant found in coffee, tea, chocolate and some energy drinks. As a stimulant caffeine may increase heart rate and alertness but can also cause insomnia and restlessness. Caffeine also acts as a diuretic and can cause dehydration and headaches.
We need calcium for strong bones and teeth. Calcium is found in dairy products, fortified soy drinks, green leafy vegetables, nuts and seeds.
Calories are a measurement of energy. One calorie is equivalent to 4.18 kJ.
Carbohydrates are the most readily converted energy source. Good sources include rice, bread, cereal, legumes, fruits and vegetables which also provide important nutrients. Additional carbohydrate sources include refined sugars, which do provide instant energy but unfortunately don't offer the nutrients that the more complex sources of carbohydrates do.
Carotenoids are the orange, yellow and red pigments found in plant tissue that allow it to carry out photosynthesis. When eaten, these pigments provide vitamins and antioxidants that have many health benefits in humans. Beta-carotenes are a form of vitamin A.
Catabolism is the breaking down of a larger molecule into a smaller molecule. For example the breakdown of carbohydrates to release energy.
Cellulose is an insoluble fibre that makes up the framework of plant cell walls.
Central obesity refers to the excess fat stored around the abdominal area including around the vital organs such as heart and liver.
Cholesterol is a sterol which is made by the body and is found naturally in animal products such as meat, eggs, poultry and dairy foods.
Cognition refers to mental functions such as the ability to think, reason, and remember.
Complementary proteins are the proteins supplied by different foods that combine together to supply all the essential amino acids. The proteins present in one food complement the proteins in another food to supply any essential amino acids that the other may be missing.
Complete proteins are foods that contain all the essential amino acids in levels required by the body and do not require other foods to supply any.
Dehydration occurs when body water loss exceeds intake. This generally occurs due to insufficient water consumption or increased water loss due to vomiting, diarrhoea or excessive sweating. Symptoms include thirst, headaches, dry lips, lack of concentration. Mild dehydration can occur before you notice any symptoms.
Diabetes mellitus is a disease caused by the inability of the body to control the amount of sugar (glucose) in the blood. Type 1 diabetes results from the bodys inability to produce insulin in the pancreas and Type 2 diabetes is due to the body cells developing resistance to insulin.
A diuretic is a substance that increases the production of urine thereby increasing the removal of water from the body. Caffeine is a naturally occurring diuretic.
Electrolytes are minerals which are needed to keep the body's balance of fluids at a healthy level and to maintain normal functions, such as heart rhythm, muscle contraction, and nerve impulse transmission. Electrolytes include potassium, sodium, calcium, and magnesium.
Emulsifiers are substances that have both water-soluble and fat-soluble portions. This feature allows oils and water to combine in a solution.
Endosperm is the inner part of the grain. It contains carbohydrate, protein and B vitamins.
Energy is the fuel we need from food to function and be active. Energy requirements vary depending on your age, body size and physical activity. It’s important to monitor your energy consumption as too much energy can lead to weight gain. Fat, protein and carbohydrates all provide energy (known as kilojoules or calories) in the foods we eat. Fats provide more energy per gram than protein or carbohydrates.
Endosperm is the inner part of the grain. It contains carbohydrate, protein and B vitamins.
Enzymes are substances that speed up chemical reactions. For example, in our body some enzymes help break down the food we eat and release energy.
Ergogenic aids are substances taken to improve physical or mental performance. There are several types of aids ranging from the legal such as creatine and caffeine to the illegal such as steroids and blood doping.
Essential amino acidsEssential amino acids are the amino acids that the body cannot synthesise itself in sufficient quantities for physiological needs and must therefore be acquired from the diet. There are 8 essential amino acids required for adults and 9 for children.
Essential fatty acids
Essential fatty acids are the fatty acids that the body cannot synthesise itself in sufficient quantities for physiological needs and must therefore be acquired from the diet. There are 2 essential fatty acids; linoleic acid which is an omega-6 and linolenic acid which is an omega-3 fat.
Fad diets are fashionable diets that generally do not result in long-term weight loss. Fad diets are often dangerous to your health if undertaken for a long duration as they often eliminate many important food groups from your diet. Common fad diets include The Atkins Diet, The Southbeach Diet and The Cabbage Soup Diet.
Fats (or lipids) are an essential source of energy in the diet as they:
- are a carrier for the fat soluble vitamins (A, D, E and K)
- form part of cell membranes
- provide a very concentrated source of energy
- provide the starting ingredient for some hormones
- provide essential fatty acids which our body cannot produce
However fat should be eaten sparingly as too much can lead to weight gain, heart disease and some cancers. The type of fat eaten is also important:
- Polyunsaturated and monounsaturated fats - (good) can help reduce cholesterol. They are found in sunflower, olive, canola oils and margarines as well as many nuts, seeds and soy foods. Omega -3 is an important polyunsaturated fat found in fatty fish such as salmon and in the ancient wholegrain Salba.
- Saturated and trans fats - ('bad') can raise cholesterol levels and therefore increase your risk of heart disease. Saturated fats are present in many foods and are generally found in higher amounts in animal-based products and commercially baked products. Trans fats can be found in margarine and baked goods such as biscuits and pastries. It is best to eat less of foods that are high in saturated fats and trans fats, or to select lean or low-fat alternatives.
Saturated fat is fat that consists of triglycerides containing only saturated fatty acid radicals. There are several kinds of naturally occurring saturated fatty acids, which differ by the number of carbon atoms, ranging from 3 carbons (propionic acid) to 36 (Hexatriacontanoic acid). Saturated fatty acids have no double bonds between the carbon atoms of the fatty acid chain and are thus fully saturated with hydrogen atoms.
Fibre plays a key role in preventing constipation, cancer and heart disease. Wholegrain breads, cereals, legumes, rice, pasta, fruit and vegetables are good sources of fibre. There are a number of different types of dietary fibre. The three major types are soluble fibre, insoluble fibre and resistant starch. (Although it is not actually a fibre, resistant starch is now being recognised as a member of the ‘fibre family’ due to its similar effects on the body.)
Soluble fibre is beneficial to help lower blood cholesterol levels and, in people with diabetes, helps to control blood sugar. Soluble fibre is found in fruits, vegetables, dried peas, soybeans, lentils, oats, rice and barley.
Because of its ‘bulking properties’, insoluble fibre helps keep us ‘regular’. Foods containing insoluble fibre include wholegrain and wholemeal wheat-based breads, cereals and pasta.
Resistant starch is a type of starch found in plant foods that escapes digestion in the small intestine. Resistant starch may provide similar benefits to other types of fibre, such as helping to prevent constipation. Foods containing resistant starch include firm bananas, roasted chickpeas, boiled long grain white rice, baked beans, cooked and cooled potato, as well as cornflakes.
Flavonoids are water soluble plant pigments and are a subgroup of the polyphenol group of plant compounds. Flavonoids are believed to function as antioxidants, and are produced by plants to assist in photosynthesis.
Flavours are added to processed food to enhance the taste. There are 3 main types:
- natural as they occur in nature
- nature identical synthesized in the laboratory and are identical to those that occur in nature
A food allergy is an abnormal reaction of the bodys immune system to a protein in food. When the body comes in contact with the food protein, substances are released which cause inflammation (redness and swelling) and the symptoms of an allergic reaction. The symptoms of a true food allergy may include: an itchy rash, swelling or burning around the mouth and throat, vomiting, stomach cramps, hives, diarrhoea, wheezing and eczema. Severe reactions may cause asthma and allergic shock (called anaphylaxis). The most common foods in Australia that are linked with allergic reactions are: eggs, cows milk and peanuts. Other foods include: fish, wheat and soy.
Food aversions are a strong desire to avoid certain foods. This is not a food allergy or intolerance but may come from an association to an unpleasant event in the past with a certain food.
A food intolerance is an adverse reaction (that does not cause an immune response) of the body to compounds found in a variety of foods. Common symptoms are irritation of the stomach or bowels, hives, mouth ulcers, nausea, nasal congestion and diarrhoea. Food intolerances may also cause tiredness, weakness, headaches, irritability and muscle aches. Intolerance may occur to salicylates, amines and monosodium glutamate (MSG).
To fortify is to add nutrients to a food in levels higher than were originally present. Fortification can be mandatory to prevent a widespread nutritional deficiency, for example folate in bread, or voluntary to balance the total nutrient profile of a food.
Free radicals refer to atoms that have unpaired electrons in their outer layers. Caused by pollutants, cigarette smoke, and the by-product of metabolism they are believed to contribute to tissue damage and aging. Antioxidants are believed to quench these free radicals and neutralise the harmful effects.
Fructose is a type of sugar that is found naturally in fruit and honey.
Functional foods are foods that have been manufactured to contain a specific compound to provide a particular health benefit. Also called nutraceuticals or designer foods.
The germ is the embryo of a grain and is rich in protein, good fats, minerals, vitamin E and B vitamins.
Glucose is a simple sugar derived from the breakdown of carbohydrates. Glucose is a major source of fuel for the body, particularly the brain.
Gluten is a protein found in wheat, rye, barley, triticale and possibly oats (dependant on cross-contamination during processing). It is the gluten that gives dough its sticky cohesiveness which is important in manufacturing many products such as bread.
The Glycaemic Index (GI) is a system of classifying carbohydrate foods based on their effect on blood glucose (sugar) levels. Foods are given a rating between 0 and 100. Carbohydrate foods can be classified as having a low, moderate or high GI. Low GI foods are those that have a slower, more constant affect on a person's blood sugar levels. That means, they break down slowly and generally provide a longer 'feeling of fullness'. Taking this into consideration, a diet based on low GI foods can be useful to prevent overeating and maintain more optimal blood sugar levels.
Glycogen is the condensed form that any unused glucose takes when it is stored in the liver and around muscles. It is then readily available as required.
Goitre is an enlargement of the thyroid gland due to iodine deficiency or malfunction of the thyroid gland.
Grams (g) are a unit of measurement. Often used in nutritional values for nutrients such as carbohydrate, protein and fibre.
Haemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the cells throughout the body.
Health claims show a relationship between a specific nutrient in a food and prevention of a particular disease or health related condition.
Heavy metals are minerals such as mercury and lead. They are named because they are relatively high in atomic weight. Many heavy metals are poisonous.
Hydrogenation is the addition of hydrogen to a monounsaturated or polyunsaturated oil, producing a more solid oil and is used to make spreadable fats and reduce oxidation to protect against rancidity.
Insulin is a hormone produced in the pancreas in response to increased blood glucose levels. Insulins primary role is to transport glucose from the bloodstream into the muscle and tissues.
Iron helps create healthy blood and carries oxygen around the body. Iron is found in legumes, wholegrain breads and cereals, green leafy vegetables, nuts, seeds and meat.
Isoflavones are a naturally occurring plant compounds that have similar structural properties to estrogen. Also known as phytoestrogens.
Jaundice is the yellowing of the skin due to excessive bilirubin build-up in the blood. This may be caused by high levels of red blood cell destruction.
Kilojoules are the current standard unit of energy measurement. One gram of fat contains 37 kJ, one gram of protein or one gram of carbohydrates contain 17 kJ.
Lactase is the enzyme produced in the small intestine that is required to breakdown lactose.
Lactose is the sugar found in milk. The body breaks it down to glucose and galactose.
Legumes are plants of the pea or pod family, including peas, beans and lentils. They are rich in fibre and protein.
Lycopene is a phytochemical found in fruit and vegetables which gives them a red pigment. Lycopene can be more easily absorbed by the body if it has been gently cooked.
Macronutrients are the key nutrients in the diet that provide us with energy. They are carbohydrate, protein and fat.
Metabolic syndrome is the term given to a group of risk factors which, when present, greatly increase an individuals risk of developing coronary heart disease or type-2 diabetes. These factors are insulin resistance (or high blood glucose levels), hypertension, abnormal blood lipids, and obesity.
Metabolism refers to the chemical processes that occur in our body that turn what we eat into energy. This energy can then be used for all activity including walking, talking, thinking and breathing.
Micrograms (ug) are a unit of measurement. Often used in nutritional values for nutrients such as folate and vitamin B12.
Micronutrients is the general name given to compounds that are needed in minute quantities to sustain a healthy body, such as vitamins and minerals.
Milligrams (mg) are a unit of measurement. Often used in nutritional values for nutrients such as calcium and iron.
Minerals are important for the formation of bones, teeth, blood and connective tissues. They play important roles in chemical reactions, as they are a component of enzymes. Minerals also regulate water balance, muscle contractions and nerve transmissions. They are required in the body in small amounts and must be obtained from food.
Nutrients are substances obtained from food that we require for metabolism or physiological processes. Carbohydrates, fats, proteins, vitamins, minerals, fibre and water are all nutrients.
Phytoestrogens are a type of plant chemical that have a similar structure to the hormone oestrogen, however they are not identical in their effects. Two major types of phytoestrogens are isoflavones and lignans. Phytoestrogens occur naturally in legumes, wholegrain cereals, nuts and seeds, and many vegetables and fruits
Plant based eating
This is an alternative term that is used to describe vegetarian eating, or eating a diet that consists of predominately plant foods.
Plant sterols (also known as phytosterols) are natural substances that can help lower your cholesterol. They exist in wood pulp and leaves, but are also found naturally in certain foods such as vegetable oil, nuts, legumes, corn, fruits and vegetables. You can obtain higher levels through enriched margarine spreads.
When consumed, plant sterols reduce the absorption of cholesterol from your intestines into the body. This includes both the cholesterol you eat (called dietary cholesterol) and that made by your liver, which enters the intestines through bile. Studies show that plant sterols can lower LDL (or 'bad') cholesterol in the blood by around 10 per cent.
Potassium and sodium work together in the body to regulate the balance between water and acidity in the blood. Potassium is also important for nerve function to the muscles which causes muscles (including the heart) to contract. If there is a deficiency in potassium, heart rhythm can be altered. Potassium can be found in fruits, vegetables, grain foods, meats and milk.
Protein is important for growth of body cells and makes up virtually every part of the body. Protein can be found in dried peas, soy and baked beans, peanut butter, nuts, eggs, cheese, lean meat, fish and wholegrains.
Recommended daily intake
Recommended daily intake (RDI) is the average daily amount of all known nutrients that need to be consumed to maintain good health.
Refined refers to the process where foods are stripped of their coarse outer layers and many nutritional aspects. For example, wholegrain wheat is refined to produce white flour.
Sodium is an electrolyte that helps maintain acid-base balance of the blood, helps regulate blood pressure and water balance in cells and aids in muscle contraction and nerve impulse transmission. However, too much salt can lead to high blood pressure and stroke. Highly processed foods such as crisps and processed meats usually contain large amounts of sodium.
Tempeh is a food made from fermented soybeans. It is high in protein and fibre.
Textured vegetable protein
Textured vegetable protein(TVP) is a meat substitute made from processed soybean protein (soy flour).
Tofu is a soft cheese-like food made by curdling soy milk. Also known as soybean curd.
Triticale is a hybrid of wheat and rye.
Vegan is the word that describes an individual who avoids all animal-derived foods from their diet, including honey and gelatine.
There are two main types of vegetarian diets:
'Lacto-ovo' vegetarian - which includes dairy products and eggs along with all plant foods, such as grains, fruits and vegetables, pulses and legumes, nuts and seeds.
'Vegan' - which consists only of plant foods, avoiding all animal products including honey and gelatine.
With some planning, both of these diets can provide sufficient nutrients for good health.
Vitamins are molecules that are needed in small amounts by the body for health and growth, and they must be obtained by the diet daily. The exceptions to this rule are vitamin D, which is made in the skin when exposed to sunlight and vitamin K, which can be synthesised by gut bacteria in small amounts. Vitamins play an essential role in releasing energy from food and in speeding up many chemical reactions that occur in the body every second. They also play important roles in the formation of body components, such as blood and bone as well as being antioxidants.
Vitamin A is essential for a variety of functions including vision, skin health and new cell growth. Good sources include tomatoes and dark green and orange vegetables and orange fruits, such as broccoli, spinach, carrots, pumpkin and apricots.
Vitamin B1 (thiamin)
Vitamin B1 is needed for energy metabolism and the proper functioning of the nervous system. Good sources include wholegrains, soybeans, peas, beans, pistachio nuts.
Vitamin B2 (riboflavin)
Vitamin B2 is needed for energy metabolism, tissue growth, and maintaining good vision. Good sources include dairy products (milk, cheese, yoghurts), broccoli, spinach, mushrooms and eggs.
Vitamin B3 (niacin)
Vitamin B3 is needed for energy metabolism, proper digestion, and a healthy nervous system. Good sources include kidney beans, peanuts, mushrooms, milk, cheese, chicken and salmon.
Vitamin B6 (pyridoxine)
Vitamin B6 is needed for amino acid metabolism, cognitive function and immune function. Good sources include wholegrains, spinach, broccoli, carrots banana and yoghurt.
Vitamin B12 is an essential vitamin required by the body to make red blood cells and DNA. It is also needed to make a protective layer around nerve cells. This vitamin is found naturally in animal products, such as meat, dairy products and eggs. There are some plant sources of vitamin B12, however the form of the vitamin found in these foods is inactive and not useful to the body. People who only eat plant foods (i.e. vegans) should include adequate amounts of plant foods that contain added vitamin B12 (e.g. fortified soy drinks and soy-based meat-alternative products), or take a B12 supplement.
Folate (folic acid)
Folate is a B vitamin, essential for all the family, as it has an important role in the development of all body cells. It is especially important during periods of rapid growth. All women planning pregnancy or who might become pregnant should increase their intake of folate. This is because an adequate folate intake in the month before and the first three months of pregnancy may reduce the risk of babies being born with certain birth defects, such as Spina Bifida. Good sources of folate include fortified breakfast cereals and breads, dark green leafy vegetables, some fruits and juices (e.g. bananas, oranges and rockmelon), legumes (e.g. chickpeas) and nuts (such as peanuts).
Vitamin C is an antioxidant vitamin needed for the formation of collagen to hold the cells together and for healthy teeth, gums and blood vessels. It also improves iron absorption and resistance to infection. Fruit and vegetables are good sources of vitamin C.
Vitamin D promotes absorption and use of calcium and phosphate for healthy bones and teeth. The body synthesises vitamin D when our skin is exposed to at least 10-15 minutes sunshine per day. Longer time is required in winter months and in those with darker skin tones. Food sources include fortified milk, cheese, whole eggs, liver, salmon, and fortified margarine.
Vitamin E is a strong antioxidant that can help protect the bodys cells against damage. Food sources of vitamin E include wholegrain products, nuts and seeds, wheatgerm and vegetable oils.
Vitamin K is necessary for normal blood clotting and synthesis of proteins found in the bone and kidneys. About half of an individuals vitamin K requirements come from bacteria that reside in the gastrointestinal tract. The other half can be obtained from foods such as leafy green vegetables and cruciferous vegetables such as cabbage.
Waist circumference is a measurement of the size of an individuals waist.
Waist-to-hip ratio is measurement of an individuals waist divided by their hip measurement.
Water is one of the nutrients that our body requires for health and it makes up 50-70% of our body weight. All cells in the body require it and adequate water intake helps prevent dehydration. 6-8 glasses of water are required each day, more than this may be required during hot weather or for active people. Signs that a person may be dehydrated, even slightly include: inability to concentrate, confusion, tiredness, moody, dark coloured urine or dried cracked lips. People are often already slightly dehydrated before they begin to feel thirsty.
Wholefoods are foods that are unprocessed, or minimally processed and as such contain high levels of nutrients. Good examples of wholefoods include fruit and vegetables, wholegrains, brown rice, nuts and seeds.
The word 'wholegrain' refers to a grain food where all parts of the grain (the germ, endosperm and bran layer) are intact and retained. Examples include wholegrain wheat and wholegrain (brown) rice. If the grain has been cracked, crushed or flaked, then in order to be called 'wholegrain', it must retain nearly the same relative proportions of bran, germ and endosperm as the original grain.
Zinc is an essential mineral for human beings and is part of many reactions in the body. It plays a role in wound healing, our ability to taste and in growth and reproduction. Good plant sources of zinc include rolled oats, unprocessed bran, rice, muesli, wholegrain breads and cereals. Zinc is also found in a range of animal foods including oysters, beef and offal, with smaller amounts present in white meat and fish.