A to Z of Nutrition

Acidophilus is a probiotic bacteria which is commonly found in yogurt. Probiotic bacteria survive digestion in the stomach and help maintain the balance of ‘good bacteria’ in the lower parts of the intestinal tract. A good balance of ‘friendly’ bacteria in the intestine reduces the risk of health problems.

Additives are used to preserve food and/or improve its taste, appearance, quality and stability. Many of the substances used as food additives also occur naturally in foods. Food additives are listed in the ingredients list of packaged foods and are described by their function in the food, followed by either the specific name or the number unique to each additive e.g. emulsifier (322). Food additives are given code numbers to make them easier to identify as their names can sometimes be long and complicated. The type and level of additives used in foods in Australia is regulated by the Food Standards Code.

Amino acids are the building blocks of protein. There are 20 different types that are combined in different ways to make different proteins. The body can make some of its own amino acids but some are essential meaning that they cannot be made by the body so we need to get them from food.

Anaemia refers to a variety of conditions in which the concentration of haemoglobin, an oxygen carrying molecule in the blood, is reduced. Common symptoms of anaemia are tiredness and fatigue.
The most common causes of anaemia are iron deficiency, folate deficiency and/or vitamin B12 deficiency (pernicious anaemia).

Iron deficiency anaemia is the most common anaemia in Australia and can be caused by inadequate intake of iron containing foods. Iron containing foods include red meat, seafood, poultry, wholegrain breads and cereals, nuts, legumes and green leafy vegetables. The iron from meat, seafood and poultry is better absorbed than that from plant foods.

Another type of anaemia is pernicious anaemia which occurs when the body lacks intrinsic factor (the substance that helps the body absorb vitamin B12 from food). Pernicious anaemia is a result of vitamin B12 deficiency.

Antioxidants are compounds that help to protect the body against damage caused by free radicals. The body produces its own antioxidants and they are also found in foods such as fruits and vegetables, tea, coffee, dark chocolate and red wine. Common antioxidants are vitamins C, E and A, and phytochemicals like polyphenols. Eating a diet rich in antioxidants is beneficial for health and wellbeing.

Aspartame is an artificial sweetener made up of two amino acids – aspartate and phenylalanine. These amino acids are found naturally in many foods such as meat, vegetables, dairy products and cereal grains. Individually these amino acids are not sweet, but joined together they produce an intense sweet taste that is approximately 200 times sweeter than sugar.

The body mass index is a way of assessing whether a person is in the healthy weight range for their height. BMI is calculated by dividing your weight in kg by your height in metres squared (BMI = kg/m2). People with a BMI between 18-25 kg/m2 are considered a healthy weight, 25-30 kg/m2 overweight and over 30 kg/m2 obese.

Caffeine is a naturally occurring chemical found in plants. Common sources are coffee beans, tea leaves, guarana berries and smaller amounts are found in cocoa beans. Caffeine acts as a stimulant to the nervous system in the body, increasing mental alertness.

Calcium is a mineral that is an important component of our bones. Dairy foods such as yogurt, milk and cheese are rich sources of calcium, and it is also found in canned salmon and sardines with bones, some nuts, seeds and fortified foods such as soy products, orange juice and cereals.

Calories are a unit of energy. In Australia it is more common to use kilojoules (kJ) as the unit of energy. One Calorie is equal to about 4.18 kilojoules.

Carbohydrates are short or long chains of sugars that play an important role in the diet and are used to supply the body with energy. Sugar, starch and cellulose are all types of carbohydrates. Bread, cereals, rice, pasta, legumes, fruit and some vegetables are all good sources of carbohydrates.

Cardiovascular disease is a name given to a group of diseases that affect the heart and/or blood vessels and includes stroke, heart attack, angina and high blood pressure.

Chicory is a plant which has roots that can be roasted, ground and used to make a hot beverage. Chicory may be used as a coffee or tea substitute but unlike regular coffee and tea, chicory contains no caffeine.

Cholesterol is a fat-like substance that has important functions in the body including an integral part of the structure of cells and being used by certain glands for making sex hormones. There are two types of cholesterol in the blood: HDL (high density liproprotein) or ‘good’ cholesterol and LDL (low density lipoprotein) or ‘bad’ cholesterol. High levels of LDL in the blood can increase the risk of cardiovascular disease.

Diabetes is a condition in which the body has difficulty controlling the level of glucose (sugar) in the blood. There are three types of diabetes: type 1 (previously called insulin dependent) where insulin is no longer produced; type 2 diabetes mellitus (previously called non-insulin dependent) where the body does not respond well to insulin, or the insulin that is produced does not work properly; and gestational diabetes which is type 2 diabetes that occurs during pregnancy.

Dietary fibre is an indigestible form of carbohydrate of which there are three types, insoluble fibre, soluble fibre and resistant starch. Insoluble fibre helps keep the bowel regular by absorbing water which softens the bowel contents. It is mostly found in wheat based foods such as bread and cereals but is also in nuts, seeds, fruit and vegetables. Soluble fibre, found mostly in fruits, vegetables, oats, dried beans and peas, slows down the emptying of the stomach helping people feel full for longer. Resistant starch is starch that is not digested in the small intestine but moves to the large intestine where it is fermented by good bacteria to produce substances that help keep the lining of the bowel healthy.

Echinacea is a flowering plant often used as a herbal remedy to provide support for the body’s immune system and help reduce the risk of minor infections.

Electrolytes are the term used for minerals in solution. Some of the main electrolytes in the body are sodium, potassium, calcium, magnesium, chloride and phosphate. Minerals play an important role in processes within the body such as nerve and muscle function and fluid balance. Electrolyte levels in the body can be disturbed when large amounts of fluid are lost such as in vomiting, diarrhoea and heavy sweating.

Emulsifiers are food additives that are added to food to help mix oil and water ingredients. An example of a common emulsifier used in food is soy lecithin.

Carbohydrate, fat, protein, dietary fibre and alcohol are broken down to provide energy for the body. Food energy is measured in kilojoules (kJ) or calories (Cal). Our bodies need energy for body functions such as breathing and digestion, for everyday activities we do and any physical activity. Daily energy requirements differ depending on age, sex, body weight and activity levels. The average daily energy requirement for Australian adults is 8700kJ.

Essential fatty acids are types of fat that are needed for proper function and development but need to come from the diet as they cannot be made by the body. There are two essential fatty acids – linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid). Good sources of linoleic acid include polyunsaturated oils, margarines, some nuts (e.g. walnuts) and some seeds (e.g. sesame). Good sources of linolenic acid include canola oil, flaxseed and walnuts.

Fat is an essential macronutrient used by the body for functions like insulation, protecting organs, as a store of energy and to supply fat soluble vitamins (A, D, E and K). The types of fats include saturated fat, monounsaturated fat, polyunsaturated fat and trans fat. Nutritionists recommend limiting saturated fat and trans fat in the diet.

Flavonoids are a type of polyphenol, which is a group of plant chemicals with a similar chemical structure that act as antioxidants in the body. Sources include wine, grapes, apples, tea, onions and berries. Flavonoids are found in small amounts in most vegetables and fruit.

Flavours are a category of food additive that are added to food to impart a desired flavour. There are three classes of flavours, natural, nature identical and artificial.

Fluids refer to the amount of liquid that we need each day. Our bodies are made up of a high percentage of liquid, and we need to replenish our fluid losses regularly. Daily fluid needs depend on many factors such as age, environment and activity levels. We get fluids from both the food that we eat and the liquids that we drink.

Folate is a B vitamin that is occurs naturally in green leafy vegetables, fruits (e.g. bananas and oranges), legumes and peanuts. It is also added to some breakfast cereals. Folate is needed in the body for proper cell development. An adequate intake of folate pre-pregnancy and in the first three months can help reduce the risk of foetal neural tube defects.

Food Standards Australia New Zealand (FSANZ) is a statutory agency within the Australian Government’s Health and Ageing portfolio that sets food standards for Australia and New Zealand. FSANZ produces and updates the Food Standards Code. It is also responsible for food surveillance and food recall systems.

The Food Standards Code is a collection of standards that form the basis of the food laws in Australia and New Zealand. The standards cover such issues as naming, definition and labelling of food as well as what can and cannot be added to foods and the permitted levels of certain substances in foods. The Code is produced by Food Standards Australia New Zealand and enforced by State, Territory and New Zealand Health Departments.

Free radicals are highly reactive compounds that are produced within the body as a product of normal metabolic process and due to outside influences, such as smoking, air pollution and sunlight exposure. If the level of free radicals in the body is not controlled they can cause damage to cells. Antioxidants produced within the body or sourced from the diet help to control the level of free radicals.

Fructose is a monosaccharide (a sugar) which occurs naturally in fruit and honey. It is the sweetest naturally occurring sugar. Glucose and fructose are joined together to form the common sugar, sucrose. Fructose is also used as a sweetener in some processed foods.

Glucose is a monosaccharide (a sugar). Carbohydrate containing foods are broken down during digestion into glucose. The body’s cells use glucose to make energy to fuel the body. Sometimes the words blood glucose and blood sugar are used interchangeably.

Gluten is a type of protein found in cereal plants like wheat, barely, rye, triticale and oats. For some people, gluten is an allergen.

The Glycemic Index (GI) is a ranking of carbohydrate containing foods according to the effect they have on blood glucose levels. Low GI carbohydrates are broken down by the body slower and result in a more gradual rise in blood sugar levels. High GI carbohydrates are broken down more quickly and result in more rapid increase in blood sugar levels. A GI of less than 55 is considered low, 56-69 is considered medium GI and a GI of 70 or over is considered high. Low GI foods are useful for everyone, and particularly for those with type two diabetes mellitus, to help with control of blood glucose levels. High GI foods can be useful for sportspeople as a more rapid source of glucose to fuel working muscles. GI is best used to compare foods with similar carbohydrate contents, such as comparing one bread with another or one breakfast cereal with another cereal.

Glycemic load, like GI (Glycemic Index), is a way of ranking carbohydrate containing foods. However, the glycemic load takes into account both the GI of the food and the amount of carbohydrate in a serve of the food.

GL= (GI X carbohydrate per serve (g))  100

A GL of 20 or more is high, a GL of 11 to 19 inclusive is medium, and a GL of 10 or less is low.

Because it takes into account the amount of carbohydrate in a food, the GL is best used to determine the overall impact on blood glucose levels of foods of different types.

Genetically modified organisms are organisms that have been modified via the introduction of genetic material and proteins from another source. Food Standards Australia New Zealand (FSANZ) regulates the sale of all genetically modified (GM) food in Australia and New Zealand. All foods produced using GM technology must undergo a pre-market safety assessment and mandatory labelling requirements.

The iron found in animal products is called haem iron. ‘Haem’ iron is found in high amounts in red meat and offal. White meats such as fish and chicken also contain haem iron but in smaller amounts than in red meat. As a general rule of thumb, the redder the meat, the more iron. Haem iron is more efficiently absorbed by the body than non-haem iron which comes from plant sources.

Halal foods are those that are free from any component that is considered unlawful in Islam. They are processed, made, produced, manufactured and/or stored using utensils and equipment that have been cleansed according to Islamic law. There are several organisations in Australia that certify foods as foods as being Halal.

Hydrogenated fats are vegetable fats that have been chemically altered by the addition of hydrogen (hydrogenation) with the purpose of making them more solid. Turning a liquid oil into a more solid form makes it more stable for use in food manufacturing. Sources of hydrogenated fats include some cooking margarines, biscuits, cakes, pies and popcorn and many commercial frying oils.

Insoluble fibre is a type of dietary fibre that is found in cereals, the outer skins of some fruit and vegetables, nuts, seeds and often in high fibre breads. Insoluble fibre absorbs water in the large intestine which helps to soften bowel contents and promote regularity.

Insulin is a hormone that is produced by the pancreas in response to the food we eat. Insulin’s main role is to take glucose from the blood and move it into the body’s cells so that the cells can use the glucose for energy.

Inulin is a type of soluble fibre found in some plants. Inulin has a positive effect on the body by promoting the growth of beneficial intestinal bacteria. Because of this effect, inulin is known as a prebiotic.

Iron is a mineral that is used by the body to make haemoglobin, the part of the red blood cell that transports oxygen. Iron-containing foods include red meat, poultry, legumes, green leafy vegetables and whole grain breads and cereals. A lack of iron in the diet or poor absorption of iron can lead to iron deficiency anaemia.

Kilojoules (kJ) are a unit measure for energy. In Australia we use kilojoules as our standard measure, but Calories can also be used. 4.18 kilojoules is equal to around one Calorie.

Lactose is the sugar that occurs naturally in milk. It is a disaccharide that is made from 2 sugars joined together (glucose & galactose).

Carbohydrate, fat, protein and alcohol are called macronutrients. Macronutrients supply the body with energy. We need macronutrients (with the exception of alcohol) in larger amounts than vitamins and minerals which are called micronutrients.

Maltodextrin is a polysaccharide (long chain of sugars) produced from corn or wheat starch that is used as a food additive in many commercial foods including confectionery, snacks and desserts.

Micronutrients are essential nutrients such as vitamins and minerals that are required by our body in small quantities. Micronutrients are needed to help maintain proper health and functioning of the body.

Minerals are compounds that occur in rocks and metal ores. Plants absorb minerals through the soil, and animals get these minerals by eating the plants or by eating other animals. Some of the major minerals required by the body include calcium, phosphorus, magnesium, sulphur, potassium, chloride and sodium. Trace elements are minerals needed by the body in smaller amounts such as iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium, molybdenum.

Monosodium glutamate occurs naturally in some foods like mature cheeses, tomatoes, mushrooms and soy sauce. MSG also functions as a flavour enhancer and is sometimes added to savoury products like soups, sauces and stocks. It is displayed in the ingredient list as “flavour enhancer (monosodium glutamate)” or “flavour enhancer (621)”.

Monounsaturated fats are the ‘good fats’ and are found in avocados, nuts such as peanuts, almonds, cashews, macadamias and oils such as olive and canola.

The New South Wales School Canteen Association is an organisation that supports school communities to operate school canteens with the aim of increasing the number of nutritious foods available to school canteens. Nutrient criteria set levels of fat, salt, fibre and sugar in accredited foods, as well as selected nutrients such as calcium in some categories.

The iron found in plant foods is known as non-haem iron. Iron from plants is found in wholegrain breads and cereals, legumes, nuts and seeds and some vegetables like spinach. Non-haem iron is not absorbed by the body as well as haem iron from animal products. Eating foods rich in vitamin C with a non-haem iron containing food can help increase absorption of iron by the body.

Omega-3 fats are essential polyunsaturated fatty acids. Essential means that they cannot be produced in the body and therefore must be obtained from food. They can be classified into 3 different types: docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and αlpha-linolenic acid (ALA). EPA and DHA can be used directly by the body’s tissues. ALA can be converted to EPA and DHA in the body, however this is not very efficient, with only 15% of ALA converted to EPA and DHA.

Pectin occurs naturally fruit and it is often added to foods to thicken or stabilize them. Pectin is also used in throat lozenges because of its soothing properties.

Phytochemical or phytonutrient in broad terms means any chemical or nutrient derived from a plant source. There are hundreds of phytochemicals in plants and it is believed many are yet to be discovered. Phytochemicals are thought to be beneficial for general health. Some commonly talked about phytochemicals are antioxidants such as flavonoids in fruit and vegetables, lycopene in tomatoes and polyphenols in coffee and cocoa beans. Plant sterols (see phytosterols) are another type of phytochemical.

Phytoestrogens are naturally occurring plant chemicals that are similar in structure to the human hormone oestrogen. The most common phytoestrogens are the isoflavones found in soy beans and lignans from linseed. Phytoestrogens behave similarly to oestrogen in the body and are thought to help relieve some menopausal symptoms and potentially have other health benefits.

Phytosterols are compounds that have a structure like cholesterol and are found naturally in small amounts in foods such as vegetable oils, fruits, legumes and nuts. When consumed regularly in concentrated products such as phytosterol-containing margarines, they can help to lower cholesterol levels by reducing cholesterol absorption.

Polyphenols are naturally occurring plant chemicals, including flavonoids, catechins, isoflavonoids, lignans and anthocyanins. They are antioxidants which may help protect against oxidative damage and are most commonly found in some fruits and vegetables, tea, coffee, soy, seeds, lentils, some dark chocolate and red wine.

Polyunsaturated fats are ‘good fats’. There are two main types of polyunsaturated fats: omega-3 and omega-6. Omega-6 fatty acids are found in sunflower oil, some margarines, some nuts (e.g. walnuts), some seeds (e.g. sesame, sunflower) and legumes. Omega-3 fatty acids are found in oily fish such as mackerel, sardines, salmon and tuna as well as canola and soybean oil.

Potassium is a mineral that plays an important role in our nervous system and is found in fruits, vegetables, milk, and meat.

A prebiotic is a substance that promotes the growth of the beneficial bacteria in the intestine. Prebiotics work by providing food for the intestinal bacteria. Examples of prebiotics are inulin and fructooligosaccharides.

Preservatives are a type of food additive used to help prevent the deterioration of food by micro-organisms and preserve the food quality over an extended period of time.

Probiotics are bacteria that help replenish the beneficial bacteria in the intestine. Common foods that contain probiotics are yogurt and fermented milk drinks. Maintaining a balance of healthy bacteria in the intestine is beneficial for a healthy digestive system.

Probiotics are bacteria that help replenish the beneficial bacteria in the intestine. Common foods that contain probiotics are yogurt and fermented milk drinks. Maintaining a balance of healthy bacteria in the intestine is beneficial for a healthy digestive system.

Protein is an essential nutrient that is used in the body for the growth and repair of cells and to provide energy. Protein is found in both plant and animal foods. Sources of protein include meat, eggs, dairy foods, nuts and seeds, dried beans and lentils.

Recommended dietary intakes are the daily dietary intake levels for certain nutrients and are determined for different age and gender groups. The RDI is designed to be sufficient to meet the nutrient requirements of nearly all healthy people. RDI’s in Australia are developed by the National Health and Medical Research Council.

Resistant starch is a type of starch that is fermented by the bacteria in the large intestine. This fermentation has a similar effect to dietary fibre, helping to keep the bowel healthy. Legumes, intact whole grains, some breads and cereals and under-ripe bananas are all sources of resistant starch.

Saccharide is technical term used to describe sugars. Chains of sugars, or saccharides, make up carbohydrates. Monosaccharides is a chain of one sugar; disaccharides are a chain of two sugars and polysaccharides are a chain of many sugars.

Satiety is the physiological feeling of satisfaction or fullness after a meal.

Saturated fat is commonly referred to as ‘bad fat’ because of its impact on blood cholesterol levels. Saturated fats are often solid at room temperature and are the type of fat predominantly found in meat and dairy foods but also in vegetable sources such as palm and coconut oil.

Sodium is a mineral that is a component of salt. While our body requires a certain amount of sodium to maintain proper functioning, too much has been associated with increased blood pressure in some people.

Soluble fibre is a type of dietary fibre that is thought to help in lowering cholesterol levels. Beta-glucan is a type of soluble fibre found in high amounts in oats and barley. Fruit and vegetables, dried beans and lentils are other sources of soluble fibre.

Star Choice Registered Products are products that meet nutrient criteria set out by the Western Australia School Canteen Association and the Federation of Canteens in Schools and are approved for sale in accredited canteens. Nutrient criteria set limits for levels of fat, salt, fibre and sugar in foods as well as selected nutrients such as calcium in some categories.

Sugar alcohols are sugars that have an alcohol chemical group attached to them. Isomalt, sorbitol, lactitol, maltitol, mannitol, xylitol and erythritol are all sugar alcohols. They occur naturally in some fruits & vegetables but most are man-made. Sugar alcohols provide less energy than regular sugar and are commonly used in ‘sugar-free’ foods like hard lollies, chewing gum and throat lozenges. Because sugar alcohols are not broken down by the body, excessive consumption of foods containing sugar alcohols can cause a laxative effect.

Also known as saccharides, sugars are the smallest form of carbohydrates. When we digest carbohydrate containing foods they are broken down into single sugars for absorption into the blood. Naturally occurring sugars include fructose (mostly found in fruits) and lactose in milk. Glucose is naturally present in some fruits and honey and sucrose is found in sugar cane and sugar beet. Cakes, biscuits and soft drinks contain added sugars.

There are two source of trans fat. Firstly, trans fat is found naturally, in small amounts, in some animal foods, such as beef and dairy. The second source of trans fat is created when liquid vegetable oils go through a process called partial hydrogenation, which is used to improve the stability of oils. Partially hydrogenated vegetable fats are used by food manufacturers because they allow longer shelf-life and give food desirable taste, shape and texture. Commercially produced trans fat are found in margarine, biscuits, crackers, fried foods, pastries, baked goods, and other processed foods made with partially hydrogenated oils.

Trans fat occurs naturally in low levels in some animal foods such as dairy products. Commercially baked or fried foods can be a major source of trans fat, depending on the type of fat used in their manufacture. Trans fats are unsaturated fats that have had their structure changed through the process of hydrogenation and, like saturated fats, are considered a ‘bad’ type of fat as they have been shown to raise blood cholesterol levels.

Vegetarian refers to a diet that is predominantly based on plant foods. There are different types of vegetarian diets in which different levels of animal foods may be included. For example, a vegan diet contains no foods of animal origin, lacto-vegetarians include dairy products and ovo-lacto-vegetarians include dairy products and eggs.

Vitamin A is found in animal foods including liver, dairy products, egg yolk and some fatty fish. Orange and yellow coloured fruit and vegetables (e.g. mangoes, carrots) contain carotenoids such as beta-carotene which are converted into vitamin A in the body. Vitamin A plays an important role in vision and growth and beta-carotene acts as an antioxidant to help protect against free radical damage.

The B group vitamins (B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6, B12, folate and biotin) are found in meat, poultry, wholegrain products, dairy products, eggs, green leafy vegetables, nuts and seeds. Their main role in the body is in energy metabolism.

Vitamin C plays a role in ensuring healthy connective tissue such as skin and cartilage. Vitamin C is also an antioxidant and can be found in a wide range of fruit and vegetables.

The main role of Vitamin E in the body is as an antioxidant. Vitamin E protects many substances from oxidation but is particularly important for maintaining the stability of cell membranes by protecting them from free radical damage. Good sources of vitamin E include almonds, peanuts and soy bean oil.

Vitamins are essential micronutrients that are used in the body for a variety of processes. They are classified into two groups - fat soluble and water soluble. The fat soluble vitamins are vitamins A, D, E and K. The B group vitamins (B1, B2, B3, B12), folate, biotin and vitamin C are water soluble vitamins.

Wholegrains are seeds of plants like wheat, rye, corn, barley, rice and oats that store the nutrients plants need to reproduce. Wholegrain foods contain the three natural components of the grain kernel -the bran (outer layer), germ (middle layer) and the endosperm (inner layer).

Zinc is a mineral that plays a part in many functions in the body including wound healing and can be found in oysters, beef and wholegrain breads and cereals.