Nutrition glossary
Here's a handy glossary of 80 of those puzzling and frown-inducing nutrition terms you find on food labels, in advertisements and on the web. I've compiled them for my big book The Complete Food and Nutrition Companion to help you understand and grasp nutrition faster with less confusion. I hope these help!
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Acidophilus. A bacteria Lactobacillus acidophilus added to yoghurt to treat constipation and digestive problems. It helps restore the balance of intestinal bacteria disturbed by illness or antibiotics.
Additives. Any substance added to food during its manufacture to improve taste and appearance or extend its shelf life. Includes preservatives, emulsifiers, antioxidants, colours, flavours and vegetable gums. Additives are listed on the ingredient list specified by their full chemical name or code number. Learn more about additives here.
Alcohol. Ethanol or ethyl alcohol. More than two drinks a day (for men and women) is considered harmful in the long term as excess alcohol contributes to overweight, nutrient deficiencies, cancer and cirrhosis of the liver. Not forgetting car accidents. The alcohol content of beverages ranges from 2-5% for beers, 10-14% for wines and champagnes, 20% for sherries and ports, and 40% for liqueurs and spirits such as whiskey, gin, rum and vodka.
Allergen. A substance that causes allergy. Milk, eggs, soy, shellfish, fish and peanuts are common allergens and have to be highlighted on food labels.
Allergy, food. An abnormal reaction to a particular food or food component. Can show up as anaphylactic reaction (swelling of the mouth and throat), stomach pain, vomiting, diarrhoea, asthma, migraines, hives or rash.
Antioxidants. Compounds that protect the body from damage caused by free radicals, which would otherwise cause ageing and predispose to illness. Examples are beta-carotene, vitamin C, vitamin E, selenium and zinc plus a number of plant compounds such as carotenoids and flavonoids. Read up on antioxidants.
Aspartame. No-kilojoule sweetener ('Equal' and 'Nutrasweet') used in diet soft drinks and chewing gum in place of sugar.
B
Beta-carotene. A form of Vitamin A found in orange-coloured fruits and vegetables. Acts as an antioxidant and is under study at the moment. Read more about this pro-vitamin.
Body Mass Index (BMI). Classification of overweight calculated by dividing your weight (in kilograms) by your height (in metres) squared. The healthy weight range is 20–25. A BMI between 25–30 indicates moderate overweight; over 30, obesity; less than 20, underweight. Find out more about how to assess your weight here.
C
Caffeine. Stimulant found in coffee, energy drinks, cola drinks, tea (green and black) and cocoa. Too much caffeine can be detrimental, causing insomnia, nervousness, upset stomach, frequent urination and irritability. Most people can handle 2 cups percolated or 4 cups instant coffee a day without ill-effect. Read more on caffeine.
Calcium. Essential mineral important for strong bones and teeth. Too little calcium results in rickets in children and osteoporosis in adults. Milk, yoghurt and cheese (both full-cream and skim) are rich sources.
Carbohydrates. Starch, sugars and some components of fibre which are the body’s most important fuel. Sugars are the simplest form of carbohydrate; starches are complex carbohydrates which are broken down to sugars during digestion. Found in plant foods (grains, vegetables, fruit, beans, sugar and honey).
Carotenoids. A group of 500 to 600 naturally-occurring compounds which gives fruit and vegetables their yellow-orange colour and act as anti-oxidants.
Catechins. A group of four related compounds found in both green and black teas which act as antioxidants and are responsible for tea’s unique flavour and aroma.
Cholesterol. Fat-like substance normally present in the blood which has many important roles. High blood cholesterol (over 5.5 millimoles per litre) is one of the risk factors for heart disease. It is made by our livers which accounts for approximately 75 per cent of the total cholesterol circulating in the blood.
Chromium. Essential mineral required for Glucose Tolerance Factor, a compound which improves the action of insulin. Elderly people and adult diabetics have been reported low in chromium. Brewer's yeast, egg yolk, liver, cheese, lean beef and wine are good sources.
D
Dextrose. Alternative name for glucose. Read how glucose compares to other sugars.
Digestion. Mixing and breakdown of food by juices and enzymes from the stomach, pancreas, liver and intestine, to allow absorption of nutrients into the bloodstream. Carbohydrates are converted to glucose and fructose, protein to amino acids, and fat to glycerol and fatty acids.
E
Electrolytes. Minerals in solution — sodium, potassium, calcium, magnesium, chloride, phosphates, sulphates — which control much of the body's biochemistry. Electrolyte balance can be disturbed through extreme fluid loss as in illness, diarrhoea, vomiting and heavy sweating.
Emulsifiers. Compounds such as lecithin, monoglycerides of fatty acids and monostearates which prevent oil and water mixtures from separating. Read more about the 24 approved emulsifiers here.
F
Fats (lipids). Oily or waxy substances made up of fatty acids and glycerol. Generally overconsumed by affluent societies and contribute to overweight, heart disease and certain cancers. Fats are high in kilojoules, supplying 37 per gram. Read more on fats and how much we need here.
Fatty acids. Can be saturated, mono-unsaturated or polyunsaturated, depending upon their chemical structure.
Fibre, dietary (roughage or bulk). Includes cellulose, hemicellulose, lignin, pectin and gums, each of which has a different action in the body. Fibre creates bulky faeces, relieves constipation and can help reduce the incidence of diverticulitis, bowel cancer and haemorrhoids. Some types of fibre delay food absorption and lower cholesterol. Find tips on how to eat to beat constipation here. Or download my Fact Sheet on Fibre here.
Fish oils. Oils extracted from oily fish which are high in omega-3 fats. Find out more here.
Flavonoids. A large group of natural plant compounds under study for their action as antioxidants. They are found in all vegetables and fruit. Richest sources are tea, wine, grapes, apples, onions and berries.
Folate (folic acid). A B vitamin needed for the synthesis of genetic material, red blood cells and protein metabolism. Extra folate is now recommended before conception to prevent neural tube defects such as spina bifida in babies. Read more about this vitamin and where to find it here.
Free radical. Any unstable molecule that reacts with and damages other molecules. Formed in the body and left behind by smog, smoking, pollution and UV radiation.
Fructose. A sugar found in fruit and honey and a constituent of sugar. Read more about how it compares to sugar.
G
Genetically modified foods. Any technique that uses a living organism to modify the genetic makeup of cells so they will produce new substances or perform new functions. Soy, genetically engineered to be resistant to the herbicide Roundup, now makes up about 30 per cent of soy crops in the USA and genetically modified tomatoes, potatoes and corn are on their way. Labelling of genetically modified foods is underway in Australia.
Glucose. A simple sugar which is the building block of starch and a constituent of sugar.
Gluten. A protein in wheat, rye, oats and barley. People suffering from coeliac disease cannot tolerate gluten and must avoid these four grains. Read why a gluten-free diet is not always the answer to better health.
Glycaemic Index (GI). A measure of the effect of a carbohydrate food on blood glucose levels. Values range from 0 to 100 with pasta and legumes being low (slowly-absorbed) and rice and potatoes being high (quickly-absorbed).
H
Histamine. Compound found in wine, beer, chocolate and matured cheese commonly reported as causing migraines.
Homocysteine. A building block of protein and, if elevated, is now regarded as an independent risk factor for heart disease. Is reduced by high intakes of folate and vitamin B12.
Hypoglycaemia. Low level of glucose in the blood due to excess production (or overdose) of the sugar-controlling hormone insulin. Causes trembling, sweating, mental confusion and in diabetics can lead to coma. Claims that widespread hypoglycaemia is caused by processed foods, especially sugar, do not stand up to scientific scrutiny.
I
Iodine. Mineral essential to the thyroid gland. Found in iodised salt, seafood, seaweed and vegetables grown in soils containing iodine. Read up on how bread now must be baked with iodised salt.
Iron. Mineral needed for the red colouring of blood and muscle protein. Although it occurs in many foods, only 10 per cent is absorbed by the body from lean meat and 1–5 per cent from vegetables and grains. Women, adolescents and athletes have higher iron requirements. Read more on iron to overcome tiredness and anaemia here.
Isoflavones. Compounds found in soy beans and other legumes that have oestrogen-like qualities and may relieve the symptoms of the menopause, and help prevent cancer and heart disease.
Isomalt. Sweetener made from sugar but with only half the kilojoules. Used in confectionery. Has a laxative effect in high doses.
K
Kilojoule (kJ). Unit of energy used to measure the energy of food and diets. In the metric system, the kilojoule replaces the Calorie and 1 kilocalorie equals 4.2 kilojoules. Read more on how to quickly convert kilojoules to calories and vice versa.
L
Lactose. Sugar found in milk sugar.
Lipids. General description for fats and oils. See Fats.
Lycopene. An important carotenoid found almost exclusively in tomatoes and tomato products. A powerful antioxidant, several studies have linked lycopene to lower rates of cancer of the prostate, pancreas and stomach. Read up on the lycopene found in tomatoes here.
M
Magnesium. A key mineral in many enzymes, and together with three other minerals, calcium, sodium and potassium, controls muscle contraction and nerve functioning. Magnesium occurs widely in foods.
Monosodium glutamate (MSG). A flavour enhancer (code number 621) used in some Asian restaurants and savoury foods like soup and sauces. Once linked to a reaction called the 'Chinese Restaurant Syndrome', where it was supposed to cause chest pains, facial flushing and headache, MSG has now been cleared. It still poses a problem for glutamate-sensitive asthmatics. Read up on MSG here.
Mono-unsaturated fats. Fats with one double bond in their chemical structure. Found in all fats but high in olive, canola, macadamia and peanut oils and avocados. Mono-fats lower cholesterol and are less susceptible to oxidation than polyunsaturates.
N
Niacin. A B vitamin needed for the release of energy from food, especially carbohydrates. Found in lean meat, especially liver, nuts and pulses.
Nutrients. Key food factors required for health and growth such as protein, carbohydrates, fats, vitamins, minerals and water.
O
Omega 3 fats. Type of polyunsaturated fats which special properties beneficial to the heart and circulation. Also believed to alleviate inflammatory conditions like arthritis and help in learning difficulties. Found in fish and seafood as well as flaxseed and canola oils, green vegetables and walnuts.
P
Pantothenic acid. A B vitamin involved in the release of energy from carbohydrate, protein and fat. Deficiency is rare, as it is found in a wide range of foods.
Para-amino benzoic acid (PABA). A growth factor for bacteria and fungi, but is not essential for humans. PABA occurs in yeast, wheatgerm, vegetables, liver and meat.
Phosphorus. Essential mineral which is needed for bones and teeth. It plays a role in energy reactions and is a component of protein, B group vitamins and genetic material. Phosphorus occurs in most foods.
Phyto-chemicals. Biologically-active substances found in all plant foods (‘phyto’ means plant) which can function as anti-oxidants and help protect against many health problems. Includes the carotenoids, polyphenols, flavonoids, catechins, salicylates, isoflavonoids, lignans, indoles and isothiocyanates, triterpenoids and curcumin.
Phyto-oestrogens. Substances present in plants with a chemical structure remarkably close to that of the human hormone oestrogen. Although not as strong, they are able to mimic the effect of human oestrogen and can help alleviate the symptoms of menopause and protect against heart disease and cancer.
Polyunsaturated fats. Fats with two or more unsaturated chemical bonds in their structure. Two types occur — omega-3 in fish, canola and flaxseed and omega-6 in oils (sunflower, safflower, maize, cottonseed) and polyunsaturated margarines.
Potassium. The predominant mineral in all body cells. Together with sodium, it maintains the electrical differential of the cell membrane and so controls the working of muscles and nerves. Nearly all foods contain potassium Vegetables, nuts, fruit and fruit juices rate highly.
Preservatives. Substances able to slow the spoilage of food. The earliest preservatives were salt, vinegar, saltpetre, alcohol and sugar. Chemical preservatives act in a similar fashion and include sorbic acids, propionic acids, benzoates, sulphur dioxide, nitrates and nitrites.
Pyridoxine. See Vitamin B6.
R
Recommended Daily (or Dietary) Intake (RDI). Daily intakes of essential nutrients considered adequate to meet the needs of practically all healthy people.
Riboflavin. See Vitamin B2
S
Saccharin. Sweetener with no kilojoule value. Discovered in 1879, it is 500 times sweeter than sugar, but can leave a bitter metallic aftertaste. In very high doses, saccharin has caused tumours in the bladders of experimental animals. The equivalent consumption by humans would be higher than is presently consumed. A UK study of diabetics who regularly consumed saccharin over many years reported that they did not suffer any more deaths from bladder cancer than the general population.
Salt. Chemically is sodium chloride. Too much salt is a factor in fluid retention and raised blood pressure, which can cause stroke, heart and kidney disease.
Saturated fat. Type of fat where the fatty acids hold their full complement of hydrogen molecules. Predominates in animal fats (dairy products, meat and eggs) and commercial shortenings used to make cakes, biscuits and confectionery. Coconut and palm oil, although vegetable in origin, are mainly saturated.
Sodium chloride. Salt.
Starch (complex carbohydrate). The storage carbohydrate of plant foods like vegetables, grains, pulses, nuts and fruit. Starches have different structures, which alter their rate of digestion in the human tract.
Sucralose. No-kilojoule sweetener (‘Splenda’) made from sugar but supplying no kilojoules. Has an excellent sugar-like taste and can be used in cooking and baking, unlike other sweeteners.
Sucrose. A double sugar composed of glucose and fructose. Sucrose is found in white and raw sugar, golden syrup, maple syrup, honey and many fruits.
Sugar. Although usually taken to mean white table sugar or sucrose, there are several sugars of nutritional importance — fructose (fruit sugar), glucose, lactose (milk sugar) and maltose. Fructose ranks as the sweetest followed by sucrose, glucose, maltose and lactose. Dietary Guidelines recommend moderation in sugars and sugar-containing foods.
T
Triacylglycerides (triglycerides). Form of fats consisting of glycerol plus three fatty acids. High blood triacylglycerides (over 2 millimoles per litre) is a risk factor for heart disease and stroke.
V
Vitamins. Substances necessary for life which regulate our bodies' metabolism. Except for three, they cannot be synthesised by our bodies so must be obtained from food.
Vitamin A. Occurs as retinol and beta-carotene. Essential for vision, growth and healthy mucous membranes of the mouth, respiratory and urinary tract. Excess intakes of vitamin A are stored in the body and can be harmful.
Vitamin B group. Eight vitamins which function similarly, occur together in cereal grains, vegetables, lean meats and milk and are soluble in water.
Vitamin B1 (Thiamin). Acts to release energy from carbohydrate and maintain the nervous system. In Australia, deficiency occurs largely in alcoholics.
Vitamin B2 (Riboflavin). Required for healthy skin, nails, hair and eyes, it forms part of several enzymes involved in energy metabolism. Read more on riboflavin.
Vitamin B6 (Pyridoxine). Critical for protein and amino acid metabolism. Rarely deficient in normal diets.
Vitamin B12 (Cobalamin). Found only in animal foods and likely to be borderline in long-term, strict vegetarians. Required for the formation of red blood cells — deficiency leads to pernicious anaemia — and utilisation of protein, fat and carbohydrate.
Vitamin C (Ascorbic acid). Essential vitamin which plays a primary role in the formation of collagen, bones, blood vessels and connective tissues. It is required for wound healing and increases the body's absorption of iron. Smokers have an increased requirement for vitamin C. Megadoses of vitamin C have been hailed as a cure for the common cold, but carefully controlled studies have shown it can reduce the severity, but not eliminate colds entirely.
Vitamin D (Cholecalciferol). Formed by the action of sunlight on the skin, vitamin D enables calcium to be absorbed into bones. Cod liver oil, the richest food source, was once given as a regular supplement in northern European countries with their long dark winters, but is unnecessary in Australia.
Vitamin E (Alpha-tocopherol and related substances). Found in vegetable oils, eggs, grains, green vegetables and nuts. Functions as an antioxidant protecting oils from rancidity and is under study for its role in preventing heart disease
Vitamin K. Essential for the production proteins involved in clotting of the blood. Vegetables, eggs and liver are the main dietary sources. Read more about vitamin K here.
W
Water. The most vital of nutrients, around 8 glasses (2 litres) is needed each day, more in hot humid weather or those working in air conditioning. Read more on water here.
X
Xylitol. Sweetener used in combination with other intense sweeteners to produce sugarfree sweets and chewing gum.
Z
Zinc. Essential mineral which forms part of many enzymes in the body, helping metabolise carbohydrate and protein, maintain eyesight and speed healing. Meat, seafood, eggs and milk are excellent sources, with nuts, whole grains and pulses supplying some.
