Acupuncture: Inserting needles into the skin at certain points for therapeutic or preventative purposes.

Amino acids: The building blocks of protein.

Anemia: Having a low level of red blood cells in the blood.

Anorexia: An eating disorder where body weight is below a healthy weight for a person’s height. It can cause health problems and even be fatal.

Anthropometric: Related to measurement of the human body’s physical characteristics, such as weight and height.

Antibiotics: Drugs used to treat or prevent some bacterial infections.

Antioxidants: These are chemical substances that inhibit oxidation, such as vitamin A, vitamin C and vitamin E.


Bacteria: Tiny single-cell microorganisms found everywhere, some of which are infectious and cause disease.

BCA (Body Composition Analysis): Measurements to determine body fat percentage and lean body mass.

Behavioural guidance: Providing nutritional counselling and advice to help people learn proper healthy eating habits.

Behavioural modification: Changing a person’s behaviour through the manipulation of signals and environmental factors which trigger certain behaviours.

Blood pressure: The pressure exerted by blood on the walls of the blood vessels (i.e. the arteries).

Blood glucose: Also known as blood sugar, this refers to the amount of glucose (sugar) present in a person’s blood.

BMI (Body Mass Index): BMI is a measure of a person’s weight relative to their height. The score is analysed against a chart to see if the person is underweight, a healthy weight, overweight or obese.

BMR (Basal Metabolic Rate): BMR is the rate of energy used for metabolism when the body is resting. It is essentially the amount of calories you would burn in 24 hours if you did not move at all.

Bulimia: Uncontrolled periods of binge eating, followed by self-induced vomiting.


Caffeine: A natural stimulant which is frequently found in food and drinks, such as coffee and tea.

Calcium: An essential mineral that helps the body form strong bones and teeth.

Calorie: A unit of measurement for food energy.

Cancer: An abnormal and uncontrollable growth of cells.

Carbohydrate: One of the three main macronutrients used by the body for energy, carbohydrates are made up of carbon, hydrogen and oxygen. Sugars and starches are carbs.

Cardiovascular disease: A disease affecting the heart and/or blood vessels.

Cholesterol: This fatty substance is found in the body, and is known as a lipid. Cholesterol is vital for the body to function normally, and combines with fatty acids in the blood stream to form Low-Density (LDL) and High-Density (HDL) lipoproteins. LDL cholesterol is referred to as ‘bad cholesterol’ because having too much of it is unhealthy.

Complete protein: A protein which contains all of the essential amino acids.

Constipation: Experiencing difficulty passing feces.


Diet: The kinds of food that someone eats habitually. The term can also be used to refer to a specific course of food which is followed in order to lose weight.

Dietary assessment: An analysis of the nutrients present in a diet.

Diarrhoea: Passing feces more frequently than usual, and in liquid form.

Dysmorphia: An anxiety disorder that causes someone to have a distorted view of their body, e.g. believing their body is fatter or thinner than it actually is.


Eating disorder: A behavioural disorder that involves any of: avoiding food consumption, excessive food consumption, self-induced vomiting and other similar actions.

Electrolyte: Elements which are essential for normal cell function and the regulated distribution of body fluids such as sodium and potassium.

Elimination diet: A diet where certain foods are removed from the diet and the effects on the body are observed.

Enzyme: A complex protein responsible for chemical reactions in a cell.

Essential amino acids: Amino acids that the body cannot synthesise, but which are important to human nutrition and must therefore be supplied through the diet.

Essential fatty acids: Fatty acids that the body cannot synthesise, but which are important to human nutrition and must therefore be supplied through the diet.


Fast food: The term given for mass-produced food which is prepared and served very quickly. Often less nutritious than other foods.

Fat: One of the three main macronutrients used by the body for energy. Fat is rich in carbon and hydrogen.

Fatty acids: A component of fats.

Fibre: This is the term given to the indigestible parts of fruit and vegetables. Fibre is highly important in the body’s digestive process, providing bulk.

Fructose: A naturally occurring sugar.

Functional food: When a certain additional function is given to a food, such as calcium being added to orange juice, to provide a health benefit.


Glucose: A simple sugar that is the main source of energy for living cells. All three macronutrients lead to glucose production but carbohydrates produce the most.

Gluten: The term for a mixture of proteins found in wheat.

Glycemic Index (GI): A dietary index to tell us whether a certain carbohydrate-based food raises blood glucose levels slowly, moderately or quickly when eaten on its own.

Glycemic Load (GL): This takes portion size into account, multiplying the number of grams of carbohydrate present in a serving of food by the Glycemic Index for that food, and then dividing by 100.


HDL: High Density Lipoprotein, referred to as being ‘good cholesterol’.

Heart: The muscle that pumps blood throughout the body.

Heart attack: Occurs when the flow of blood to the heart is blocked, often due to a blockage in a coronary artery. May result in the death of heart muscle and can be fatal.

Heart disease: The term for any disorder affecting the heart, such as arrhythmia, heart attack and coronary artery disease (CAD).

Hemoglobin: A protein molecule containing iron which is found in red blood cells. It is responsible for transporting oxygen from the lungs to the body tissues.

High quality protein: An easily digestible and complete protein.

Hypertension: Also known as high blood pressure, this is when the long-term force of blood against artery walls is too high that it might cause health problems such as heart attacks, because your heart and blood vessels are under extra strain.

Hydration: The process of replacing water in the body, to avoid dehydration.

Hypercholesterolemia: Also known as dyslipidemia, this condition is characterised by the presence of high levels of cholesterol in the blood.

Hyperglycemia: High blood glucose levels.

Hypoglycemia: Low blood glucose levels.

Hypotension: Also known as low blood pressure, this is when the pressure exerted by blood against artery walls is abnormally low. Symptoms can include dizziness and fainting.


Immune system: The organs and processes of the body which provide protection against infection and toxins.

Indigestion: A reduced ability to digest food properly.

Insulin: A natural hormone secreted by the pancreas. It helps regulate blood glucose levels and promotes the storage of glycogen.

Iron: An essential mineral that is necessary for red blood cell formation. An iron deficiency can lead to fatigue, and may cause anemia.


Joint: The point where two bones are attached for the purpose of allowing body parts to move, often formed of cartilage and fibrous connective tissue.

Junk food: Unhealthy foods which are high in calories but have little nutritional value. Usually quick and easy to prepare and eat.


Ketones: Chemicals produced as a by-product when fat is broken down for energy.

Ketosis: A natural state where the body is almost completely fuelled by fat, rather than glucose. Can occur on a low-carb diet or when fasting, and increased levels of ketones in the blood indicates the state has been reached.

Kwashiorkor: A severe form of malnutrition, where there is a lack of protein in the diet. The condition is usually found in developing countries, and symptoms can include a swollen stomach and hair loss.


Lactic acid: A substance produced in the muscle tissues during exercise, it can cause a burning sensation while the muscles are active.

Lactose: The main carbohydrate in milk. This sugar molecule is made up of glucose and galactose.

Lactose intolerance: A common medical condition where the body is unable to digest lactose, due to a lack of lactase being produced. It can result in diarrhoea, flatulence and abdominal pain.

LDL: Low Density Lipoprotein, referred to as being ‘bad cholesterol’.

Lipids: Substances such as fat, oil and wax, which are insoluble in water.


Macronutrient: A type of food which is required in significant amounts in the diet. The three main macronutrients are carbohydrate, fat and protein. Nutrients are often grouped into being either macronutrients or micronutrients.

Magnesium: An essential mineral, it is involved in many processes occurring in the body.

Malabsorption: When the small intestine is unable to properly absorb important nutrients and fluids. Can be caused by Crohn’s disease, celiac disease, lactose intolerance and other conditions.

Malnutrition:When the body is lacking in sufficient nutrients required to maintain health.

Metabolism: The entire range of biochemical processes occurring within a living organism to maintain life. The term is often used to refer to the process of food being broken down and transformed into energy.

Micronutrient: A type of food which is only required in very small quantities.

Minerals: Inorganic elements, ions or compounds which are required for the body to function normally.

Morbid obesity: Being 100 to 149 per cent above the ideal body weight for your height.


Nausea: An unpleasant feeling in the stomach that occurs before vomiting.

Nutrients: Substances obtained from food which are used to provide the body with energy and the necessary materials to maintain, repair and grow tissue.

Nutrition: Maintaining health through proper eating.

Nutritional deficiency: Lacking adequate levels of nutrients in the diet.


Obesity: A chronic disease where a person has excessively high body fat levels for their height, age and gender.

Omega-3 fatty acids: Essential fatty acids that lower cholesterol and LDL levels in the blood. These polyunsaturated fatty acids are found in fish oils.

Osteoarthritis: Inflammation of the joints.

Overweight: When a person weighs more than the accepted norm for their height, age and gender.


Phosphorus: An essential mineral which is a major component of bones.

Potassium: An essential mineral which helps to regulate muscle and nerve activity, heart function and blood pressure.

Processed food: When food has been deliberately altered from its natural state. If food is frozen, dried, canned, baked or pasteurised, it is processed.

Protein: One of the three main macronutrients used by the body for energy, proteins are composed of amino acids that perform vital functions in cells.


Recommended Daily Allowance (RDA): Also referred to as Recommended Dietary Allowance, it provides estimated amounts of nutrients that it is necessary to consume on a daily basis for good health.

Rickets: A disease affecting children which is caused by a deficiency of vitamin D. If a child’s bones soften and become distorted, it could be a sign of rickets.


Satiety: The feeling of satisfaction after consuming food (i.e. feeling ‘full’).

Saturated fat: Fat that only contains saturated fatty acids, and is solid at room temperature. It is harder to break down than unsaturated fat, and consuming high amounts can increase cholesterol levels and therefore the risk of heart disease.

Scurvy: A disorder caused by a deficiency of vitamin C. Characteristics include weakness, anemia and soft/bleeding gums.

Sedentary: Not being active. A sedentary lifestyle increases your risk of becoming overweight or obese and developing a range of health problems.

Sodium: An essential mineral which is important in the distribution of fluids, keeping nerves functioning and maintaining blood volume. Too much sodium can cause high blood pressure.

Stroke: Sudden death of brain cells caused by a lack of oxygen, as a result of blood flow being blocked or an artery to the brain being ruptured.


Trans fat: Also known as trans fatty acid, this is produced through the hydrogenation of oils. Considered the worst kind of fats, trans fat should be restricted or absent from the diet because it increases LDL (‘bad cholesterol’) levels, raising the risk of heart disease.

Type 1 diabetes: An autoimmune disease where the pancreas fails to produce a hormone called insulin. People with type 1 diabetes are insulin-dependent.

Type 2 diabetes: A metabolic disorder where the body produces insulin but it is either not enough, or the body demonstrates insulin resistance, rendering the insulin ineffective. People with type 2 diabetes are mostly treated with diet and/or medication.

Triglycerides: The major form of fat that is stored by the body.


Unsaturated fat: Considered to be a healthier inclusion in the diet than saturated fat, as it generally does not increase LDL (‘bad cholesterol’) levels. Unsaturated fat is a liquid at room temperature. When at least one double bond is present within a fatty acid chain, it is an unsaturated fat. If there are multiple double bonds, it is polyunsaturated, but if there is only one it is monounsaturated.


Vegan: Seen as a more extreme vegetarian diet. Those following it do not use or eat any animal products, such as meat, fish, cheese, eggs and milk.

Vegetarian: A plant-based diet. Those following it generally consume grains, legumes, pulses, nuts, fruits, vegetables, seeds, algae, fungi and yeast. Depending on each individual, dairy products and eggs may also be consumed, but meat and fish are avoided.

Vitamins: Organic nutrients essential to good health. Your body needs a range of vitamins to fight off diseases and keep your body functioning normally. There are 13 essential vitamins, which cannot be produced by the body and must therefore be included in the diet.


Weight loss: A decrease in body weight, as a result of dieting, exercise, illness, or surgery.

Whole foods: Natural food which is either unprocessed and unrefined, or minimally processed and refined. Examples include whole grains, fruit, vegetables and legumes.


Yeast: A type of fungus used to make bread rise. Some people are allergic to yeasts used in baking or brewing.

Yo-yo dieting: The term used when a person goes through a repeating cycle of losing weight, then gaining weight, then losing weight, then gaining weight, and so on.


Zinc: An essential mineral that performs a range of functions in the body. It is a component of hundreds of enzymes.