How to get started in healthy eating — part 2
Healthy eating terms explained
So often we come across familiar food-related words in the press and other media, but when it comes down to it, do we really know what they mean? Do you know your monounsaturated fats from your polyunsaturated? Your omegas from your antioxidants? Read on and you'll be in the know in no time.
Alcohol — we all know what this is! ‘Alcohol’ is the term used to refer to ethanol and contains a whopping 7 calories per gram!
Amino acids — there are 20 different types of amino acid, eight of which are ‘essential’ — that is, the body cannot make these, so they must be found in the diet.
Antioxidants— these are the good guys, protecting against free radical damage by giving up one of their own electrons, stabilizing the free radical and making it less reactive.
BMI — a mathematical calculation used to determine whether or not a person’s bodyweight is suitably healthy for their height.
BMI = weight in kg/height in m2
A healthy BMI is considered to be between 18.5 and 25. However, BMI can be unreliable because it measures only weight, not fat. Weight in itself is not always a good indicator of a person’s health, for example muscle weighs more than fat, so most athletes are deemed as overweight using the BMI; this does not however mean that they are unhealthy.
Calorie — a measurement of energy. It refers to the amount of energy needed to raise the temperature of 1 gram of water by 1 degree celsius. Food calories are measured by combustion, that is, how much heat is released when a foodstuff burns.
Carbohydrate — compounds of carbon, hydrogen and oxygen. In dietary terms, there are two kinds — complex carbohydrates and sugar. Carbohydrates contain around 4 calories per gram.
Cholesterol — this is an essential fat that your body uses for many biological processes. However, in excess, it can be harmful. It is made mostly in the liver from saturated fat, and circulates in the bloodstream. There is more than one kind of cholesterol.
Complex carbohydrate — this is a term used to describe larger packages (or molecules) of carbohydrate. There are two kinds — starch and fiber. Starch is found in pasta, rice, potatoes and bread and fiber is explained below.
Essential fatty acids — these are fatty acids that the body is incapable of making on its own, and so must take from the diet. There are two — alpha linolenic acid (an omega-3) and linoleic acid (an omega-6) and they are both polyunsaturated.
Fats — fats are made up of fatty acids attached to a glycerol backbone. If there are double bonds between any carbon atoms in a fatty acid, it is said to be unsaturated. Fats and oils are the same, except that oils are liquid at room temperature. Examples include butter, cooking oil, and lard. Many fats are hidden for example, in cream and pastry. Fats are required for padding, insulation, nerve function, production of hormones and transport of vitamins. Fat contains 9 calories per gram.
Fibre — there are two kinds of fiber, soluble and insoluble. Soluble fiber is found in fruits, vegetables, oats and pulses and helps lower cholesterol and balance blood sugar. Insoluble fiber is ‘roughage’ — also found in the above and in bran and other wholegrains. Insoluble fiber aids digestion and can help prevent bowel problems including cancer.
Free radicals — these are extremely reactive atoms or molecules that carry an uncharged electron. They are necessary for a number of biological reactions, but are so reactive they can also cause cell damage. They are implicated in the development of cancer, heart disease and some chronic diseases. Exposure to certain things for example: cigarette smoke, UV light, pollution or radiation can create free radicals.
HDL cholesterol — high density lipoprotein cholesterol. This is carried by proteins called high density lipoproteins and is the ‘good’ cholesterol. HDLs remove cholesterol from the bloodstream and take it back to the liver.
LDL cholesterol — low density lipoprotein cholesterol. This is carried by proteins called low density lipoproteins and is the ‘bad’ cholesterol. LDLs carry cholesterol around the body and deposit it on artery walls. Too much LDL cholesterol can lead to the development of fatty ‘plaques’ which in turn are a risk factor for heart disease. A high intake of saturated fat can lead to an increase in LDL cholesterol.
Minerals — inorganic substances, not all of which are essential to life. Examples of minerals are calcium, iron, zinc, potassium, and sodium.
Monounsaturated fat — an unsaturated fat with one double bond. Olive oil and some nut and seed oils are monounsaturated.
Omega — this is a naming system. It relates to which of the carbon atoms the first double bond occurs, e.g. omega-3, -6 or -9. Omega-3 oils have attracted a lot of attention of late for their protective properties.
Polyunsaturated fat — an unsaturated fat with multiple double bonds. Corn oil, some seed oils and fish oils are polyunsaturated.
Protein — proteins are made up of amino acids and are required for growth and repair. Meat, fish, eggs, dairy products, nuts, pulses and cereals contain protein. Protein contains 4 calories per gram.
Saturated fat — tend to be from animal sources and raise the levels of bad cholesterol.
Sugar — this is a term commonly used to describe ‘simple’ carbohydrates, or those in smaller packages. There are two kinds — intrinsic and extrinsic. Intrinsic sugars are the ones that are incorporated into the cell walls of plants, for example those found in whole fruits and vegetables. Extrinsic sugars are those which are not, for example those in milk, beet sugar and honey. Non-milk extrinsic sugar is what is more commonly known as refined or added sugar.
Trans fat— these are man-made polyunsaturates with an altered structure, and have been linked with ill health, including raised cholesterol.
Unsaturated fats — tend to be from plant sources. These types of fats reduce levels of bad cholesterol in the blood and can raise levels of good cholesterol.
Vitamins — organic (carbon based) substances that our bodies can break down and alter. Vitamins are needed in very small amounts, but are essential to life. There are two kinds: fat soluble (A, D, E and K) and water soluble (the B vitamins and vitamin C). Fat soluble vitamins circulate in the blood and are stored in fatty tissue, so do not need to be eaten every day. Water soluble vitamins circulate freely but are not stored, so you need to eat them more frequently.
So now you know what healthy eating is and understand the terms used by nutrition experts, how do you go about putting that knowledge into practice? What does a day’s healthy eating really look like? Check out How to get started in healthy eating — part 3 to find out how to put your healthy eating knowledge into practice.