Dietitians are often at fault for throwing around nutrition-related words and terms, but do you understand what it means? The Good Life Dietitians bring you a crash course in nutritional lingo.
Antioxidants
An anti-oxidant as the name suggests prevents oxidation of a molecule. This is useful as when a molecule is oxidised it becomes unstable (see free radicals below), which may lead to negative health effects. Antioxidants help to stabilise unstable molecules, much like an unsteady chair with only 3 legs.
Antioxidant is used in the treatment management and prevention of many diseases, such as cancer, heart disease, osteoarthritis, and rheumatoid arthritis. Vitamins A, C and E all act as antioxidants, as well as selenium, phytochemicals and carotenoids, among others. Foods high in antioxidants include blueberries, cranberries, blackberries, Granny Smith apples, red kidney beans, and plums.
BMI
The BMI (body mass index) is a measure of a person’s weight relative to their height, and is calculated as follows: weight/ height2. A person’s BMI gives an indication of whether they fall within a healthy weight range or not. A normal BMI is considered to be between 18.5 and 24.9kg/m2. A BMI below 18.5 is considered to be underweight.
Cholesterol
Cholesterol is a waxy substance that is produced naturally by the liver, and essential for normal functioning of the body. Cholesterol is involved in producing hormones, vitamin D, and is an essential component in keeping cell membranes strong and healthy. There are two types of cholesterol: HDL cholesterol (the good cholesterol) and LDL cholesterol (the bad cholesterol)
However, as a result of eating foods high in fat and cholesterol, cholesterol levels in the blood may increase (called hypercholesterolemia). Although cholesterol is important and necessary for healthy bodies, high levels in the blood can damage the blood vessels which may lead to heart disease, stroke, and even death.
Diabetes
All the foods and liquids we eat turn into glucose (sugar) in the intestines. The glucose moves into the blood, and is then carried into the body cells with the help of insulin, a hormone made by the pancreas. After entering your body cells, the glucose is used to make energy.
When you have diabetes your body either does not make enough insulin or it is not able to use the insulin in makes properly. Because of this, glucose cannot move into your cells and be used as energy.
Empty calories
All foods (apart from water) contain calories (or kilojoules). Empty calories refer to calories in food that are ‘empty’ of nutrients. For example, your favourite chocolate bar is laden with energy but has little nutritional value.
Free radicals
Free radicals are like the bullies on the playground. Free radicals are molecules in the body that bully other stable molecules by stealing their electrons. This in effect makes these molecules unstable, much like a four-legged chair with a broken leg.
Anti-oxidants (see above) protect the body by helping to scavenge these free radicals, and stabilise the unstable molecules.
GI
Lots of attention has been paid in recent years to the glycemic index, shortened to GI. The GI is a measure of the affect that a food has on a person’s blood sugar levels. A low GI food will raise blood sugar levels slowly and steadily, and a high GI food will rapidly increase blood sugar levels.
Dietitians recommended low GI foods over high GI foods as low GI foods keep sugar (and huger) levels more stable. Low GI eating practises are good for everyone, and particularly useful in diabetes and weight loss or weight management.
Heart disease
The term heart disease encompasses a whole range of diseases linked to the heart, such as heart attack (myocardial infarction), coronary heart disease, hypertension, stroke, rheumatic heart disease, and heart failure.
Rates of heart disease are alarmingly high, and are no longer restricted to the older age groups, with more and more young people suffering from heart disease. Risk factors for heart disease include smoking, overweight, a high fat diet, physical inactivity, and stress. Other factors include increasing age and a family history.
Iron
Iron is an essential for the production of haemoglobin (found in red blood cells) and myoglobin (found in muscle cells), molecules that carry oxygen around the body. Iron is also part of many enzymes in the body.
Iron deficiency remains far too common a problem in the 21st century, particularly in young children and women of childbearing age. Good sources of iron include organ meats (liver, kidney, tripe), red meat (beef, lamb, pork, mutton, veal), poultry (chicken, turkey, duck), and fresh or tinned fish. Other sources include dark green leafy vegetables such as spinach, cabbage, and kale, and whole-grain/ whole-wheat foods.
Fruit Juice
The 5-a-day campaign recommends that 2 to 3 servings of fruit are eaten per day, of which a maximum of 1 serving may be in the form of fruit juice. The reason for this is that though fruit is made from fruit juice and thus high in vitamins a minerals, fruit juice is a very concentrated source of energy. Think of it this way: it takes maybe 3 to 4 mangos to produce a glass of mango juice. So in fact in one rather quick drink of mango juice you are actually consuming 3 or 4 whole mangos! Enough reasoning is that the high fibre content of fruit is mostly removed when processed into fruit juice.
Kilojoule
A kilojoule (kJ) is a measure of energy. To get technical, 1kJ is the amount of energy needed to heat 1cm3 of water by 1°C. In South Africa and the UK we use the term kilojoule (kJ) to describe the energy content of food and drinks, and in America and Canada the term calorie (kcal) is used instead. Both kilojoules and calories measure energy, and is very much like the way the British refer to miles and South Africans refer to kilometres. In 1kcal there are 4.2kJ.
Low fat
A product is referred to as low fat when it contains less than 5g of fat per 100g of the product. Next time you chose a low fat product, read the nutrition food label and see if the product complies with this rule.
Macronutrients
Macronutrients are nutrients that are required and consumed in large (macro) amounts: carbohydrates (17kJ per gram), protein (17kJ per gram), and fat (38kJ per gram). Some people refer to alcohol as a fourth food group as alcohol has a unique energy content of
Nutrient-dense foods
A food that is nutrient-dense will contain a higher proportion of nutrients, such as vitamins and minerals, than it contains energy. Nutrient-dense foods include fruits and vegetables as well as whole-grain products.
In contrast, energy-dense foods contain more energy compared to the amount of nutrients. Energy-dense foods are foods like cakes, muffins, pastries, pies, chocolates, among others. Because these foods are higher in kilojoules dietitians advise that you eat less of these foods. Worth a mention is that not all nutrient dense foods are healthy and not all energy dense foods are unhealthy.
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