Monday, October 8, 2012
Carbohydrates – the good, the bad and the ugly
To classify carbohydrates into goodies and baddies, we are going to use the glycaemic index.
Really, no carbohydrate is really good or bad, they are just better for different purposes.
The glycaemic index ranks foods on a scale from 1-100, based on the immediate effects they have on blood sugar levels. Basically, carbohydrate foods that break down quickly during digestion have the highest GI factors. Their blood sugar response is fast and high. Carbohydrates that break down slowly, releasing glucose gradually into the blood stream have low GI factors.
Low GI foods are the best for most people and low GI diets have been shown to have numerous health benefits. A fabulous website explaining the GI in more detail is:
Hi GI foods are beneficial for people such as athletes, where a high, sudden, readily available store of energy is required, such as before or during endurance exercise, or after exercise to quickly refuel glycogen stores. For the general population, however, they should be regarded as "sometimes" foods.
You may have heard of the Glycaemic Load (GL). This measurement is a modification of the GI that takes into account both the quality (GI) and quantity of carbohydrate in a food. This is the best guide to blood sugar response from certain carbohydrates, though it is less often reported.
Influences of food GI
· Degree of processing/cooking – for example, a hot potato has a higher GI than a cold potato, due to cell breakdown when the potato is hot and subsequent reformation when it is cold. In the case of grains, if their fibrous coat is intact, this coat acts as a physical barrier and slows digestion.
· Presence and interactions of other food types eg. Protein or fat can slow the blood glucose response.
· Food absorption blockage.
Some low glycaemic foods – CHOOSE THESE MOST OFTEN
· Apples, pears, grapefruits, peaches, plums, oranges, cherries, firm bananas.
· Sweet potato, sweet corn.
· All bran, rolled oats, barley bran, rice bran.
· Pumpernickel, rye, mixed grain bread and crispbreads, oat-based breads and fruit loaf.
· Spaghetti, pasta, basmati rice.
· Lentils, kidney beans, chick peas, butter beans, haricot beans, black-eye peas, baked beans.
· Milk, yoghurt, custard, low fat ice cream, chocolate.
Some moderate glycaemic index foods – CHOOSE THESE SOMETIMES
· Crumpets, pita bread, arrowroot biscuits, Ryvita, Vita Brits, one minute oats, mini wheats, Nutrigrain.
· Ripe bananas, mangoes, pineapples, sultanas, orange juice, beetroot, broad beans, new potatoes.
· Cous cous, taco shells, pastry.
· Regular ice cream.
High glycaemic foods – AVOID THESE
· White bread, wholemeal bread, bagels, scones, pre-split muffins, rice cakes.
· Coco pops, cornflakes, rice bubbles, weet-bix
· White rice, brown rice
· Parsnips, potatoes, watermelon
· Pretzels, morning coffee biscuits, jelly beans
· Glucose, sucrose, sports drinks.
You can search for the glycaemic index of certain foods via this website: http://www.glycemicindex.com/index.php