GI Explained
Whenever you eat carbohydrate, your body breaks it down into glucose, which can then be used to provide energy for the body. As the carbohydrate is broken down, the level in your blood rises. GI, is a measure of the rate at which the blood rises. High GI foods cause a rapid rise in blood glucose levels, usually followed by a rapid drop; whereas low GI foods provide a smaller, sustained rise in blood glucose levels. In the GI index, each food is given a number according to the rate at which they cause blood glucose levels to rise. If they cause a rapid rise then the food is given a high number. 100 is the highest.
High GI foods cause a high release of the hormone insulin. This causes blood glucose levels to drop quickly (shortly after the rise), which makes you feel hungry and tired. Many low GI foods are bulky because of the water and fibre that they contain, so they are more likely to fill you up without having to consume a large amount of calories. Studies have shown that people who eat low GI meals tend to eat less at subsequent meals.
Choosing low GI foods can reduce or even prevent diabetes, obesity and coronary heart disease. Lower GI diets have also been associated with improved levels of ‘good cholesterol (HDL).
LOW GI Fooods
- Grainy breads
- Bran based breakfast cereals
- Porridge
- Sweet potatoes
- Brown pasta
- Grains (bulgur wheat, couscous, quinoa)
- Nuts (limit to a handful a day)
- Vegetables (raw or lightly cooked)
- Salad
HIGH GI Foods
- pies
- Sweet pastries
- Sugar Rich Drinks
- Doughnuts
- Croissants
- Shortbread and sweet biscuits
- Mashed potato
- Bagels
- Baguettes
- Sweets
- Sugar rich breakfast cereals
Breakfasts:
Home Made Muesli
2 Brazil Nuts
1 tbsp Sunflower seeds
60g Rolled oats
50g Fresh Raspberries
50g Fresh Blueberries
1 Apple, Unpeeled and Roughly Grated
230ml Skimmed Milk
The night before, roughly chop the brazil nuts and mix in a bowl with the sunflower seeds and oats. Measure the raspberries and blueberries so that they are ready for the next day. The following morning, grate the apple flesh and divide into two breakfast bowls, then add the half the nut and oat mixture and half the berries to each bowl. Add milk to taste.
Chilli Omelette Make an omelette using 2 whole eggs, a little chopped chilli and some chilla flakes, some pepper and a tiny pinch of salt. Serve with 1 slice of multigrain toast.
The Glycemic Load
The glycemic load incorporates the glycemic index and portion size. Small portions of high GI foods have a similar effect on blood sugar as large amounts of lower GI foods. If you think about eating a mars bar. If you eat half, it has the same GI as the whole of the mars bar. However the rise in blood sugar is approximately half of that seen when eating a whole mars bar.
To calculate the GL of a food, take the quantity of carbohydrate in grams, multiply by its GI and divde by 100. e.g. white plain baguette 100g GI = 95 Grams of carbohydrate = 50 50 x 95 = 475 / 100 = 4.75
The concept of glycemic load was developed by scientists to simultaneously describe the quality (glycemic index) and quantity of carbohydrate in a meal or diet. This is a lot more useful when attempting to calculate the blood sugar raising effect of a meal. For example, if you had a bowl of table sugar, simply by adding a handful of porridge oats, the GI would be lower. However the GL would be greater.
