Article written Aug 2006 by Helga Marin
I’ve lived in Dubai for 3 years and since coming here I gained 10kg. I read connector every month and have found a lot of valuable information there. I keep running across in magazines and books the term Glycaemic index. I’m curious to know more about it and I’m also interested to know how it is important for weight loss. I found different GI lists on the internet but they are very confusing as they give different information. Pls help
Caroline
The answer:
The term Glycaemic index describes the effect of food (especially carbohydrates) on our blood glucose (commonly referred to as blood sugar). The higher the glycemic index, the faster a food is metabolized by the body. If a food is digested and broken down by the body quickly, your blood glucose levels rise rapidly, leading to a quick insulin response, making you feel tired and hungry sooner. Foods with low GI are metabolized slower, meaning they sit in your digestive track longer and are gradually absorbed by the body. This leads to a more gradual blood glucose increase, the insulin response is kept to minimum, keeping your hunger satiated longer and your energy level stable.
It is Insulin that drives metabolism to store the excess food energy for later use and it also suppresses our abilities to burn fat. So besides facilitating fat storage and being therefore one of the major reasons for weight gain, insulin has also negative consequences on our health.
Excessive production of insulin for a longer period of time has proven to:
- Elevate the level of LDL cholesterol in the blood.
- Elevate the level of triglycerides in the blood
- Increase the risk of diabetic 2
Food high in GI not only increases the production of insulin but it also at the same time reduces the production of Glucagons which is a competing metabolic hormone to insulin. If insulin prevails, the fat storing rate is greater than fat burning. If Glucagons prevails, fat burning rate is greater that fat storing.
You can maximize your fat burning by increasing your insulin sensitivity and by keeping your insulin levels low in following way:
- Eat high fibre foods as they increase your insulin sensitivity and are in general low in GI
- Eat foods low in GI
- Include Omega 3 in your diet like fatty fish and flax seed oil
- Eat more carbohydrates during the first half of the day as your muscles are then more sensitive to its effect and you need the energy.
- Eat small amount of carbohydrates after a workout as your muscles absorb and store carbohydrates with minimum assistance of insulin straight after working out.
- Eat enough protein as protein facilitates glucagons release
| Carbohydrates low in GIMost vegetables
Most high fibre foods Wheat bran Most fruits Whole grain products All bran+ Sourdough Fresh foods Raw foods Pasta Brown rice Beans Milk products Ice cream Some high fat foods |
| Carbohydrates high in GI
Foods high in sugar Crackers and sweets Most cereals- cornflakes Foods containing white flour ex white bread Some fruits ex: watermelon, pineapple, banana, grapes and raisins Carrots Instant potatoes/ baked potatoes Canned foods- except for beans and tuna Processed food Fast food Soft drinks Overcooked food |
GI assigns a value to a food based on the average body’s metabolism of a simple carbohydrate: usually table sugar or white bread, assigned a value of 100. All other foods are then ranked according to how 50 grams of it, as compared to how 50 grams of sugar or white bread, affects one’s blood glucose levels after a period of time. A value below 55 would be considered a low GI; a value from 56 to 69 would be a moderate range; anything above 70 is considered to have a high glycaemic index. While such values provide a handy guide, they have not been standardized, so two different charts may show a different GI value for the same food. To keep it simple the two lists below contain foods that are most commonly recognized as having low or high GI value.
Related to GI, glycemic load is a measurement that not only takes into account the glycemic index of a food, but also how much of it is there. Since, no matter what, you still can’t eat heaping portions of any kind of food, glycemic load may be a better dietary tool than GI alone. Glycemic load can be assigned to an entire meal or to the food eaten over an entire day.
“The thinking is, if you have a high glycemic index food, but you have a smaller amount of it, it may have pretty much the same effect of having a low glycemic index food but a larger quantity of it,”
It means that those that want to follow lower glycemic index diet, can do that and still eat some higher glycemic index foods,”. “It’s watching the quantity of them and having them as a smaller portion of what you’re eating that is important.”
And to complicate things more, the variety of a particular food and the way it’s prepared also greatly impact its GI. Depending upon the variety, a potato can have a GI ranging from 55, for a sweet potato, to 110, for a boiled white potato. And the GI of a potato can be decreased, for example, if you prepare the potato the night before and let it sit in the fridge before you eat it, because the starch becomes less digestible.
Also what you combine that particular food with is of even greater importance. It is the combination of the meal rather than the food itself that gives the meal its GI value. So by having small amount of cooked potatoes with some meat, vegetables and a little bit of olive oil you have greatly affected the GI value of the cooked potatoes. The following gives you the guidelines of how you can lower the GI value high GI foods.
- Combine high GI foods with low GI foods
- Combine high GI foods with fibres
- Combine high GI foods with protein
- Combine high GI foods with unsaturated fat
There are many ways to lose weight but only few of those are actually beneficial for your health and even though the low GI diet gives you good guidelines it is far from being the perfect diet. The GI is only one part of the big picture and there are other things to be taken into consideration to obtain better health and an effective weight loss.
For instance the GI diet says nothing about how much or what kind of protein or fat people should consume on these diets. These forms of nutrition have been shown numerous times to have a large influence on body weight and, no matter how meticulous you are about sticking to a low–GI diet, may impede weight loss.
Making matters worse, different people and different eating situations can provoke greatly varying glycaemic responses, that is, how the body responds to the ingestion of carbohydrates.
Somebody with insulin resistance should for instance be careful with the amount of carbohydrates consumed, even the low GI. An active person needs more carbohydrates than a person sitting in front of the computer all day and not to mention that your mental state highly influence the way you digest and burn carbohydrates.
General guidelines how to choose healthy foods:
- Choose food low in sugar
- Choose food that are not refined or processed
- Choose fresh and whole food like whole grain and fresh vegetables and fruits
- Choose high fibre food
- Choose low fat food especially low in saturated fat
- Choose nutritious food
- Choose food Low in additives
Written by:
Helga Marin
Health Mind and Body