| The Glycemic Index (GI) is a way of rating | | | | Other factors that can affect a food's glycemic |
| carbohydrate foods according to how quickly the | | | | index, beyond its GI rating, are the amount of |
| carbohydrates are broken down into glucose, and | | | | food eaten. Chocolate has a low GI, but it is 30% |
| thus how quickly that glucose enters the | | | | fat. And any excess nutrients, whether they are |
| bloodstream. The reasoning behind this is that | | | | fat, protein or carbohydrates, will be stored in the |
| carbohydrates that enter the bloodstream quickly | | | | body as fat. So eating too much of low GI foods |
| raise blood sugar levels rapidly, causing a spike in | | | | that are high in calories is not going to help with |
| energy, that is followed by a drop after the | | | | weight loss. |
| effects of insulin are triggered. | | | | Another issue when considering using the GI of |
| Insulin is one of the hormones that help regulate | | | | food, is that the time of day we eat a food may |
| blood sugar levels, and tries to keep them stable. | | | | also impact its effect on blood sugar levels. This is |
| When too much glucose enters the bloodstream | | | | because the GI rating given to a food is based on |
| at a time, the body reacts by releasing insulin to | | | | fasting. So, for example, we fast at night - |
| remove some of that glucose back out of the | | | | meaning we are asleep and thus not eating for a |
| blood and into our cells. Its simply a way of | | | | period of hours. A food thus eaten in the morning |
| keeping the balance. However the effect is that | | | | may more accurately reflect the GI given to it |
| when all the glucose we just ate, in the form of | | | | than at other times of the day, when we haven't |
| carbohydrates, is removed from the bloodstream, | | | | been fasting. |
| we feel tired and hungry, often craving more | | | | Yet the GI does have benefits. One study on |
| carbohydrates. Thus a cycle is created, where we | | | | obese young adults found that a low glycemic |
| eat more than really necessary. | | | | index diet was associated with a reduction in the |
| Carbohydrate containing foods are rated from a | | | | risk factors associated with heart disease, when |
| scale of 1 to 100. A score of 100 is the highest, | | | | compared to similar children with a low fat diet. |
| and this is akin to eating glucose in its pure form. | | | | Both groups lost weight, and kept it off, which is |
| A score of 55 or lower means a food is classified | | | | good news for dieters! And the researchers |
| as having a low glycemic index. Thus, it | | | | suggested that a low glycemic index diet may not |
| theoretically breaks down in the body more | | | | lower metabolism as much compared to low fat |
| slowly. | | | | diets. This is important for dieters as it means |
| I write theoretically, because the picture is a little | | | | they would feel less cold, tired and hungry, and as |
| more complicated than that. For example, fat | | | | a result, would find it easier to stick with the |
| lowers the GI of foods. Potato crisps have a | | | | changes made during the diet period. |
| lower GI than do oven roasted jacket potatoes. | | | | The GI should not be used in isolation. Both |
| However, that does not mean that potato crisps | | | | common sense and other food guidelines, like |
| are a better choice, in terms of nutritional and fat | | | | avoiding excess fat and salt,and making sure |
| content. So, it's important to look at the whole | | | | foods are full of vitamins, minerals and |
| equation when considering meal choices and the | | | | antioxidants, should still be used with the glycemic |
| glycemic index. | | | | index. |
| Some suggestions for using the glycemic index in | | | | References: |
| terms of one's diet is to balance a high glycemic | | | | 1. Australian Healthy Food, November 2005 |
| index food in a meal with a low one. And try to | | | | 2. nutraingredients.com/news/ng.asp?id=66151 |
| make more low or mid range GI choices than | | | | 3. nutraingredients.com/news/ng.asp? |
| high. | | | | |