As a type 1 diabetic, the glycemic index use to be near and dear to my heart, well, that’s until I found out the glycemic load. How do the two differ? Last week I posted about the the glycemic load, but what is the glycemic index and how do they differ? Lets take a closer look!
The Glycemic Index (GI) is a numerical scale used to indicate how fast and how high a particular food can raise our blood glucose (blood sugar) level. A food with a low GI will typically prompt a moderate rise in blood glucose, while a food with a high GI may cause our blood glucose level to increase above the optimal level.
An awareness of foods’ Glycemic Index can help you control your blood sugar levels, and by doing so, may help you prevent heart disease, improve cholesterol levels, prevent insulin resistance and type-2 diabetes, prevent certain cancers, and achieve or maintain a healthy weight. A substantial amount of research suggests a low GI diet provides these significant health benefits. So, it’s worth taking a look at the basic principles of a low GI way of eating.
Why The Glycemic Index Is Important?
Your body performs best when your blood sugar is kept relatively constant. If your blood sugar drops too low, you become lethargic and/or experience increased hunger. And if it goes too high, your brain signals your pancreas to secrete more insulin. Insulin brings your blood sugar back down, but primarily by converting the excess sugar to stored fat. Also, the greater the rate of increase in your blood sugar, the more chance that your body will release an excess amount of insulin, and drive your blood sugar back down too low.
Therefore, when you eat foods that cause a large and rapid glycemic response, you may feel an initial elevation in energy and mood as your blood sugar rises, but this is followed by a cycle of increased fat storage, lethargy, and more hunger! Although increased fat storage may sound bad enough, individuals with diabetes (diabetes mellitus, types 1 and 2) have an even worse problem. Their bodies inability to secrete or process insulin causes their blood sugar to rise too high, leading to a host of additional medical problems.
The theory behind the Glycemic Index is simply to minimize insulin-related problems by identifying and avoiding foods that have the greatest effect on your blood sugar.
High Glycemic Index Foods And Health Problems:
What researchers have learned is that high glycemic index foods generally make blood sugar levels higher. In addition, people who eat a lot of high glycemic index foods tend to have greater levels of body fat, as measured by the body mass index (BMI). High BMIs are linked to obesity, heart disease, and diabetes.
High glycemic index foods include many carbohydrates such as:
- White bread
- Low-fiber cereals
- Baked goods
What Effects The Glycemic Index Of A Food:
Fat and fiber tend to lower the glycemic index of a food. As a general rule, the more cooked or processed a food, the higher the glycemic index; however, this is not always true.
Below are a few specific examples of other factors that can affect the glycemic index of a food:
- Ripeness and storage time – the more ripe a fruit or vegetable is, the higher the glycemic index
- Processing – juice has a much higher glycemic index than whole fruit; mashed potato has a higher GI than a whole baked potato, stone ground whole wheat bread has a lower glycemic index than whole wheat bread.
- Cooking method: how long a food is cooked (al dente pasta has a lower glycemic index than soft-cooked pasta)
- Variety: converted long-grain white rice has a lower glycemic index than brown rice but short-grain white rice has a higher glycemic index than brown rice.
Other items to consider while using the Glycemic Index:
- The glycemic index value represents the type of carbohydrate in a food but says
nothing about the amount of carbohydrate typically eaten. Portion sizes are still relevant for managing blood glucose and for losing or maintaining weight.
- The glycemic index of a food is different when eaten alone than it is when combined with other foods. When eating a high glycemic index food, you can combine it with other low glycemic index foods to balance out the effect on blood glucose levels.
- Many nutritious foods have a higher GI than foods with little nutritional value. For example, oatmeal has a higher glycemic index than chocolate. Use of the glycemic index needs to be balanced with basic nutrition principles of variety for healthful foods and moderation of foods with few nutrients.
The usefulness of the glycemic index is best demonstrated by people dealing with diabetes and are willing to base their diets on the right food, thus minimizing the risks of spikes or high glucose blood levels.
Glycemic Index Accuracy?
So how accurate is the glycemic index? Although its a great tool, there are some concerns when it comes to using the GI and here’s why.
- The tests are performed when the participant is fasted, meaning the affect of other foods are not taken into account.
- Blood glucose is only measured 2 hours post food consumption, not long enough given digestion can last over 24 hours.
- The testing method only tells us how fast a carbohydrate is turned into glucose, not how much is turned into glucose.
- Foods tested at different stages tend to have different GI scores. The sugars in fruit crystallize during the ripening process which can skew the numbers. For example a yellow banana has a higher GI than a freshly-yellow banana, but the GI testing is unable to take this into account.
- As individuals, we metabolize and digest carbohydrates at different rates, meaning even with group testing the glycemic index is not specific to the individual, in turn accuracy is compromised.
- Different carbohydrates are metabolized by the human body in varying ways. For example, some people react well with vegetables but maybe not so much to grains.
So these are some key points to take into account when using the glycemic index. If your looking for a more accurate way to measure you blood sugars, check out my post on the glycemic load.
If this article on the glycemic index was helpful, please leave a comment right below my bio or hit the share button to share with your friends 😀
Thanks for Reading!