When considering various foods that you might wish to add to a diabetes food list, it can be helpful to know their Glycemic Index rating.
The Glycemic Index, or GI for short, is a list of carbohydrate containing foods that have been rated for their speed of conversion to glucose, and the release of that glucose into the bloodstream, compared to a standard reference value of 100 assigned to pure glucose. Pure glucose being very speedily released into the bloodstream since it does not require any further chemical breakdown by the digestive-system as would other food items.
The higher the numerical grading of a food the faster it is absorbed into the bloodstream compared to other foods of lower numerical value. Examples of this would be the breakfast cereals:
All-Bran with an established GI of 42,
Shredded Wheat with a GI of 67, and
Corn flakes with a GI of 84,
indicating that the carbohydrates in Corn flakes are converted much more quickly into glucose than the other two cereals with All-Bran taking the longest time. A faster release of glucose causes a faster and higher spike in blood sugar elevation, something to be avoided, or at least minimized if possible, leading to the conclusion that All-Bran is a better cereal choice than the others to include on the diabetic food list.
But not all high GI foods are bad and there are times, such as before, during, and after exercising, when they are beneficial. The body reacts to the higher blood glucose by releasing insulin, a hormone that assists the body in building muscle, although we must always keep in mind that the diabetic person’s body has an impaired ability to deal with insulin and higher blood glucose. These matters would be better discussed and commented on by the diabetic’s doctor or qualified health team members.
Many foods, such as proteins and fats, do not contain significant amounts of carbohydrate and are not listed on the glycemic Index.
The glycemic index is a useful tool to aid in choosing carbohydrate containing food items to include in a diabetic food list, enabling an emphasis on those with lower index values. But the inclusion of low GI foods in a diabetic food plan is only one of several considerations in determining an appropriate dietary regimen to follow over the long term.
GI range of values
Low GI values are 55 or less
Medium GI values are 56 to 69
High GI values are 70 and above.
The Glycemic Load
But what if the carbohydrate food we eat is only part of a larger meal that is otherwise devoid of carbohydrates, perhaps a meal of mostly protein and fat, of meat, vegetables, fruits, that have little or no carbohydrate content? In that case, measuring by weight in terms of grams, the carbohydrates would be only part of the total grams in the meal and from this an adjusted GI value can be obtained by applying a simple formula..
To cover that situation, there is an extension and enhancement of the glycemic index known as the Glycemic Load. The glycemic load derives a set of values from those of the GI by taking into account the quantity, or quantities, of carbohydrates that are actually in the total meal of food item.
It becomes more practical to consider the GL of a food item when it is only a relatively small portion of the food being consumed, even if it is has a high GI rating,.
For a simplified example: when knowing that one cup of the 84 GI cornflakes weighs about 30 grams, we can easily calculate the proportion of the cornflakes to the weight of the total meal. When being considered as part of a larger breakfast meal of 120 grams weight, it would be 25 percent of the total and that becomes the glycemic load value. 25 percent of the 84 GI is 21, the GL value of the cornflakes in the breakfast.
GL ranges of values
A GL value of 21 is still rather high, the substitution of a lower GI cereal such as Bran flakes or oatmeal porridge would achieve a much lower GI rating. A GL value below 10 is considered to be low and above 20 is high in the opinion of most nutritionists.
An important decision regarding carbohydrate consumption
A major decision rests on what percentage of carbohydrates will be included in the overall diabetic food plan, whether to follow the American Diabetes Association’s recommendations of a high ratio of carbohydrates, or the opposite approach of lower carbohydrates, or somewhere in between. This is a controversial subject for many health care practitioners and needs careful consideration and discussion elsewhere. There are strong advocates whose differing views are worth hearing, even though a diabetic patient mainly depends on his or her personal physician to provide guidance, much of the management of the diabetic condition is in the hands of the individual diabetic.
The food lists available from this blog-site do provide the nutrient content and information for many common food items, indicating whether high or low on the GI and some food groups in general are summarized. For a very complete listing of GI values the following resources are suggested – although doing the research can get rather complicated and time consuming:
1. The University of Sydney, Glycemic Index Web site.
2. David Mendosa, blogger and medical writer.
3. There is also a very good article and explanation by staff of the Linus Pauling Institute at Oregon State University. That explanation references the GI to cardiovascular disease, a major complication of diabetes, and to obesity, to cancer, and to gallbladder disease. With its comments on several other topics of interest, it is worth a read and can be reached at Linus Pauling Institute.
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