What is a Glycemic Index (GI for short)?
Glycemic Index or GI for short is a numerical ranking system used in measuring the comparative degree of absorption and digestion of carbohydrates and their effect on blood glucose. After consumption, a food with a low GI causes a weaker, sustained rise in blood glucose. Foods with a high GI produce a greater temporary spike in blood glucose.
The GI concept was developed in 1980 at the University of Toronto in a study to determine which foods were best for people with diabetes. A lower glycemic response (below 55) usually equates to a lower insulin demand and may improve long-term blood glucose control and blood lipids compared to medium (56-69), or high (greater than 70).
Various situations affect the GI value of a food such as whether it is liquid or solid, the quantity of fiber, and preparation or cooking methods. The GI may also considerably differ between individuals.
Differences or Similarities Between the Low Carbohydrate Diet and the Low GI Diet
The premise behind low carb diets is that the body is forced to use fat as its main source of fuel because throughout the day, blood sugar, (or insulin level) is so low. What occurs with low GI diet plans is similar. The difference lies in low GI diets not restricting carbohydrate intake. It is just restricted in its selection of carbohydrates for consumption.
What is a Glycemic Load?
The concept of glycemic load was developed by scientists to simultaneously describe the quality (GI) and quantity of a carbohydrate in diet. The glycemic load of a food is calculated by multiplying the glycemic index by the amount of carbohydrate in grams provided by a food and dividing the total by 100. For example, the glycemic load of 2.4 ounce French fries with a GI of 54 and 21 g of carbs is GL = 54 x 21g divided by 100 = 11. The GL of a pear with a GI of 25 and 21 grams of carbs is GL = 25 x 21g divided by 100 =5. The French fries have more than 2 times the glycemic weight of a pear.
Five Myths Akin to the GI.
Myth 1 -- Avoid white foods such as potatoes and white bread because they have a high GI.
Color of food does not fundamentally determine a high GI. As referred to above, preparation method, quantity of processing and meal composition influence GI, not food color. For instance, the white bread consumed with 35 grams of olive oil has less GI (20) than white bread consumed with 35 grams butter (78). In this example, eating pasta or white bread in combination with fat and protein at mealtime changes their overall GI values.
Myth 2 -- GI is the best way to establish the quantity of carbs and sugar in certain foods.
Response: GI simply describes the rate by which glucose is released in the bloodstream. In the examples above, both pear and fries have equaled amounts of carb grams but the pear has a lower GL value. On the other hand, one could consume two dissimilar foods with very similar GI values. Foods eaten in higher quantities will produce a higher blood glucose response.
Myth 3 -- Simple sugars are all high in GI.
The GI for most raw fruit is between 30-50 even though they contain the simple sugar fructose (GI 21). Most fruit have a slower rate of absorption and digestion than glucose (GI 93) another simple sugar.
Myth 4 -- GI values can determine healthy and unhealthy foods.
Whole milk, for instance, has a GI of 27 while fat free milk has a GI of 32. The lower GI (whole milk) carries saturated fat and extra calories. Hence, making it a less than healthier choice. Therefore, GI does not discern between healthy and unhealthy foods.
Myth 5 -- I can eat limitless low GI food and still keep my insulin levels low.
Bear in mind that the glycemic response is a combination of GI x carb density. Therefore, higher carbohydrate consumption will still result in higher insulin levels even with low GI values. - 29887
Glycemic Index or GI for short is a numerical ranking system used in measuring the comparative degree of absorption and digestion of carbohydrates and their effect on blood glucose. After consumption, a food with a low GI causes a weaker, sustained rise in blood glucose. Foods with a high GI produce a greater temporary spike in blood glucose.
The GI concept was developed in 1980 at the University of Toronto in a study to determine which foods were best for people with diabetes. A lower glycemic response (below 55) usually equates to a lower insulin demand and may improve long-term blood glucose control and blood lipids compared to medium (56-69), or high (greater than 70).
Various situations affect the GI value of a food such as whether it is liquid or solid, the quantity of fiber, and preparation or cooking methods. The GI may also considerably differ between individuals.
Differences or Similarities Between the Low Carbohydrate Diet and the Low GI Diet
The premise behind low carb diets is that the body is forced to use fat as its main source of fuel because throughout the day, blood sugar, (or insulin level) is so low. What occurs with low GI diet plans is similar. The difference lies in low GI diets not restricting carbohydrate intake. It is just restricted in its selection of carbohydrates for consumption.
What is a Glycemic Load?
The concept of glycemic load was developed by scientists to simultaneously describe the quality (GI) and quantity of a carbohydrate in diet. The glycemic load of a food is calculated by multiplying the glycemic index by the amount of carbohydrate in grams provided by a food and dividing the total by 100. For example, the glycemic load of 2.4 ounce French fries with a GI of 54 and 21 g of carbs is GL = 54 x 21g divided by 100 = 11. The GL of a pear with a GI of 25 and 21 grams of carbs is GL = 25 x 21g divided by 100 =5. The French fries have more than 2 times the glycemic weight of a pear.
Five Myths Akin to the GI.
Myth 1 -- Avoid white foods such as potatoes and white bread because they have a high GI.
Color of food does not fundamentally determine a high GI. As referred to above, preparation method, quantity of processing and meal composition influence GI, not food color. For instance, the white bread consumed with 35 grams of olive oil has less GI (20) than white bread consumed with 35 grams butter (78). In this example, eating pasta or white bread in combination with fat and protein at mealtime changes their overall GI values.
Myth 2 -- GI is the best way to establish the quantity of carbs and sugar in certain foods.
Response: GI simply describes the rate by which glucose is released in the bloodstream. In the examples above, both pear and fries have equaled amounts of carb grams but the pear has a lower GL value. On the other hand, one could consume two dissimilar foods with very similar GI values. Foods eaten in higher quantities will produce a higher blood glucose response.
Myth 3 -- Simple sugars are all high in GI.
The GI for most raw fruit is between 30-50 even though they contain the simple sugar fructose (GI 21). Most fruit have a slower rate of absorption and digestion than glucose (GI 93) another simple sugar.
Myth 4 -- GI values can determine healthy and unhealthy foods.
Whole milk, for instance, has a GI of 27 while fat free milk has a GI of 32. The lower GI (whole milk) carries saturated fat and extra calories. Hence, making it a less than healthier choice. Therefore, GI does not discern between healthy and unhealthy foods.
Myth 5 -- I can eat limitless low GI food and still keep my insulin levels low.
Bear in mind that the glycemic response is a combination of GI x carb density. Therefore, higher carbohydrate consumption will still result in higher insulin levels even with low GI values. - 29887
About the Author:
Rochester Athletic Club, Fitness Center of Rochester and Rochester Weight Loss Programs dedicate its services to helping you get fit and stay healthy.
