Calculating the Glycemic Index & Load
(GL Calculator)

1. What is the Glycemic Load (GL) and why counting it matters

THE GLYCEMIC LOAD (GL) measures the impact of a particular carbohydrate food (or an entire meal) on a person's blood glucose and insulin levels. The higher the GL, the greater the rise in blood glucose and, consequently, the greater the insuline response.

The Glycemic Load is a comparative measure. This means that the above described effects are measured relative to a reference food, which is typically - and completely arbitrarily - either glucose or white bread.

The 2000KCAL Glycemic Load Calculator and the 2000KCAL web app uses glucose as the reference food for calculating the Glycemic Load. Thus, one unit of the Glycemic Load approximates the effect of eating one gram of glucose (1 GL = 1 g glucose).

Low glycemic diet has been proved to be more conducive to a healthy lifestyle. It lowers the risks of diabetes (insulin resistance), and promotes good body composition. We recommend keeping the Glycemic Load (GL) of individual meals below 25, and ideally below 20 GL units.

IMAGE 1: Counting the GI and GL of a sample breakfast in the 2000KCAL app. Notice in the GI column that orange juice and pumpernickel roll have a similar GI, but the GL impact of the pumpernickel is much greater. The total GL of the breakfast is 29.2, which is on the higher side, and we would generally recommend skipping the orange juice or reducing portion size of the pumpernickel to get the GL under 25.

Counting of the Glycemic Index and Glycemic Load in the 2000KCAL app

2. Difference between the GI and the GL. Definitions.

The relationship between the Glycemic Index (GI) and the Glycemic Load (GL) is the difference between the theoretical and the practical.

Glycemic Index Definition. The Glycemic Index (GI) ranks foods according to how their carbohydrates affect our blood glucose and insulin levels. Foods with a low GI value (55 or less) contain carbohydrates that are more slowly digested, absorbed and metabolized, and cause a lower and slower rise in the blood glucose and insulin levels. And vice versa. This definition is similar to the definition of the Glycemic Load (GL), so where is the difference? The Glycemic Index (GI) is nothing but a simple range of values (0 - 100) assigned to individual foodstuffs - a mere ranking system that tells you nothing about the actual impact of the individual foods on your blood glucose. The reason for this is that the GI does not concerns itself with the total carb content. For instance, the GI is not able to differentiate in the glycemic impact of a high-GI food with a low carb content (such as 1 gram per 100 grams), and a log-GI food with a high carb content.

Glycemic Load Definition. The Glycemic Load, on the other hand, is a practical, dynamic indicator that uses the Glycemic Index ranking and combines it with the total carbohydrate content. Because of this it provides a more accurate picture of the food's (meal's) impact on the blood glucose.

Think of the Glycemic Index (GI) as a scale of units such as an inch, foot, yard, and mile. We know that a yard is longer than a foot and shorter than a mile, but on its own this knowledge serves us very little purpose if we do not have anything to measure. It is only after we apply these units to actual objects that we derive utility from them.

3. Calculating the GL

The Glycemic Load (GL) of a food can be calculated using the following formula: GL = GI x grams of consumed carbs / 100
The Glycemic Load of a compound food (a meal) is the sum total of individual GLs.

4. The GL Calculator

The 2000KCAL Glycemic Load Calculator below is an automated tool that uses the above formula to calculate the glycemic impact of individual foods as well as the total glycemic load of an entire meal. Simply type in the required food in the first column, then fill in its amount in the second column, and watch the calculator do the counting. The values displayed will be the carbohydrate content, the Glycemic Index (GI) and the Glycemic Load (GL) of the selected food. The lowermost row in the table shows the total carbohydrate content and the total Glycemic Load of the entire meal.

NOTE: Only foods containing carbohydrates are included in the Glycemic Load Calculator. If you need to work with more foods (there are thousands of them in our database) you need to register at 2000KCAL

carbohydrate foodstuff g carbs (g) glycemic index (GI) glycemic load (GL)
total: -

5. Data accuracy

The Glycemic Load is not as exact an indicator as is, for instance, your weight in kilograms. Its accuracy is affected by a few factors, particularly the variabilities:

  • in the reactions of different people to the same food
  • in the reactions of the same person to the same type of food over time
  • in the content of carbohydrates in the same type of food
The first two factors compound the inaccuracies of calculating the Glycemic Index (GI), leaving no other option than to obtain it by averaging out the various obtained measurements. The "less-then-precise" Glycemic Index is further relativized by the third factor. Lastly, the Glycemic Index of the same food varies based on how the food is prepared or modified by grinding, milling etc.

This does not mean that the Glycemic Load (GL) has no value. Quite contrary, if you learn to approach it in a smart, critical fashion, it will be one of the most significant tools in your quest for a healthy life and a better looking body. There is sufficient scientific as well as self-reported evidence to corroborate the utility of the Glycemic Load (GL), and the author of this article, skeptical as he may be about the many faux dietary concepts out there, believes that this is for a good reason.

Please register to use the 2000KCAL nutritional tool and learn more about the Glycemic Load (GL).

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