Difference Between Glycaemic Index and Glycaemic Load
Different foods can cause blood sugar dips or spikes, but tools such as glycaemic index (GI) and glycaemic load (GL) can fill you in on how your body will respond to what you're eating.
Originally, the concepts of GI and GL were developed to determine which foods were best for people with diabetes, but whether you're diabetic or not, these tools are useful for blood sugar management and better diet planning.
What Is Glycaemic Index?
The glycaemic index is a system of classification in which the glycaemic responses of foods are indexed against a standard (white bread). It was introduced in 1981 by David Jenkins, M.D., a scientist at the University of Toronto, to express how much dietary carbohydrates impact blood sugar (glucose) levels.
GI is a numerical way of describing how carbohydrates in foods affect blood sugar levels. The GI ranges from 0 to 100, with pure glucose being given a value of 100.
Processed foods made with refined sugar and flour such as sweets, bread, cake, and cookies have a high GI, while whole foods such as unrefined grains, non-starchy vegetables, and fruits tend to have a lower GI.
GI is categorised as follows:
· Low GI: 55 or less
· Medium GI: 56–69
· High GI: 70 or higher
What Is Glycaemic Load?
The glycaemic load (GL) is a relatively new way to assess the impact of carbohydrate consumption on the rise of blood sugar in the body. It gives a fuller picture than GI alone. GL uses GI and the amount of total carbohydrates per serving of a specific food to estimate both how quickly a food causes blood sugar to rise and how much blood sugar levels will rise in total after eating.
By taking GI and the amount of carbohydrates per serving into account, GL highlights what nutritionists have known for a long time: High or low GI does not necessarily mean healthy or not healthy. Most fruits, for instance, have a high GI, but low GL.
How Glycaemic Load and Glycaemic Index Are Related
Your blood sugar levels are dependent on many factors, including insulin levels, how quickly sugar is absorbed into your bloodstream, and how much sugar (glucose) is in a meal per serving.
GI tells you something about how high your blood sugar could rise with certain foods, but it does not tell you how high your blood sugar will go when you actually eat the food. That’s where glycaemic load comes into play.
GL gives you a more accurate picture of how food impacts your blood sugar levels by considering the following factors:
· The types of sugar and starches in the food
· The way your food is prepared
· Fat content
· Fibre and carbohydrate content
· Serving size
· Rate of absorption and digestion of food products
GL provides food's real-life impact on your blood sugar. Watermelon, for example, has a high glycaemic index (80), but its low carbohydrate content per serving results in a glycaemic load of only 5, (this is because of the high water content found in Watermelon).
How to Calculate Glycaemic Load
GL is a great tool because you don’t need to be a math whiz to calculate it. Dietary GL is calculated by the amount of carbohydrate contained in a specified serving size of the food multiplied by the GI of that food and divided by 100. (Mathematically, GL = GI × available carbohydrate (g) /100)
GL is categorised as follows:
High GL: 20 or higher
Medium GL: 11–19
Low GL:10 or less
Glycaemic Response and Diet
GL and GI estimate the rise of blood glucose in the body after eating a specific food. The lower a food's GI, the slower blood sugar rises after eating that food. In general, foods that are higher in carbs and contain more processed ingredients have a higher GI. On the other hand, foods high in fibre or fat have lower GIs.
GI alone does not tell the full story, because it doesn’t account for the many factors that impact your blood sugar. GL represents the quantity and quality of carbohydrates in the overall diet and their interactions in the body. This is why GL is widely regarded as a more reliable tool than the glycaemic index alone.
Sample Low Glycaemic Load Menu
Glycaemic load offers information about how foods affect blood sugar and insulin. The lower a food's glycaemic index or glycaemic load, the less it affects blood sugar and insulin levels.
Research shows that sticking to a low GL diet can play an important role in staving off type 2 diabetes and heart disease.
Glycemic Load and Disease Prevention
Observational studies have yielded mixed results regarding the association of GI, GL, and adverse medical events.
Studies show that carbohydrates are not bad in and of themselves. Rather, diets that are too high or too low in carbohydrates can be problematic. Eating carbohydrates in the form of whole foods, such as whole grains, legumes, fruits, and vegetables, is better for your health than the carbohydrates contained in ultra-processed foods.
Overall, research shows that eating a low glycaemic load diet, especially one that is high in fibre and whole-grain foods, is considered beneficial for cardiovascular disease prevention and several other chronic diseases, such as type 2 diabetes.
Recap
Glycaemic index explains how carbohydrates may affect blood glucose levels, whereas glycaemic load takes into consideration every component of the food as a whole, giving a more real-life picture of a food’s impact on your blood glucose levels. Both of these tools are valuable in blood sugar management and diet planning.
Extracts taken from Shamard Charles from https://www.verywellhealth.com