If you’re diabetic, prediabetic, or just trying to eat a healthy diet, you’ll want to know about the glycemic load and glycemic index. They make evaluating the impact of foods on your sugar and insulin levels much easier. But to understand how the glycemic load and glycemic index work, it helps to understand more about carbohydrates and how they impact blood sugar. This knowledge will help you make sense of the glycemic load and glycemic index and can lead to you making better decisions regarding food habits and blood sugar tracking.
What Makes Carbs Good or Bad?
Carbohydrates (carbs) are one of the three categories of vital macronutrients, the others being fats and proteins. Carbs are the energy source for our cells, our muscles, and nerves, but we can’t use them until they’re digested.
Carbohydrates are forms of sugars. During digestion, all carbs are broken down into small, simpler sugar molecules—either glucose or fructose—which every cell of the body uses for energy production.
Carbs are either simple or complex, referring to how they’re put together chemically. Simple carbs found in foods like raw sugar or candy need very little digestion and are almost ready to be absorbed and used by the body for energy production as soon as they’re eaten. Complex carbs, like nuts and whole grains, require more time in the digestive tract to be thoroughly broken down into forms that are usable by your body tissue.
It’s the speed at which different kinds of carbs are converted to sugars that affect glycemic load and the glycemic index. Simple sugars flood into the bloodstream, causing blood glucose (blood sugar) to spike.
But this sharp spike of blood sugar will drop rapidly and abruptly, causing the dreaded sugar crash—reactive hypoglycemia.
Complex carbohydrates enter the bloodstream in a trickle, not a flood. They allow blood glucose levels to rise slowly, prompting a gradual and sustainable release of insulin. When functioning properly, our body keeps blood sugar levels and insulin levels balanced. For example, an athlete will consume complex carbohydrates to give their body needed energy over time. If they ate simple carbs, their body would use up all the energy quickly, their blood sugar would dip, and their body could not perform well.
What are the Glycemic Load and Glycemic Index?
Glycemic loads and glycemic indexes are ways to measure how the carbohydrates and sugar in foods will affect your blood sugar levels. Glycemic load is considered more useful than the glycemic index.
The glycemic load is a number that considers several crucial factors about a food, including how fast a particular food’s sugars can enter the bloodstream and how much sugar it has in every serving. Some foods have sugars that may enter the bloodstream rapidly, but per serving, have little sugar at all.
In comparison, the glycemic index (GI) simply indicates how rapidly blood sugar will rise after consuming that food. Lower GI numbers indicate a slow rise of blood sugar; a high GI food’s sugars will enter the bloodstream rapidly.
Importance of Glycemic Load and Glycemic Index
The glycemic load and glycemic index are both useful measurements for anyone who wants to eat a better diet. For healthy people who are not prediabetic or diabetic, the glycemic load rating and the glycemic index provides information that has somewhat less of an immediate relevance than it does for people with prediabetes or diabetes.
However, healthy people who eat a diet filled with high glycemic load foods are at higher risk of developing cardiovascular disease and obesity. Obesity and cardiovascular disease are closely linked to metabolic disorder, which is a primary cause of prediabetes and diabetes.
For people who already have prediabetes or diabetes, glycemic load and glycemic index information can be an important part of staying well. People with these issues need to be aware of how different foods will affect their blood sugar.
Sharp rises in blood sugar and insulin levels contribute to insulin resistance, which over time leads to prediabetes, eventually turning into full-blown type 2 diabetes. Uncontrolled blood sugar levels worsen type 2 diabetes and can lead to many severe outcomes, including kidney failure, wounds that won’t heal, amputations, blindness, and death.
Calculating Glycemic Index
Calculating the glycemic index of a food item is done by professional dieticians or food scientists. To do this, they give people a serving of a food that has 50 grams of carbohydrates. Blood sugar levels are then taken and measured. These results can be found online.
- Low GI foods range from a ranking of 1 to 55.
- Medium GI foods range from 56 to 69.
- High GI foods are those ranked from 70 and above.
Calculating Glycemic Load
Glycemic load is calculated by multiplying a food’s glycemic index by the number of carbohydrates in that food, divided by 100. Some foods, like watermelon, have carbohydrates that rapidly convert to sugar and have a high glycemic index. But that doesn’t tell the whole story because watermelon has relatively few carb calories per serving, so it has a low glycemic load. Because glycemic load includes both how easy the carbs are to break down (glycemic index) and how many carbs are in the food, you get a more accurate measure of the food’s impact on your blood glucose.
What Foods Have a Higher Glycemic Index?
Keeping a healthy eating plan for managing prediabetes and diabetes while balancing a steady metabolism is key to staying healthy. One of the most effective ways of controlling prediabetes and diabetes is to eat a diet that contributes to a steady level of blood glucose. Spikes in blood sugar can lead to uncontrolled rises of insulin, the hormone that allows blood glucose to enter the cells.
The glycemic index of many foods can be found online, but many smartphone apps also contain exhaustive databases. An example is MyFitnessPal (iOS App Store, Google Play). MyFitnessPal contains nutritional information on over 11 million foods, including their glycemic index.
Some other apps provide a food’s glycemic load and glycemic index but don’t provide comprehensive health statistics. However, they do give you a quick way to figure out how rapidly and how powerfully a food is going to affect your blood glucose levels.
Works Cited
- A good guide to good carbs: The glycemic index. Harvard Health. (2021, November 16). Retrieved November 24, 2021, from https://www.health.harvard.edu/healthbeat/a-good-guide-to-good-carbs-the-glycemic-index.
- Barclay, A. (2021, November 1). Gi Group. Glycemic Index – Glycemic Index Research and GI News. Retrieved November 26, 2021, from https://glycemicindex.com/.
- Centers for Disease Control and Prevention. (2020, June 11). Prediabetes - your chance to prevent type 2 diabetes. Centers for Disease Control and Prevention. Retrieved November 25, 2021, from https://www.cdc.gov/diabetes/basics/quick-facts.html
- Cherney, K. (2019, January 23). Sugar crash: Symptoms and treatments for reactive hypoglycemia. Healthline. Retrieved November 25, 2021, from https://www.healthline.com/health/sugar-crash.
- Glycemic index and Glycemic Load. Linus Pauling Institute. (2021, January 1). Retrieved November 24, 2021, from https://lpi.oregonstate.edu/mic/food-beverages/glycemic-index-glycemic-load.
- Group, G. I., & Barclay, A. (2021, November 1). Gi Group. Glycemic Index – Glycemic Index Research and GI News. Retrieved November 26, 2021, from https://glycemicindex.com/.
- The lowdown on glycemic index and Glycemic Load. Harvard Health. (2021, April 14). Retrieved November 24, 2021, from https://www.health.harvard.edu/diseases-and-conditions/the-lowdown-on-glycemic-index-and-glycemic-load.
- U.S. National Library of Medicine. (n.d.). Carbohydrates: Medline plus medical encyclopedia. MedlinePlus. Retrieved November 25, 2021, from https://medlineplus.gov/ency/article/002469.htm.
