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Glycemic Index

Learn about the glycemic index and how it can play a role in healthy weight loss. The articles in this section will teach you the difference between the glycemic index and glycemic load.

Good Carbs vs. Bad Carbs Using the Glycemic Index

From whole grains to sweet treats, carbohydrates impact the body quite differently. Blood sugar also fluctuates with not only carb sources, but with the type and quality of each. The glycemic index can aid in what dictates "good" carbs versus "bad" carbs.


In the scheme of health, "carbohydrate" is a basic word. Carbohydrate sources are vastly different from one another. From whole grains to sweet treats, their impacts on the body are quite diverse. Specifically, blood sugar fluctuates with not only carbohydrate sources, but with the type and quality of each.

Most dietitians and nutrition experts tend to stray away categorizing "good" and "bad" foods and adopt the "all foods fit" approach. However, they also commonly agree there certainly are "better for you" options.

The glycemic index can further aid in what dictates "good" carbs versus "bad" carbs and help weaken carbohydrate misunderstandings.

Carbs & the Glycemic Index

Carbohydrate is one of the three macronutrients, with fat and protein being the other two. Each macronutrient is responsible for supplying the body with energy, also known as calories.

Carbs are considered to be the body's main source of energy and are quickly utilized by the brain and muscles. The ones not used for immediate are stored in the liver or muscles for a later time.

There are two primary types of carbohydrate, including simple and complex carbs:

• Simple Carbohydrates: Simple carbohydrates or sugars either contain one or two sugar molecules. Their short structure causes them to be generally digested and absorbed much more quickly compared to complex carbohydrates.

Not all simple carbs are stripped away from nutrients and fiber, including natural sugars in veggies, fruits, and dairy products. However, most of the intake comes from sources such as corn syrup, table sugar, candy, and soft drinks. These products essentially offer nothing more than sugar and calories.

• Complex Carbohydrates: Complex carbohydrates are also known as starches and polysaccharides, which contain three or more sugars. Their longer structure causes them to be generally digested and absorbed more slowly compared to simple carbs.

Complex carbs are found in fruits, vegetables, legumes and whole grains. They often come in their whole, unprocessed form. Retaining their integrity makes them high in fiber and other essential vitamins and minerals.

What is the Glycemic Index?

The glycemic index (GI) is like a carbohydrate meter, measuring how a carb-containing food impacts and raises blood glucose.

A number scale from 0 to 100 ranks how fast carbohydrate in food turns into sugar in the human body. Pure glucose or sugar has a glycemic index of 100. The index is broken down in low, medium, and high GI's:

• Low GI: Less than 55
• Medium GI: 56 to 69
• High GI: More than 70

The glycemic index is a useful measurement, especially for those living with diabetes, to gauge how food choices influence blood sugars. Equally, though, those seeking weight loss or health can benefit from using the GI.

Lower GI foods are digested slower, keeping hunger at ease and blood sugar levels maintained within a normal level. These foods also typically contain more fiber and nutrients compared to higher GI foods.

The lower the glycemic index, the lower the risk of high blood sugars thanks to their relative slower digestive speed. On the other hand, higher GI foods (think products made with refined sugars and flours) digest rapidly and spike blood glucose.

Foods with a higher glycemic index also tend to be devoid of high nutritional value. This is because they are often stripped down from the fiber, mineral, and vitamin content. Lower glycemic foods tend to supply more nutrients while likewise keeping hunger at ease.

The chart below helps break down "good" versus "bad" carbs based on their GI score and category. Generally, good carbs display a lower GI and bad carbs reveal a higher GI.

*Adapted from a Harvard Health Publication - Glycemic index for 60+ foods

But the utmost importance is to remember glycemic index should not ultimately dictate food choices. For instance, the sweet potato has a higher GI of 70. White rice is comparable. However, sweet potatoes offer a richer nutritional value and offer fiber and essential vitamins and minerals.

Glycemic Index Factors

Though the GI value reflects the carb type, there are additional factors that may reflect blood glucose beyond the specific food.

• Portions: The larger the portion, the higher the glycemic index can rise. Try sticking to recommended portion sizes to reduce unnecessary blood sugar spikes. Additionally, pairing carbs with a protein or fat source can further reduce exaggerated blood sugar levels.

To naturally keep portions and calories in check, fill half the plate with non-starchy veggies. This may include salad greens, roasted cauliflower, steamed broccoli, or a combination of others. A quarter of the plate should feature a lean protein, including chicken, sirloin, or fish. Another quarter should include a whole grain or starchy veggie, such as brown rice or sweet potato. Then complement the meal with a healthy fat source such as olive oil.

• Combination Foods: Stay mindful of combining high carb and glycemic foods and like mentioned above, pair carbs with protein or fat. For instance, salad is known to be a healthy meal option. But adding dried fruits, croutons, and sugar-laden dressings can ultimately increase the total glycemic load.

The glycemic index is based on individual food items, such as an apple or a piece of toast. However, the glycemic load combines both the quantity and quality of carbohydrates. Since most meals and snacks combine multiple different foods, it is useful to refer to the glycemic load with combination foods.

• Cooking and Ripening: The cooking and preparation of foods can have a significant impact on glycemic indexes. Generally, raw foods have a lower GI than in their cooked form. For example, raw carrots have a GI of 20 while cooked carrots have an increased GI of 50.

The ripening process can also influence sugar content. Take, for instance, a banana. As it ripens, it becomes less starchy and apparently more naturally sweet. Sweeter, more ripened fruits are often more readily absorbed. This can cause greater spikes in blood sugar, especially if consumed without a protein or fat source.

Ultimately, consume more wholesome carb sources over processed foods rich in added sugars. Also, pair carb sources with protein and fat to ease the impact of blood sugar spikes and fluctuations.

Trusting in the nation's weight loss meal delivery service can also ensure nutrients are balanced. What's more, meals are also doctor-designed, dietitian-approved, and chef-prepared using fresh, all-natural ingredients. Menus prove to facilitate weight loss and sustain a healthy lifestyle thanks to their lower glycemic load.

In fact, each meal contains 1,100 to 1,400 calories daily. About 40 to 50 percent of total caloric intake from lean, adequate protein. Twenty to 25 percent of calories from healthy fats and 30 to 35 percent from complex carbohydrate. The ratio of nutrients makes meals ideal for minimizing impact to one's blood sugar while providing adequate and balanced nutrients.

Glycemic Index and Diabetes. American Diabetes Association.

Written By Christy Zagarella, MS, RDN. Published on November 07, 2012. Updated on April 10, 2019.


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