A Comprehensive Guide to the Glycemic Index (GI)

glycemic index load guide

The glycemic index isn’t something many people pull up on a regular basis to check whether or not they’re maintaining a healthy diet. Instead, we often head to a calorie tracking app or something similar to see the number of calories consumed or the nutritional value of each ingredient. However, knowing where the food you eat fall on the glycemic index can give you some key insight on how your diet may be affecting your health.  

What is the Glycemic Index?

The easiest way to understand what the glycemic index is to think of it as a ranking system for foods that contain carbohydrates. It is designed to give you information on how quickly your body converts the carbs you consume into glucose and how this process can affect your health. The scale lists items as low, medium of high glycemic on a scale of 1-100. Here is a more detailed look at the three ratings:

  • Low glycemic: 55 or less
  • Medium glycemic: 56-69
  • High glycemic: 70 or above

The higher the number, the quicker the carbohydrate gets turned into sugar. The quicker they turn into sugar, the more likely it is to provide a spike in your blood sugar levels and have a negative effect on your overall health. On the other hand, the lower the number a specific food item has, the less likely it is to affect your blood sugar levels.

Typically, sugary foods or refined carbs have a high glycemic index as they are digested more quickly. Foods high in fat, protein and fiber tend to have a low glycemic index. Foods that don’t contain any carbs, such as meat, poultry, fish nuts, seeds, spices, herbs and oils, aren’t given a glycemic index rating.

Additionally, it’s important to know that there are various factors that can affect the GI rating of food. The cooking method you use, type of sugar it contains, ripeness and the amount of processing can take a low or medium GI item and make it high.  For example:

  • Preparing food with fat, fiber or acid from lemon juice or vinegar can lower the glycemic index.
  • The longer your cook pasta and other starches, the higher the glycemic index rating will be.
  • The GI rating of fruits, such as bananas, can increase as they ripen.
  • Combining high glycemic index foods with lower ones can have a balancing effect.

The Differences Between Glycemic Index and Glycemic Load

The glycemic load is slightly different than the glycemic index, as it takes things one step further by factoring in the amount of carbs the food has per serving. This allows the glycemic load to measure the increase in blood sugar based specifically on how many carbs the food item contains per serving, instead of in a general sense like the glycemic index does. As such, it provides you with a more reliable rating and allows you to determine how long a potential spike in blood sugar will last.

For example, watermelon has a glycemic index rating of 72 – a fairly high number, which tells you that it causes your body’s blood sugar to spike rapidly. However, watermelon is largely made up of water and if we take a look at its glycemic load, it’s only a 4. This is extremely low and much more accurate since the carbohydrate content in watermelon is also very minimal. This also means that the increase in blood sugar level that comes from watermelon will not stay high for long.

Additionally, the glycemic index looks at 50 grams of carbohydrates for each food item. There are many foods where consuming 50 grams of carbs is highly unlikely. So, the glycemic load is great to use in these situations, as it factors in how much of the food you would need to eat to reach that 50-gram mark.

To calculate the glycemic load, you take the food’s GI rating and multiplying it by the grams of carbs per serving, and dividing that by 100. Foods that are between 10 and 20 are considered moderate and will not elevate your blood glucose levels for very long. Foods with a GL higher than 20 will keep your blood sugar levels higher for longer and should be consumed in moderation.

Benefits of Tracking GI and GL Ratings

Using the glycemic index and glycemic load allows you to see how different food items will cause your blood sugar to spike and for how long. By learning this information, you can make better choices about your health moving forward. Ideally, this would be to swap out high GI foods for ones with a lower number. By doing so, you can expect several health benefits, such as:

  • Lower risk of diabetes: By learning how food spikes your glucose levels, you can make healthier choices that can lower your risk of diabetes
  • Improve blood sugar management: Eating a diet with a low GI can reduce blood sugar levels and improve blood sugar management, particularly for those with type 2 diabetes
  • Promoted weight loss: Eating a diet with a low GI is shown to increase weight loss.
  • Decrease cholesterol levels: Consuming foods with a low GI rating can help reduce levels of total and LDL (bad) cholesterol.
  • Lower your risk of heart disease: Reducing your total and “bad” cholesterol levels, you can also reduce your risk of heart disease, as high cholesterol levels are major risk factors.
  • Avoid blood sugar spikes: Aim to eat a diet rich in low GI foods, such as nuts, whole oats, most vegetables and some fruits. You can also add in some medium GI foods, such as rice, whole wheat bread and most fruits to avoid blood sugar spikes.
  • Store less fat: Regular consumption of foods that increase your blood sugar levels quickly causes the body to store more fat. By eating lower GI foods, you can reduce the amount of fat stored, which can help with weight loss.
  • Feel less fatigue: Having rapid blood sugar spikes and declines can cause you to feel fatigued, so by reducing them and bringing in more balance, you can start to feel more alert and energized.
  • Diabetes management: If you have type 2 diabetes, you can use the glycemic index as a tool for managing your diabetes.
  • Disease prevention: Using the GI to eat more low GI food items can reduce your risk for type 2 diabetes, gallbladder disease, breast cancer and coronary heart disease.

How To Eat According to the Glycemic Index

Typically, you want to avoid foods that have a high GI, as it means that it gets converted into glucose quickly, which causes a spike in your blood sugar. But as we saw from the example above, it’s important to always factor in the glycemic load for the most accurate information possible.

As a crash course, some low glycemic food items you’ll want to start adding more of into your diet are:

  • Beans and legumes, such as black eyes peas, butter beans, chickpeas, green beans, kidney beans, pinto beans, lentils, lima beans, navy beans, snow peas and hummus
  • Breakfast cereals, such as All Bran, Fiber One, Oatmeal (not instant), and Oat Bran
  • Fruits (1 – 2 a day), such as apples, apricots, blueberries, blackberries, cherries, cranberries, grapefruit, peaches, plums, prunes, pears, raspberries, strawberries, and tangerines
  • Grains, such as barley, bulgur, rye, wild rice, wheat tortilla and wheat pasta
  • Non-starchy vegetables, such as asparagus, artichoke, avocado, broccoli, cabbage, cauliflower, celery, cucumber, eggplant, leafy greens, mushrooms, pepper, tomato, onions, spinach, summer squash, zucchini and turnips
  • Dairy, fish, soy, meat and eggs, such as skim milk, almond milk, soy milk, low-fat or greek yogurt, low-fat cheese, lean red meat, fish, skinless chicken, skinless turkey, shellfish, egg yolks, egg whites, and soy products
  • Nuts, seeds and oils, such as almonds, peanuts, pecans, sunflower seeds, olives, walnuts, hazelnuts and oils at room temperature

You can also want to add in some moderate GI foods, such as:

  • Beans and legumes, such as canned pinto, kidney or navy beans and green peas
  • Breakfast cereals, such as Bran Buds, Special K, Mini Wheats and Swiss Muesli
  • Fruits, such as bananas, grapes, figs, mangos, oranges, raisins and kiwi
  • Grains, such as cornmeal, brown rice, white rice and couscous
  • Vegetables, such as beets, carrots, corn, sweet potato and yam
  • Nuts, such as cashews and macadamia

Maintaining a healthy diet is essential for living a strong and healthy life. One way to do just that is to use the glycemic index as a tool to manage blood sugar and reduce the risks associated with high blood sugar.

Leave a Comment