Glycemic Index and Glycemic Load: What You Need to Know

By: Alyssa Paglia RD, LD, CLT and Director of Nutrition at Goode Health

As you plan meals and choose foods to eat throughout the day, you’re often thinking about which foods have more protein, or fewer carbohydrates, or are gluten-free or sugar free. One factor that can potentially play a role in balancing your diet is the glycemic index (GI), a scale created to measure how carbohydrates impact your body’s blood sugar levels, which can affect other areas of your health. Glycemic load (GL) takes this one step further, by including the amount of carbohydrates in the food you may be eating.

As the Director of Nutrition here at Goode Health, I also run a private practice, and I want to share what I do in my own practice, to help explain these terms and how you can use it to make the best food choices for your health goals.

In my practice, I encourage patients to take a balanced approach to their meals by choosing foods with a lower glycemic load, especially for those aiming to manage their blood sugar levels or maintain a steady energy level throughout the day. I recommend prioritizing whole, fiber-rich foods such as non-starchy vegetables, whole grains, and legumes along with lean proteins and healthy fats. It’s important to remember that glycemic index and glycemic load are just tools to help you make informed choices (after all, you are eating food, not numbers!) It's essential to consider your overall dietary pattern and personal health goals when making decisions about what to include in your meals.

What is the glycemic index?

The glycemic index is a scale that measures how quickly individual carbohydrate-containing foods cause blood sugar levels to rise. Foods are ranked on a scale from 0 to 100. Foods with a higher number will cause your blood sugar level to rise more quickly than foods with a lower number.

How is glycemic index measured?

A food’s glycemic index score is determined by measuring the impact that 50 grams of carbohydrate (excluding fiber) has on blood glucose levels over the next 2 hours after consumption.

Foods that are quickly digested and absorbed result in a rapid increase in blood sugar levels — these are assigned a higher number on the GI scale (70-100). Foods that are digested and absorbed more slowly, leading to a gradual and slower rise in blood sugar levels are assigned a low GI number (0-55).

What are some common low-glycemic foods and high-glycemic foods?

Some common low-glycemic foods include:

Fruits such as apples, bananas, berries, pears, grapefruit, cantaloupe and honeydew melon
Non-starchy vegetables
Whole grains such as quinoa, wild rice and wheat bran
Legumes such as lentils and chickpeas
Sugar replacement options like honey or maple syrup

Some common high-glycemic index foods include instant rice, rice cakes, sweet potato, bagels, watermelon, mashed potatoes, cornflakes and potato chips.

Pro Tip: Our Wellness Blend includes various ingredients featuring low-GI levels, packed with micro-nutrients, like chia seeds, brown rice, flaxseeds, peas and others.

Are there any limitations of the glycemic index?

The glycemic index is only applicable when an individual food is eaten on an empty stomach. It does not take meals or food pairings into account. The overall glycemic index of a meal is reduced when a high GI food is paired with fat, fiber and protein. For instance, if jasmine rice is paired with baked fish, steamed vegetables, and a side salad dressed with olive oil and vinegar, the impact on blood sugar levels will be lower compared to consuming jasmine rice alone. Interestingly, food preparation plays a role as fried or boiled foods tend to have lower GI than baked foods.

How is glycemic index different from glycemic load?

The glycemic index does not consider portion sizes, as it is based on a fixed amount of 50 grams of carbohydrates in each food.
Watermelon has a high GI of 72, but a 1-cup serving contains only 11.5 grams of carbohydrates. To reach the 50-gram threshold, you would need to eat nearly 4.5 cups of watermelon. In comparison, consuming just 3 ounces of potato chips would provide you with 50 grams of carbohydrates. Glycemic load is a measure that can provide both the index and amount of glucose in the serving of food eaten.

Is glycemic index misleading?

The glycemic index can be misleading because it doesn’t take the whole picture of nutrition into account. A good example is fructose, which surprisingly has a low GI of 25. Excessive fructose consumption has been linked to negative health effects such as insulin resistance, liver damage, and obesity. Just because a food has a low GI doesn’t automatically mean it is healthy.

What are the benefits of a low-glycemic diet?

Low glycemic diets may offer several health benefits, including improved blood sugar regulation and increased weight loss. Let’s discuss why this is:

Improved blood sugar regulation: Low glycemic foods are digested and absorbed more slowly, leading to a gradual and slower rise in blood sugar levels, or better regulation. Various studies monitoring these aspects have found a low GI diet may directly reduce blood sugar levels and improve blood sugar management.
Increased weight loss: A low-GI diet typically includes carbohydrates of a higher quality, leading to more nutrient-dense foods, much like the ingredients in our Wellness Blend. Pairing this with a lower caloric intake diet has been shown to be more effective at reducing body weight and controlling glucose and insulin metabolism when compared to a high-GI diet.

To learn more about our Wellness Blend, how Goode Health is helping to solve “nutrient hunger” and unlock personalized wellness recommendations based on your needs, take our nutritional quiz, HERE.

NOTE: As is prudent with any new dietary plan, it's best to consult with your healthcare professional to understand the implications unique for you.