What Is the Low Glycemic Index Diet?

In a world where a new “trendy diet” or “way of eating” pops up almost every day, it can be confusing to sort through all the noise.

If you’re looking for some guidance on how to incorporate healthy eating into your daily life, you may have considered following a low glycemic index diet.

Centered around how certain foods affect your blood sugar levels using the glycemic index, a low glycemic index diet may be a helpful tool to understand how food impacts your health.

The glycemic index catalogues food based on their amount of carbohydrates and how those carbs react in your body. The scale is 0 to 100. Foods can fall into one of three categories:

• Low glycemic index: 1 to 55
• Medium glycemic index: 56 to 69
• High glycemic index: 70 and higher

But is a low-glycemic index diet the right choice for you?

Registered dietitian Anthony DiMarino, RD, LD, explains how a low glycemic index diet works, its benefits and its potential drawbacks.

What is a low glycemic index diet?

A low glycemic index diet is one based on foods that won’t cause wild swings in your blood sugar.

“Eating foods with a lower glycemic index means they’ll cause a slower and lower rise in your blood sugar,” DiMarino says, noting that this will help you absorb food more slowly and stay full longer and, therefore, eat less. “Foods with a high glycemic index, or simple sugars, give you this quick burst of energy with a rise in blood sugar quickly. But then, you’ll tend to feel pretty tired afterward and will get hungry quickly.”

Certain kinds of foods fall into these categories — for example, foods higher in fat and protein tend to be absorbed more slowly, so they have a lower glycemic index.

Benefits of a low glycemic index diet

Research shows that a low glycemic index diet may come with potential benefits such as:

• Diabetes management. There is increasing evidence that foods with a low glycemic index can reduce your risk of developing Type 2 diabetes. If you already have diabetes, it could potentially reduce the risk of long-term complications.
• Cholesterol management. Studies show that low glycemic foods may be beneficial when it comes to reducing LDL (or “bad”) cholesterol levels. If you have high LDL cholesterol, that increases your risk of heart disease and stroke.
• Weight management. It stands to reason that a diet full of high glycemic index foods would (among other things) up your risk for Type 2 diabetes or insulin resistance. High glycemic index foods can contribute to weight gain, as well as potential complications that go along with that, like stress on your cardiovascular system.

Risks of a low glycemic index diet

There aren’t many downsides to a low glycemic index diet, save for a few exceptions.

For example, if you’re already on insulin and drastically change the way you eat without changing insulin dosages, this could put you at increased risk for low blood sugar. Additionally, if your cholesterol increases after going on a low-carb diet (for example, the keto diet), a low glycemic index diet also might not be the best choice.

Another factor? The glycemic index isn’t necessarily a measure that’s easy to use as a nutrition guide, the way that you can with calories.

And foods with a low glycemic index aren’t necessarily packed with nutrients. Eating a balance of foods from all five food groups — fruits, vegetables, grains, proteins and dairy — is still a better rule to follow.

Low glycemic index foods

Low glycemic index foods are ones with a number that’s 55 or less. Some of these include:

• Vegetables: Peppers, broccoli, tomatoes, lettuce and eggplants
• Fruits: Strawberries, apples, lemons, limes and pears
• Legumes: Chickpeas, beans (dried or boiled) and legumes
• Dairy: Whole/full-fat milk and plain yogurt
• Sweets: Dark chocolate with more than 70% cocoa
• Nuts: Cashews and peanuts

High glycemic index foods — ones that spike your blood sugar quickly — are the usual suspects like pizza, chips, cookies and doughnuts.

Worth noting? Only foods that contain carbs are in the glycemic index of foods database. So, foods such as beef, chicken, fish and eggs won’t be included in the database.

Is it right for you?

While there’s an upside to using the low glycemic index diet as a guide, the American Diabetes Association’s assessment says that the glycemic index numbers are “not easily accessible for meal planning.”

“The best way to use the glycemic index is just as a comparison. If you’re trying to choose between two items, it can help you pick the lower glycemic item over the high glycemic item,” says DiMarino. “You want to eat a well-rounded, healthy diet that is composed of all the food groups.”