Ask the Dietitian: What Are the Lowest Glycemic Grains?

Here’s how grains differ and why knowing which to avoid with type 2 diabetes is important.

With type 2 diabetes, it’s common to hear advice telling you to avoid certain foods to prevent blood sugar spikes. Foods containing carbohydrates, such as grains, are often on lists of foods to avoid.

Even though they raise your blood sugar, carbohydrates are a necessary part of a diabetes diet. They provide your body with energy and also contain important nutrients like fiber, vitamins, and minerals.

I’ll explain the concept of the glycemic index, provide you with a list of low glycemic grains to try, and share which grains you should avoid if you have diabetes.

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What is the glycemic index (GI)?

Understanding a food’s glycemic index (GI) can be beneficial for managing blood sugar levels, especially if you live with type 2 diabetes.

The GI is a ranking system for carbohydrates based on how much they affect your blood sugar. Foods are rated on a scale from 1 to 100.

• Low GI: 55 or less
• Medium GI: 56–69
• High GI: 70 or greater

High GI foods are quickly broken down, leading to fast rises in blood sugar and insulin levels. Low GI foods produce a slower, more gradual rise in blood sugar levels, which can help maintain energy levels and reduce hunger.

Are all grains good for diabetes?

Not all grains are created equal. Some grain products, like white flour, are high GI and can cause your blood sugar to rise quickly if eaten on their own.

While all grains can be incorporated into a balanced diet, choosing lower GI grains may lead to better blood sugar management. Here are some low GI grains that are good for diabetes:

Pearled barley

Pearled barley has a GI of around 25 to 35, making it one of the lowest glycemic grains.

It’s rich in a type of fiber called beta-glucan, which research from 2020 suggests can reduce cholesterol levels and improve heart health. Try adding barley to soups or stews or using it as a base for salads.

Bulgur

Bulgur, a whole grain made from cracked wheat, has a GI of 46. It cooks quickly and has an earthy, nutty flavor. It works well as a salad topping, an ingredient in tabbouleh, or a flavorful side dish.

Quinoa

While technically a seed, quinoa is typically classified and prepared as a whole grain and has a GI of 50.

Quinoa is a complete protein, meaning it contains all nine essential amino acids (the building blocks of protein). It’s a versatile food that can be used in salads, as a side dish, or even prepared as a porridge for breakfast.

Buckwheat

Despite its name, buckwheat is gluten-free and not related to wheat. With a GI of 50, it’s a low glycemic grain.

Buckwheat is also high in fiber and magnesium, which can benefit heart health. It can be used to make pancakes, waffles, porridge, or a side dish.

Basmati rice

The GI of rice varies depending on several factors, such as the type of rice, how it was cooked, and how it was processed. Basmati rice, which has a GI of 52, is a low GI type of rice. It’s a popular side dish for curries but can also be used to make pilaf or stuffed bell peppers.

Whole wheat pasta

Whole wheat pasta, made using whole wheat flour containing all three parts of the wheat grain (bran, germ, and endosperm), has a GI of 55 and just scrapes into the low GI category.

It’s a good protein and fiber source, contributing to its lower GI. How you cook pasta also affects its GI, with pasta cooked al dente (firm) having a lower GI than pasta cooked to a softer texture.

What’s the difference between different types of oats?

Oats are a popular choice for blood sugar management, but 2015 research suggests their GI can vary depending on how they are processed.

Steel-cut oats, the least processed type of oats with a hearty, chewy texture, have a GI of 55, making them a low glycemic grain. Large-flake rolled oats, which have a GI of 53, are also low GI.

In comparison, oats that have been more heavily processed tend to have a higher GI.

Quick-cooking oats have a GI of 71, while instant oats have a GI of 75. While these types of oats can still be part of a diabetes diet, they may cause your blood sugar to rise more quickly than steel-cut or large-flake rolled oats.

In addition to how they were processed, oats can affect your blood sugar differently depending on whether they’re flavored.

Flavored oats (such as maple and brown sugar flavor) have a greater impact on your blood sugar levels than plain oats due to the added sugar. If you want to add sweetness to your oats, consider adding strawberries or blueberries, which are both low GI.

Which grains should I avoid?

While GI is one factor to consider when choosing which grains to include in your diet, it’s not the only one. It’s also important to consider the typical portion size of a particular grain, as this directly impacts the food’s glycemic load.

While GI measures how quickly a food raises blood sugar, glycemic load takes it one step further by considering the amount of carbohydrates in a food.

Depending on the portion size, a grain with low GI could potentially have a high glycemic load due to its carbohydrate content.

For example, while basmati rice has a low GI, it has a high glycemic load. This doesn’t mean you need to avoid all foods with a high load — it’s just a sign that you may need to reduce your portion size to reduce the overall impact on your blood sugar.

Plus, just because a food is low GI doesn’t mean it’s the most nutritious choice.

While pasta made with durum wheat semolina (white flour) has a low GI of 47, it’s lower in nutrients than whole wheat pasta. This is because the outer bran and germ layers are removed during processing. These layers are rich in fiber, vitamins, and minerals, so removing them strips the wheat of much of its nutrition.

Finally, the GI value of foods is calculated based on how your blood sugar would be affected if you ate that food alone. Since grains are typically eaten as part of a meal, it’s important to consider that you can lower the overall GI of a meal by adding a source of protein or fat.

Overall, there are no grains you need to avoid completely on a diabetes diet, but certain grains will be better choices for blood sugar management and overall nutrition.

Generally, choosing whole, minimally processed grains is best since these grains tend to be higher in fiber, vitamins, and minerals.

Takeaway

Understanding the GI is important for managing blood sugar. Low GI grains, such as quinoa, barley, and buckwheat, can help maintain stable blood sugar levels and provide sustained energy throughout the day.

The level of processing a grain has undergone can have a big impact on its GI. For example, steel-cut oats have a low GI, while instant oats have a high GI.

Opting for whole, minimally processed grains is a good blood sugar management strategy. However, this doesn’t mean you can never eat medium or high GI foods. Combining grains with a source of protein or fat can lower the GI of the meal so that you can enjoy higher GI grains with less impact on your blood sugar.