Written by Xavier Toledo, BSc Dietetics, Reviewed by Diana Licalzi, MS, RD
Whether you have diabetes or not, there’s a good chance you’ve encountered messaging that demonizes potatoes. Given this, you might be surprised to learn that in their whole form, potatoes are a delicious and nutritious food choice for those with and without type 2 diabetes.
There are many misconceptions regarding the role potatoes can play in a diabetes-friendly diet. The controversy tends to revolve around one factor: their high starch content. However, this doesn't mean potatoes are inherently off-limits for those with type 2 diabetes. In fact, the American Diabetes Association (ADA) encourages the inclusion of starchy vegetables in a balanced and healthy diet [1].
Let’s review how potatoes impact blood sugar levels and go over some tips on how to best enjoy them if you have type 2 diabetes.
Do potatoes raise blood sugar levels?
The quick and simple answer to this question is “yes.” But that’s because all foods with carbohydrates raise blood sugar— a normal physiological process. When it comes to carbohydrate-containing foods, we want to focus on how quickly and how high they raise blood sugar. For this, we can use the glycemic index (GI).
The glycemic index is a system that assigns a number, on a scale of 1-100, to carbohydrate-containing foods based on how much the food raises blood sugar levels. The higher a food’s GI, the faster it raises blood sugar levels. Generally speaking, if a food scores above 70, it’s considered high GI. The GI index is categorized as the following:
- Low GI: 55 or less
- Medium GI: 56 to 69
- High GI: 70 to 100
From Russet to Yukon Gold to Red Bliss, there are many kinds of potatoes—each with their own GI values that vary based on the cooking and preparation method. Though in general, potatoes fall into the medium and high GI ranges.
There’s no getting around the fact that potatoes have medium to high GI values. So how can they still play a role in a healthful diet? Well, let’s get into it.
Can you eat potatoes without dramatically spiking your blood sugar levels?
Here at Reversing T2D, our approach teaches people how to reverse their insulin resistance—which is the root cause of type 2 diabetes. Once they achieve this goal, whole, plant-based foods such as potatoes no longer cause dramatic blood sugar spikes. To learn more about our approach to reversing type 2 diabetes, consider registering for our free Blood Sugar Transformation Week by clicking here.
However, if you’re still insulin resistant, that’s okay! There are still ways you can incorporate potatoes into your diet without experiencing dramatic blood sugar spikes. Below you’ll find helpful information and tips on how to strategically enjoy potatoes if you haven't yet reversed your insulin resistance.
What is the best variety of potatoes for those with diabetes?
As we mentioned above, not all potatoes have the same impact on your blood sugar levels. Interestingly, even if your potatoes are of the same variety, they can still impact your blood sugar levels differently depending on how they’re prepared. Because the preparation method plays a role in determining a potato’s GI value, it’s tricky to say that any one potato variety is inherently best for those with diabetes. But in general, some potato varieties elicit a more favorable glycemic response.
Generally speaking, waxy potatoes (e.g., red and fingerling) tend to have a lower GI than starchier varieties (e.g., Russet and Idaho). Sweet potatoes, however, tend to have an even lower GI than all of the aforementioned waxy varieties. This is why sweet potatoes are most commonly recommended for those with diabetes.
You might be surprised to learn that sweet potatoes are not technically potatoes. Even though both are root vegetables, they’re only distantly related. Despite this distinction, sweet potatoes are often grouped with regular potatoes due to their similar consistency and cooking methods.
Classifications aside, sweet potatoes are commonly touted as the “potato” of choice for those with type 2 diabetes. Not only do sweet potatoes have a relatively low GI (compared to other potatoes), but they’re also packed with other key nutrients such as calcium, vitamin A, beta carotene, and fiber.
Although it’s important to be mindful of the type of potato you’re consuming, the preparation and cooking methods are just as, if not more, important.
What's the best way to cook potatoes for those with type 2 diabetes?
As we touched on earlier, the way you prepare and cook your potatoes can drastically affect the nutritional value of your dish.
Did you know that eating a whole potato rather than a diced or mashed potato will have a more favorable effect on your blood sugar levels? Why is this the case? Well, cooking is a form of external pre-digestion. When you dice or mash potatoes, you’re making it easier for your body to break down the potato and thus raise your blood sugar level.
In general, regardless of potato variety, boiling tends to result in the lowest GI values. Next comes baking, which tends to yield medium to high GI values. Finally, mashed and instant potatoes tend to be associated with the highest GI values.
Another factor to be aware of is the effect that cooling has on the glycemic index of potatoes. When you boil your potatoes then cool them in the refrigerator, their starch composition changes for the better. Potatoes contain a particular kind of starch called resistant starch. This type of starch is harder to digest than normal starch and can help lower potatoes' glucose-raising effect.
For example, one study found that freshly boiled red potatoes had a GI of around 89 but, once cooled, the GI had decreased to around 56 [2]. Interestingly enough, reheating these chilled potatoes doesn't cancel out this GI-lowering phenomenon. Because of this, feel free to cook, cool, and re-heat your potatoes if you’d still like to enjoy them warm.
We also recommended that you leave the skin on potatoes whenever possible. Not only is the skin full of key nutrients such as magnesium and potassium, but it's also rich in fiber. This fiber boost can play a significant role in decreasing the glucose-raising effect of potatoes.
Finally, be mindful of the effect that frying has on potatoes. The act of frying in oil increases your potatoes’ fat content—which will actively work against your ability to reverse your type 2 diabetes. To learn more about why we recommend limiting oil, read Reasons to Limit Oils If You Have Type 2 Diabetes. Instead of frying, opt for other cooking methods, such as roasting or air frying. Not only do alternative cooking methods tend to result in a more favorable glycemic response, but they also have the added bonus of ensuring that the fat, salt, and sugar content is kept to a minimum.
What should I eat with potatoes if I have diabetes?
When deciding what to eat alongside your potatoes, recognize that potatoes are serving as the starchy vegetable for that meal. It’s then important to balance out your plate by incorporating a vegetable that’s lower in carbohydrates, such as broccoli or spinach, and an added protein source, such as tofu or lentils. For more guidance on creating balanced, plant-based dishes, read Using Plant-Based Foods to Reverse Type 2 Diabetes.
Remember, to also be mindful of any toppings you may choose to add to your potatoes. Common potato toppings such as sour cream and bacon are high in saturated fat and dramatically lower the healthfulness of your dish. Instead, consider healthier alternatives like plant-based yogurt, nutritional yeast, chives, ground black pepper, and sea salt.
What are some swaps for potatoes?
As with everything, moderation is key. If you follow our advice above, it's perfectly fine to enjoy potatoes with your meals throughout the week.
However, remember the importance of variety. So many amazing whole, plant-based foods serve as great swaps for potatoes. Below are some examples:
- Cauliflower: Cauliflower is one of the most common substitutes for potatoes. This is because it’s much lower in carbs and calories but still is packed with fiber, vitamin C, and vitamin K. It’s white color and mild flavor are also great for emulating mashed potatoes. Consider trying mashed cauliflower but be mindful of the ingredients you add to achieve your desired texture.
- Whole grains: Instead of having potato as your side dish, consider using a whole grain such as brown rice or quinoa instead. Whole grains are nutritious, and their high fiber content plays an important role in blood sugar regulation.
- Root vegetables: Even if you’re unaccustomed to cooking with turnips, rutabaga, or carrots, root vegetables like these and others tend to be great swaps for potatoes. Whether you’re in the mood for something baked, mashed, roasted, or air fried, there are plenty of recipes online for all sorts of root vegetables!
Let's recap: potatoes and type 2 diabetes
All-in-all, if you have pre- or type 2 diabetes, you can absolutely still incorporate potatoes into your diet. Just remember to be mindful of your preparation and cooking methods, serving sizes, and what you choose to enjoy with your potatoes.
If you’d like to learn more about how you can reverse your pre- or type 2 diabetes and avoid dramatic blood sugar spikes altogether, click here to register for our free Blood Sugar Transformation Week.
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