Eating fruit can be a great way to sweeten up a hot summer day. The glycemic index can help you determine the best ones to reach for at your next picnic.
People living with type 2 diabetes know that not all carbohydrates are created the same. Sure, they’re all processed into sugar by your body to supply energy, but that process varies from one carb to the next.
The most important consideration when determining which carbs to eat is how they’ll affect your blood sugar levels.
More complex carbs — including foods higher in fat and protein and whole plant foods like beans and potatoes — take longer to be absorbed, so they provide a slower, more consistent rise in blood sugar.
Less complex carbs — think processed foods and simple sugars — are absorbed quickly and provide more drastic rises and falls in blood sugar, taxing your body’s sensitivity to insulin.
Generally speaking, the glycemic index sorts foods along this spectrum. Foods with a lower glycemic index score will affect your blood sugar in a slower, less dramatic fashion. Foods higher on the glycemic index will cause faster and quicker ups and downs in blood glucose levels.
As a general baseline, foods with a glycemic index score below 55 are considered low glycemic, 55 to 69 is considered a moderate range, and 70 and above is high.
That said, the glycemic index should be used only as a loose guide. Every individual processes food differently. That’s why it’s important to keep an eye on your blood sugar levels and to pay attention to which fruits have a better effect than others.
It’s also important to keep in mind the overall nutrition value of the carbohydrates you eat. Some fruits are more nutrient-dense than others, and each fruit contains different nutrients. Even the preparation and ripeness of the fruit can affect its glycemic index score.
Of all the carbohydrates, fruits are among the most commonly misunderstood. People often assume they’re in the simple sugars category, but that’s not really correct. While they may be sweet and tasty, whole fruits are also chock full of other important nutrients, like fiber and essential vitamins and minerals.
“Whole fruits are nutritious and a much better alternative than highly processed desserts or other sweet foods,” says Julie Grim, the director of nutrition at the American Diabetes Association. “With the right portion sizes, fruits can help satisfy your craving for less healthy sweet foods such as cakes and cookies.”
As the weather heats up this summer and your desire for something fresh and sweet increases, consider reaching for the following fruits that fall on the lower end of the glycemic index.
Apples are one of the lowest glycemic fruits you can find. In a 2013 study, researchers even found that greater consumption of apples, blueberries, and grapes was associated with a significantly lower risk of type 2 diabetes.
And don’t toss the peel! Most of the fiber is in and under the peeling, which can make a significant difference.
Portion size: Whole apples tend to be around 150 to 200 grams, and a medium-sized 180-gram apple will have 25 grams of carbohydrates. Aim for one whole small apple (which is about the size of a tennis ball), a little less than 1 cup of chopped apple, or half of a large apple. Each of those portions should yield about 125 grams, including around 15 grams of carbohydrates.
Glycemic index score: 38
While just under the 55 score required to be considered a low glycemic fruit, blueberries are arguably the best of the bunch when it comes to overall nutrition. Strawberries, blackberries, and raspberries are all good options, too.
Keep in mind that fresh is not the only way to enjoy berries — frozen berries are perfectly fine, as long as there aren’t added sugars or other preservatives.
Portion size: A 3/4-cup serving of blueberries will get you 15 grams of carbohydrates. That might be a lot for most people, so feel free to mix it up by adding some strawberries: 1 1/4 cup of raw, halved strawberries equals 15 grams of carbs. For raspberries, 1 cup comes to 15 grams of carbohydrates.
Glycemic index score: 53 (blueberries); 40 (strawberries); 32 (raspberries); 25 (blackberries)
While lemons and limes fall on the lower end of the glycemic index, oranges and grapefruits are the easiest citrus fruits to eat whole. Plus, who can say no to orange wedges on a hot summer day?
Portion size: One medium- to medium-small orange (roughly the size of a tennis ball) has about 15 grams of carbohydrates. Grapefruits tend to be much larger, so aim for about half a grapefruit (or less) to get 15 grams of carbs.
Glycemic index score: 42 (orange); 25 (grapefruit)
It might not be easy to find a perfectly ripe pear, but when you do, it’s worth it. Pears are not only delicious and juicy, but they also provide a ton of fiber, helping you feel satisfied and improving digestion.
Portion size: A 3/4 cup of sliced pear will yield 15 grams of carbs, which is a little more than half of a medium-sized pear.
Glycemic index score: 38
Bananas are right on the border of low glycemic, but that’s because the typical medium banana is around 23 to 25 grams, instead of the 15 grams assumed for the other fruits. Instead of avoiding bananas and missing out on this nutrient-dense, potassium-packed, easy-to-eat treat, simply eat half a banana for one portion.
And don’t forget to store the other half! A little saran wrap over the cut end of the banana helps keep the end from turning brown, and refrigerating the banana helps too. If you like smoothies, you can even freeze the banana half for later.
Portion size: Half a banana should be right around 15 grams of carbs.
Glycemic index score: 52 (when considering 24 grams of carbs)
Mangoes fall right on the borderline of what’s considered low glycemic, coming in at 51 on the glycemic index, although this number varies. It’s important to pay close attention to how this fruit affects your own personal blood sugar levels.
Portion size: Aim for between 1/2 cup and 2/3 cup of mango slices for 15 grams of carbs.
Glycemic index score: 51
The issue with peaches and plums is that they can vary a lot, a bit like mangoes. A 2021 systemic review had plums ranging from a score of 24 on the glycemic index to 53. Peaches had similar results.
These variations can be due to the way the study was administered (using different reference foods and time periods, for example) and depend on where the food was grown and how ripe it was. The important thing is to once again monitor how the peaches and plums you buy affect your individual blood sugar.
Portion size: One medium peach (the size of a tennis ball) has 15 grams of carbohydrates. With smaller plums (about the size of a golf ball), you may be able to eat 2 fruits as a serving
Glycemic index score: 42 (peaches, average of 2 studies); 39 (plums, average of 2 studies)
There are some fruits you may want to limit this summer in order to manage your blood sugar levels. Consider the carb content of each and make adjustments to your eating plan to stay within your carb budget as necessary. For example, if you’re having a burger, ditch the bun, eat it “protein-style,” and enjoy watermelon as dessert!
Watermelon on a hot summer day can be tantalizing, so if you want to enjoy make sure you’re staying within your established nutrient budget.
Portion size: 1 1/4 cup of watermelon cubes will yield 15 grams of carbs, but it might be better to eat less to avoid blood sugar issues. If you find yourself enjoying more of the hydrating, sweet summer treat than you anticipated, do your best to make concessions in other parts of your meal.
Glycemic index score: 72
Tropical fruits in general don’t do great when it comes to the glycemic index. On the other hand, pineapple is a great source of fiber and can satisfy most sweet tooths with just a wedge or two.
Portion size: About 3/4 cup of pineapple cubes will net 15 grams of carbs. As with watermelon, it might make the most sense to aim for less, and definitely watch out for canned pineapple swimming in syrup. Fresh or frozen (without added sugars) will generally be best.
Glycemic index score: 62
Grapes are packed with antioxidants and potassium and make a great snack on a hot afternoon. But given their size, it can be easy to lose track of how much you’ve eaten.
Portion size: 1/2 cup will usually net you 15 grams of carbs. Depending on the size of the grapes, that should be around 10 to 15 grapes. Bonus tip: Instead of sitting down with a bag of grapes or a packed vine, measure them out beforehand so you don’t end up eating more than you planned.
Glycemic index score: 59
Fruit juice is tricky because it contains a lot more carbs in a much smaller serving. Eight ounces of apple juice, for example, has 29 carbs.
The other issue is that when you juice a fruit, you get rid of the fiber, which is a natural aid in slowing down digestion and smoothing out blood sugar levels.
It’s also best to limit dried fruit for a similar reason — they tend to pack in more carbs per portion. Popular dried fruits like raisins, for example, have the same amount of carbs in 2 tablespoons as a small apple.
For all other preparations, including canned fruit or frozen fruit, pay attention to if there are any added sugars or other additives. Canned fruit isn’t necessarily bad, but if it’s stored in sugary syrup, that’s a lot different than if it’s in its own juices.
While the glycemic index can be helpful in determining how the carbohydrates you’re eating will affect your blood sugar, there are other considerations to keep in mind.
Perhaps the most important is that every individual processes food differently. Just as there’s no one-size-fits-all, perfect diet out there, there’s no such thing as a perfect food or fruit. That’s why it’s important to keep an eye on your blood sugar levels and to pay attention to which fruits have a better effect than others.
It’s also important to keep in mind the overall nutrition value of the carbohydrates you eat. Some fruits are more nutrient-dense than others, and each fruit contains different nutrients.
Avocados, for example, have good healthy fats, not a lot of carbohydrates, and rank low on the glycemic index. They can be great if you need more healthy fats, but if you already eat a lot of nuts, then you might not need those fats.
That’s just one example — the same principle applies to all foods.
When it comes to timing, many experts recommend spreading out your fruit intake over the day, instead of in one meal. That should help with the overall goal of consistent and steady blood sugar levels.
Medically reviewed on July 11, 2022
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