7 Foods With a High Glycemic Index

Medically Reviewed By William C. Lloyd III, MD, FACS
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If you have diabetes, foods with a high glycemic index (GI) can make your blood sugar spike and then drop rapidly. The glycemic index goes from 0 to 100 and measures how quickly your body converts carbohydrates into glucose. However, not all high GI foods have this effect. If the total carbs in a food are low, it will offset a high GI. However, there are foods high on the glycemic index, ranking 70 or more, that can make it more difficult to keep your blood sugar levels balanced. Here are some high GI foods to watch out for.

1. Breads made with white flour 

White bread, bagels, and any other breads made primarily from white flour have a high glycemic index. White flour is processed from wheat that’s had the bran and germ layers removed, so it has less of the fiber you need to slow down digestion and keep blood sugar from spiking. One large slice of white sandwich bread comes in at about 71 on the GI index. If you’re looking for bread alternatives, a large slice of whole grain pumpernickel bread has a GI of about 46.

2. Breakfast cereals 

Many breakfast cereals come in high on the GI index because of their carb content. One cup of cornflakes has a GI of around 79. The GI of oatmeal, which many of us think of as healthy, depends on how it’s been processed. Rolled or quick oats have a GI in the mid-range, at about 55. Instant oatmeal has a much higher glycemic index of about 83. Cereals made only with bran, which has a high fiber content, have a lower GI than many other breakfast cereals at an average 45 per cup.

3. Sugary snacks 

Since most pastries, cakes and cookies are loaded with carbs and sugar, they rank high on the glycemic index. Doughnuts come in at about 76, for instance, but there are some reasonable sweet choices out there. Dark chocolate containing at least 70% cocoa has a GI of only around 23, due to high fat content which slows down digestion. Milk chocolate comes in higher at a GI of 34 to 49, but that’s still a low number. Bear in mind how portion size will affect how well your body can process food without raising your blood sugar.

4. Potatoes 

Potatoes can be literally off the charts on the glycemic index. A medium-sized baked Russet potato has a GI of about 111. White boiled potatoes are a little better but still high, with a GI of about 82. If you’re looking for a healthier starch, pearled barley has a GI rating of around 33, and quinoa is around 55. If you do have potatoes, consider what else is on your plate: Meat, chicken and fish have no carbs and leafy green vegetables like spinach, with a GI of only about 15, can help offset the potatoes.

5. Rice and Pasta

White rice has been processed to remove almost all of the fiber, giving it a high GI of around 73. Brown rice is a bit lower, but you can also try substituting lentils, quinoa or farro, all of which have a much lower GI than rice. Pasta, which you might expect to be high on the glycemic index, is digested slowly so it’s actually a low GI food at a rating of about 45. With the availability of noodle-cut veggies and rice-like cauliflower, you have even lower GI options for a pasta or rice substitute.

6. Sugary soft drinks  

Although soda sweetened with sugar has a lower GI than you might think, coming in at the mid-range around 60 depending on the type of soda, the calories add up. If you are at risk for or have type 2 diabetes, sugary soft drinks can contribute to obesity and are not a healthy option. Diet soft drinks have few carbs and a GI of 0, but they don’t offer any nutritional value, so bear that in mind when choosing a beverage.

7. Certain fruits 

Despite the sugar content, many fresh fruits are low GI because they have a lot of fiber and water. Apples, oranges, and berries are all good choices. Watermelon has a high GI of around 80, but it has very few carbohydrates, so you can eat about 1 ½ cups for a standard portion of 15 grams of carbs. Cantaloupe is similar. Pineapple ranks in the medium range on the GI scale, at about 66, so watch the portion size. Stay away from pineapple juice and canned pineapple, which can have less fiber and added sugar and are more likely to cause a glucose spike. Many dried fruits have a high GI, with apricots and prunes as notable exceptions.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Oct 7
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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