The glycemic index, or GI, is a tool for evaluating the ability of foods containing carbohydrates to raise blood sugar. When blood sugar increases, the hormone insulin is released to metabolize it. If the increase is very high, the insulin that’s acting to quickly move sugar out of the blood causes a sharp drop in blood sugar. This causes a so-called “crash” that can leave you feeling lethargic.
Eating an excess of foods that cause sharp spikes in blood sugar can make it hard for the pancreas to keep up with insulin production. That can eventually lead to type 2 diabetes, among other health issues.
Foods with a low GI result in smaller fluctuations in blood glucose (sugar) and insulin after eating, while foods with a higher GI cause larger fluctuations in your blood sugar and insulin levels. Low GI foods are associated with maintaining weight loss, as well as a reduced risk of developing type 2 diabetes or heart disease. A value of 55 and under is considered low, between 56 and 69 is medium, and 70 and above is high.
The GI value of foods can vary significantly based on processing or cooking methods, ripeness, and fiber content. It may even vary across different varieties of the same fruit or vegetable — for example, the GI of a Braeburn apple is 32, while the GI of a Golden Delicious apple is 39.
Low GI Fruits
Many fruits have a low GI value. This makes them good choices for keeping your blood sugar levels steady and maintaining optimal health. Fresh fruits that range from 0 to 55 on the GI include (from lowest GI value to highest):
Plums
Asian pears
Peaches
Cherries
Pitted prunes
Braeburn apples
Strawberries
Bartlett pears
Apricots
Navel oranges
Bananas
Keep in mind that drying, baking, stewing, peeling, or otherwise altering these fruits will likely change their GI value. Make sure you’re looking up the GI value for the fruit as you intend to eat it.
Medium GI Fruits
Many fruits have a medium GI value, which ranges between 56 and 69. Although these fruits do not produce as sharp a rise in your blood sugar levels as a high GI food would, their influence over your blood sugar and insulin levels is higher than that of low GI fruits. Such fruits include:
Raisins
Lychees
Kiwifruit
Papayas
Mangoes
Persimmons
Cranberries, dried, sweetened
Grape juice
Cantaloupes
Pineapples
Breadfruit
High GI Fruits
Eating high GI fruits, especially in large quantities, can cause your blood sugar levels to rise quickly. Fruits that range from 70 to 100 on the GI include:
Maktoomi dates
Pomelo
Watermelon
Low GI Vegetables
Most vegetables have a low GI. If you are aiming to lower your dietary GI, you can include an abundance of vegetables to help keep your blood sugar levels more stable. Low GI vegetables include:
Kale
Brussels sprouts
Spinach
Broccoli
Cauliflower
Tomatoes
Carrots, raw
Peas
Sweet corn
Medium GI Vegetables
Medium GI vegetables can be part of a healthy and balanced low GI diet if eaten in moderation. Vegetables with a GI of 56 to 69 include:
Beetroot, boiled
French fries, oven-baked
New potatoes
Pumpkin, boiled
High GI Vegetables
Eating high GI vegetables can result in a sharp increase in your blood sugar levels, potentially leading to a crash once insulin does its job of moving sugar from the blood. Vegetables with a GI of 70 to 100 include:
White potatoes, roasted
Carrots, boiled
Corn, boiled
Potatoes, mashed
Russet potatoes, baked
Sweet potatoes, fried, roasted, or baked
Yams
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Lynn Grieger is a registered dietitian-nutritionist, certified diabetes care and education specialist, certified personal trainer, and certified health and wellness coach. She completed requirements to become a registered dietitian at Valparaiso University in 1987 and completed a dietetic internship at Ingalls Memorial Hospital in Harvey, Illinois, in 1988.
Lynn brings her expertise in nutrition, exercise, and behavior change to her work in helping people reach their individual health and fitness goals. In addition to writing for Everyday Health, she has also written for websites and publications like Food and Health Communications, Today's Dietitian, iVillage.com, and Rodale Press.She has a passion for healthy, nutrient-dense, great-tasting food and for being outdoors as much as possible — she can often be found running or hiking, and has completed a marathon in every state.
Aglaée Jacob is a Canadian registered dietitian and author who shifted from conventional clinical practice to a holistic, real-food, and functional nutrition approach focused on digestive healing and disordered eating recovery. Jacob is the author of Digestive Health With Real Food. She has over 15 years of professional experience.
