If you have diabetes, controlling blood sugar is key to staying healthy. Some people use the glycemic index (GI) to help choose foods that will keep their blood glucose levels steady. Know, though, that index is not the only tool that can help you keep a healthy blood sugar level.
The GI index ranks carbohydrate-containing foods by how much they spike blood sugar, notes the Mayo Clinic. For people with diabetes, this metric can help identify which foods to avoid. But it's not the only measure that matters. Researchers say you should also watch calories, fat, fiber, vitamins and other nutrients, Mayo Clinic points out.
Read more: A List of High-Glycemic Carbs
"The school of thought is that low-GI foods do not elevate blood sugar as quickly or as high [as other foods]," says Vicki Shanta Retelny, RDN, a dietitian/nutritionist and consultant to Northwestern Memorial Hospital in Chicago. "This means they don't require as much insulin to get the blood sugar into the cells." She adds that low-GI foods — those with scores of 55 or less — also typically sustain energy levels more steadily over time.
It sounds logical that low-GI diets can be beneficial for people with diabetes. But according to a review of 73 studies published in September 2018 in the journal Nutrients, there isn't a clear case for using GI-based diets as a diagnostics tool or medical treatment for health issues such as diabetes or obesity. The study concluded that focusing on overall dietary quality and promoting the healthful aspects of fiber, fruit and vegetable intake could be a more successful approach.
Mayo Clinic also cautions against relying solely on the GI for nutritional guidance, stating that a GI score doesn't take other nutritional information or food quantity into account.
Based on GI score alone, for instance, you might decide to steer clear of pineapple. It's a medium-GI fruit, says the American Diabetes Association (ADA). But pineapple is fat-free and full of fiber, says according to the U.S. Department of Agriculture, and that makes fruit a nutritious choice, the ADA says. On the other hand, the index can help identify unhealthy high-GI foods, like refined starches and sugar-rich snacks. So, consider it one tool in your arsenal to control diabetes.
Low Glycemic Index Foods
According to Harvard Health Publishing, GI index can be broken down into three segments:
- Foods with a low GI score (55 or less).
- Foods with a medium GI score (56 to 69).
- Foods with a high GI score (70 and above).
High GI foods include white bread, cake, crackers, bagels, doughnuts and most breakfast cereals, says Harvard Health. On the low end of the spectrum? A bounty of options, including most fruits and vegetables, beans, grains that are minimally processed, pasta, low-fat dairy and nuts, it adds.
A list of common foods and their GI scores, compiled by the University of California San Francisco, includes several healthy options to choose from if you're hoping to eat only low-GI meals and snacks:
- Grains and Legumes
- Peanuts, 1/4 cup: 14
- Rice cake: 26
- All-bran cereal, 1 cup: 38
- Kidney beans, 1 cup: 28
- Apple, medium: 38
- Grapefruit, 1/2 large: 25
- Pear, medium: 38
- Dairy and Dairy Alternatives
- Skim milk, 1 cup: 32
- Yogurt, plain low-fat: 33
"Low-GI snacks are higher in fiber and less refined carbohydrates," says Retelny. She recommends pairing low-GI carbohydrates with protein to help stabilize blood sugar even more. Some of her favorites are a small apple with a handful of nuts, whole-grain crackers with cheese, and plain yogurt topped with berries. For a heartier snack, stuff half of a whole-grain pita with leafy greens and a dollop of tuna fish.
If you have diabetes and are interested in changing your diet to control blood sugar, talk to your doctor or a certified diabetes educator about finding the right nutrition plan for you and whether to use the GI index to help you make better choices.
Read more: Low-Sugar Fruits and Vegetables
- Mayo Clinic: “Glycemic Index Diet: What's Behind the Claims”
- Vicki Shanta Retelny, RDN, dietitian/nutritionist, author, consultant, Northwestern Memorial Hospital, Chicago
- Nutrients: “Relevance of the Glycemic Index and Glycemic Load for Body Weight, Diabetes, and Cardiovascular Disease”
- University of California San Francisco: “Glycemic Index and Glycemic Load”
- American Diabetes Association: “Fruit”
- U.S. Department of Agriculture: “Nutrition Facts for Pineapple"
- Harvard Health Publishing: "A Good Guide to Good Carbs: The Glycemic Index"