Glycemic Response

Because of their carbohydrate content and purported high glycemic index, potatoes are not only frequently restricted in diabetic dietary guidance, but are also implicated in the development of the disease. While there is some limited epidemiological evidence of an association between high glycemic index foods, including potatoes, and diabetes, there are no clinical/experimental trials demonstrating a cause and effect relationship.

Glycemic index of individual foods does not predict glucose or insulin responses to a mixed meal in children or adults, nor does a low-GI diet improve cardiovascular risk factors or insulin resistance.

• A 2022 randomized controlled trial published in the American Journal of Clinical Nutrition found that adding a 300-calorie serving of French fries to one’s typical diet every day for a month does not result in differential short-term changes in key biomarkers associated type 2 diabetes compared to adding an isocaloric daily serving of almonds, generally considered a healthy snack option. Changes in body fat mass, body weight, fasting glucose levels and fasting insulin levels at the end of the one-month trial were comparable across the French fry and almond intervention groups and were not clinically significant.
• A 2017 study published in the American Journal of Clinical Nutrition indicates that glycemic index may be a very unreliable marker of blood glucose levels when carbohydrates are consumed with protein, as part of a mixed meal (1).
• A multi-center human randomized, cross-over controlled feeding trial comparing diets with high and low glycemic index of dietary carbohydrates showed no differences in improvements in insulin sensitivity, lipid levels or systolic blood pressure. Selecting specific foods based on glycemic index may not improve cardiovascular risk factors or insulin resistance in overweight adults (2).
• A human randomized control trial of diets with high and low glycemic load and 30 percent caloric restriction showed no differences in changes in hunger, satiety or satisfaction with the amount and type of food provided during caloric restriction.
• Weight loss diets differing substantially in glycemic load induce comparable long-term weight loss (3).

Specific to potatoes, research shows that when potatoes are eaten as part of a mixed meal, the post prandial blood glucose levels are more desirable than when other common carbohydrate sources are eaten.

• Research suggests that the glycemic index of a food is not a reliable predictor of energy intake and glycemic response. A 2016 study, supported by APRE, found that kids who eat French fries as a side dish to a meta-based entrée had lower levels of blood glucose and plasma insulin following the meal, compared to when they ate other carbohydrate-based side dishes (4).
• Satiating amounts of potatoes eaten with meat lead to lower energy intake and postprandial insulin compared with rice and pasta in normal-weight male subjects (5).
• Research, supported by APRE, found that mashed boiled potatoes in a meal with protein lead to lower caloric intake among healthy, normal-weight children. Insulinemia was significantly lower after a meal with deep-fried French fried potatoes than other carbohydrate sources (6).

For more information on potatoes and glycemic response, read:

For more information on potatoes and weight management, read:

• Potatoes, Nutrition and Health: A Review, pages 14-15.