Alliance for Potato Research & Education

The Glycemic Index Offers More Confusion than Help

Patients and clients often ask me if the glycemic index (GI) should factor into their food choices. They wonder if planning meals around the GI will help them and their families feel more satisfied, get better nutrition, or stabilize blood sugar levels. I get that meal planning—whether for a large family, a small one, or just for oneself—can be challenging. The last thing I want to do is add barriers, especially meaningless ones, to successful meal planning. That’s why I skip right over the GI and focus on taste, nutrient density, calorie density, variety, budget, cooking skills, and convenience—all things that are far more important than the GI.

A recent study presented at Experimental Biology (EB) 2015 in Boston, MA helps to make my point that the GI has little, if any, importance when foods are eaten as part of a meal. Dr. G. Harvey Anderson of the University of Toronto presented research conducted on a population of healthy boys and girls aged 11-13 years. Dr. Anderson and other researchers compared the effects of rice, pasta, and three potato side dishes served with lean beef on food intake, appetite, and blood sugar levels. Because potatoes tend to have a higher GI than rice and pasta (see below), many people assume that potato consumption would cause a greater blood glucose response and offer little satisfaction of appetite. But that’s not what the researchers found.

Side Dish Glycemic Index
Rice 57
Pasta 64
Baked French Fries 64
Fried French Fries 70
Boiled Mashed Potatoes 91

Dr. Anderson reported that of the five test foods eaten as part of a meal, the fried French fries resulted in the lowest post-meal blood glucose response. These results don’t surprise me. I’ve seen other studies in which the GI of an individual food did not predict the blood sugar response during a meal (1). Additionally, when the children ate the meal with mashed potatoes, they consumed the fewest calories.

These studies should give people one less thing to worry about when planning meals and shopping for groceries. And that’s a big win. I’m thrilled for every obstacle to healthy eating that I can knock over. I never want my patients to skip nutritious foods like the humble spud because they have misguided notions about the value of the GI. Even worse is to give up on healthy eating completely because it appears to be too complex or too much hassle.

Cheers to the wholesome potato and to happy, healthy eating.

 


(1) Dodd H, Williams S, Brown R, Venn B. Calculating Meal Glycemic Index by Using Measured and Published Food Values Compared with Directly Measured Meal Glycemic Index. Am J Clin Nutr 2011 Oct;94(4):992-926. DOI: 10.3945/ajcn.111.012138.