Your mother was just diagnosed with type 2 diabetes. She wants to improve both her eating habits and her glucose control. After an Internet search, she has decided to try out a new diet that uses the glycemic index in meal planning. She asks you if you think the diet is practical and beneficial. How do you respond?

Question

What will be an ideal response?

Answer 1

The glycemic response refers to how quickly glucose is absorbed after a person eats, how high blood glucose rises, and how quickly it returns to normal. Slow absorption, a modest rise in blood glucose, and a smooth return to normal are desirable (a low glycemic response). Fast absorption, a surge in blood glucose, and an overreaction that plunges glucose below normal are less desirable (a high glycemic response). The glycemic response may be particularly important to people with diabetes, who may benefit from limiting foods that produce too great a rise, or too sudden a fall, in blood glucose.
Different foods elicit different glycemic responses; the glycemic index classifies foods accordingly. Some studies have shown that selecting foods with a low glycemic index is a practical way to improve dietary adequacy and glucose control. Lowering the glycemic index of the diet may improve blood lipids, reduce inflammation, and lower the risk of heart disease as well. A low glycemic diet may also help with appetite regulation and weight management, although research findings are mixed.
Researchers debate whether selecting foods based on the glycemic index is practical or offers any real health benefits. Those opposing the use of the glycemic index argue that it is not sufficiently supported by scientific research. The glycemic index has been determined for relatively few foods, and when the glycemic index has been established, it is based on an average of multiple tests with wide variations in their results. Values vary because of differences in the physical and chemical characteristics of foods, testing methods of laboratories, and digestive processes of individuals. Calculating the glycemic index for meals or diets based on individual foods greatly overestimates the values.
Furthermore, the practical utility of the glycemic index is limited because this information is neither provided on food labels nor intuitively apparent. Indeed, a food’s glycemic index is not always what one might expect. Ice cream, for example, is a high-sugar food but produces less of a glycemic response than baked potatoes, a high-starch food. Perhaps most relevant to real life, a food’s glycemic effect differs depending on plant variety, food processing, cooking method, and whether it is eaten alone or with other foods. Most people eat a variety of foods, cooked and raw, that provide different amounts of carbohydrate, fat, and protein—all of which influence the glycemic index of a meal.
Paying attention to the glycemic index may be unnecessary because current guidelines already suggest many low and moderate glycemic index choices: Whole grains, legumes, vegetables, fruits, and milk and milk products. In addition, eating frequent, small meals spreads glucose absorption across the day and thus offers similar metabolic advantages to eating foods with a low glycemic response. People wanting to follow a low-glycemic diet should be careful not to adopt a low-carbohydrate diet as well.