I recently learned and wrote about a study connecting high glycemic index diets to cancer, diabetes, cardiovascular diseases and gall stones. Since then, I read an article at CalorieLab about the glycemic index and how high or low glycemic diets can affect your health. Particularly interesting is the physiological explanation for why selecting low glycemic index foods is important:
Carbohydrate with a high GI is digested quickly, resulting in a rapid elevation of blood sugar and a swift rise in insulin. Most sweets, but also potatoes, white rice and refined cereals and breads fall into this category.
Foods with a low GI are digested and absorbed more slowly, causing a more gradual rise in blood sugar and preventing rapid spikes in insulin levels. These foods include whole-grain breads, pasta, beans and most fruits and vegetables.
Also of note were studies that revealed overweight/obese or insulin-resistant subjects lost more weight on low glycemic index diets than low fat diets. However, one shouldn’t focus solely on the glycemic index when selecting foods, as many healthy foods (like some whole grains) fall fairly high on the index. As the article says,
A review of how carbohydrate choice and amount affect weight control notes that eating more whole grains is usually linked to healthier weights, whereas eating more refined grains is not. This is significant because whole grain choices, including grains like oatmeal, bulgur and brown rice, are not necessarily low-GI.
In theory, keeping in mind the GI of foods to lower risk of diabetes, overweight, and perhaps even heart disease and cancer makes sense. However, focusing on an exclusively low-GI diet could lead some people to adopt a less healthful eating pattern. This is particularly concerning if people exclude some higher GI, yet healthful foods and include excessive amounts of high-calorie, fatty foods or alcohol just because they are low-GI.
The moral of the story? While the GI may not be the “magic bullet” to weight loss, it should play an important role in selecting the foods you eat. You can find more information about the GI at the official website of the Glycemic Index.
