Ready to throw out my glycemic index books
I've come across an article about the glycemic index that raises doubts for me after swearing by it for the last few years. Glycemic index (GI) is defined in the article as "a scale applied to foods based on how quickly the
glucose in foods is absorbed into the blood stream, relative to pure
glucose." The concept can be used to lose weight, according to the Glucose Revolution books, and it is incorporated into the South Beach Diet.
I've bought the book and cookbook by Jennie Brand-Miller et al. and tried to follow the concepts. I've avoided white potatoes and eaten sweet potatoes until I couldn't stand them any more. I've favored proteins, trying to choose low-fat ones. I've justified eating ice cream by claiming it has a low GI. I've pigged out on nuts.
This new article, however, implies that you can't count on the GI! It says testing at the at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University showed variations in GI values of 42 percent in individuals eating the same food at different times. It also showed a wide range of values among different individuals. (For purist readers, it was a small study with only 14 participants.)
I know the GI uses averages, but until now I had no idea how wide the range of values was. To me, it makes choosing foods based on the GI meaningless. I could be thinking I'm eating something with a low GI value when my blood sugar could be shooting up just because of who I am or when I eat.
The researchers, of course, plan to do more studies. However, this small study is enough to disillusion me. To tell the truth, I had already drifted away from the GI diet. In the past year and a half I have lost weight by following two general principles: eating the freshest/least processed food possible and eating less. Period. Following these principles, I have not worried about whether individual foods are good or bad, low fat or high fat, protein or carb, low GI or high GI. As far as I'm concerned, this article gives me permission to throw my GI books out the window and keep doing what I'm doing.
I've bought the book and cookbook by Jennie Brand-Miller et al. and tried to follow the concepts. I've avoided white potatoes and eaten sweet potatoes until I couldn't stand them any more. I've favored proteins, trying to choose low-fat ones. I've justified eating ice cream by claiming it has a low GI. I've pigged out on nuts.
This new article, however, implies that you can't count on the GI! It says testing at the at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University showed variations in GI values of 42 percent in individuals eating the same food at different times. It also showed a wide range of values among different individuals. (For purist readers, it was a small study with only 14 participants.)
I know the GI uses averages, but until now I had no idea how wide the range of values was. To me, it makes choosing foods based on the GI meaningless. I could be thinking I'm eating something with a low GI value when my blood sugar could be shooting up just because of who I am or when I eat.
The researchers, of course, plan to do more studies. However, this small study is enough to disillusion me. To tell the truth, I had already drifted away from the GI diet. In the past year and a half I have lost weight by following two general principles: eating the freshest/least processed food possible and eating less. Period. Following these principles, I have not worried about whether individual foods are good or bad, low fat or high fat, protein or carb, low GI or high GI. As far as I'm concerned, this article gives me permission to throw my GI books out the window and keep doing what I'm doing.
Comments