What’s so Hard about the Glycemic Index?

Although I agree with you, the glycemic index isn't that difficult, it does become less intuitive when you start "combining" foods (like into recipes). Sure, it's easy to compare a piece of watermelon with an apple. But what about my two dinner choices tonight: bean loaf and stir fry with tempeh and brown rice? I don't really know; my guess is the stir fry is lower because of all the veggies, but it's really just a guess, especially if I'm going to eat it with brown rice. Then again, if I make the bean loaf with chana dal and barley (reasonably low on their own), maybe the loaf is better. So the GI is great when you're eating single foods (a meal of, say, a piece of chicken, a vegetable, a salad, and a potato) but less so if you're making casseroles, soups or other more complicated dishes. This is not to say we shouldn't do our best, but I'm a fairly intelligent, informed, and motivated person and often the best I can do is make a guess. (And, of course, many, many of the foods I eat as a vegan aren't on any of the published lists. Sigh.) David's Response: Thank you for raising what many people see as the "mixed meal problem" with the glycemic index. Calculating the GI of the mixed meal can take a little work, although I show on my glycemic index page at www.mendosa.com/gi.htm how it's done. But it's not necessary. To eat low glycemic just skip the rice. Or eat very little of it. Or eat the lowest glycemic rice, which is Uncle Ben's Converted Rice. You really don't need to know what the overall glycemic index of your eating is. All you need to do is to avoid or minimize high glycemic foods. As to those foods that you eat as a vegan that aren't on the list, almost all of them are missing because they will affect your blood glucose so little. I list them at www.mendosa.com/freefoods.htm

One more thing: If the ADA would get behind the concept of the glycemic index, I'm sure more diabetics would understand it. However, they persist in pushing their high GI diet on diabetics, causing more harm than good. They also have publicly stated that it's "too complicated" for diabetics to understand. Hooey! They should present it to diabetics and let the individual decide if it's too complicated for them. I'm sure if they understood how the chance of diabetic complications can be significantly lessened by using the glycemic index, more would be interested. Instead, diabetics are told that "progression is inevitable". Well, yes, certainly it is, if one continues to follow the ADA guidelines for eating.

Hi David, Now I finally got bloglines to work so I am notified when there is something new on your blog - thanks. One problem with this is that you are NOT notified if a new comment occurs on a blog which you have already read and at which you have placed a question. Concerning this current blog entry about the glycemic index and load: in studying your Revised International Table of Glycemic Index and Glycemic Load Values - 2002, I would like to mention two things. First of all I was so surprised to see that the same product produced in different countries had different glycemic loads and indices. For example Kellogs cornflakes in the US and in Australia are not at all the same! This surprised me! The same product purchased in different countries can affect bg values quite differently. I had myself discovered this in another way during the summer when I purchased Knorr's Broccolli and Cauliflower Powdered soup in Sweden and in Belgium. Both how you prepare the two powdered soups and their nutrient values differed in the two countries. This makes life even more complicated! Secondly although the above glycemic list is very detailed it is difficult to use since, for example concerning the Swedish breads, the brand names are often not given. It is impossible to know which brand one is talking about! I could not with the help of the list find a suitable bread in Sweden.This definitely reduces the value of the "detailed" list.

I'm not diabetic but prediabetic, & began to change my normal diet last December as a crucial step in avoiding diabetes. The first thing I changed was to go low GI, & it had immediate benefits. Not just to lower my blood sugar, but also it led to a complete loss of what had been a longstanding problem: acid reflux. I found it incredibly easy to go low GI. I simply kicked almost all refined carbs out of my diet, replaced them with whole foods, & moderated my intake, especially of breads, pastas, & rice. I too am puzzled by how difficult some people seem to find it. I am also puzzled by the American Diabetes Association continuing to push its high GI diet on diabetics -- a diet that I hold in no small part responsible for my mother's death last year of complications of diabetes. Your website was one of my earliest resources on GI. Thank you.

I guess I'm a big dummy, because I am confused after reading your charts. Some foods, such as watermelon, have high GI values but low GL values. Is it bad or good? It's enough to make you give up eating - if only I could. David's Response: Yes, the carbohydrate in watermelon, for example, has a high GI. But there isn't a lot of it, so watermelon's glycemic load is relatively low. This is another example about the de minimis rule that I wrote about (http://blogs.healthcentral.com/diabetes/david-mendosa/the-fructose-puzzle-2006-07-14/print). Just don't eat a whole large watermelon.