Maybe you’ve heard of it and maybe you haven’t. About 5 or so years ago I predicted it would be the next big “thing” in the diet world. Since the tabloids and celebrities are always trying to make a buck off the next big thing I thought it would be a pretty good one for them to piggy back off of. Turns out I was only partially correct. It didn’t really blow up like the low fat phase in the early to mid 90’s. It certainly didn’t become the heir to Atkins. And it didn’t receive the same reception as the oh-so-glorious gluten free diet. But books were written nonetheless and I receive questions about high and low glycemic foods pretty regularly so I decided it would be a good post to write about.
So what is the glycemic index?
The glycemic index was originally created to aid diabetics in better controlling their blood sugar levels via their diet. Makes sense. And it works pretty well too. But as with gluten, it’s really only applicable to a certain population group. A gluten free diet is necessary for those with Celiac disease. It must be avoided so as to not destroy their intestinal lining. The glycemic index is designed, as I said earlier, to help diabetics. However, it has little carry over to the general healthy population. Here’s how it works: foods are arraigned on a scale from 0-100 with the score representing a certain food’s impact on blood sugar. The higher the score, the more the food raises blood sugar. So for instance, a pop tart would be very high on the scale, likely in the 90’s but I didn’t check. Another example would be rice cakes, white bread, or pineapple. However, on the other end of the spectrum you’d find foods like almonds, green beans, or spinach.
How does the glycemic index work?
Foods receive their scores by having healthy individuals consume 1 portion of a food after an overnight fast that is at least 12 hours in duration. Then, after ingesting the food, the blood sugar of the person is checked to see how much it was affected from their baseline, or fasted, blood sugar level. I’m dumbing this down a bit, but this is the gist of it. But one last (and I think really important) thing to note here is that each food is eaten individually. That is, they are not eating a meal, but rather just a relatively small portion of just one food by itself.
How then, is the glycemic index flawed as a diet?
Well, it just doesn’t translate to the general, healthy population. The reason is that when we eat, we don’t just eat one piece of white bread. Well maybe some of you do on occasion, but it’s extremely rare in what I witness among my clientele. So if you are consuming a high glycemic index food, but it is paired with foods containing fat, fiber, and protein (which almost every meal has), then it doesn’t really matter. This is because fat, fiber, and protein all slow the absorption of sugar into the blood stream thereby pretty much rendering the glycemic number of the food useless.
But what about insulin?
Ah, insulin. Poor insulin. I think the perception of this happy little hormone would be different if people knew it was an anabolic hormone. I also think people would think differently about gluten if they knew it was a protein, but that’s for another post. So here’s the deal with insulin. When we eat, our food gets broken down into small molecules that our bodies can use for energy (and many other things), but for now we’ll focus on energy. Trouble is, these little molecules need help getting into our cells so that they can be utilized. Well, insulin is like the Uber that gets you to your destination. It picks up the molecules and transports them into the cells. And for this discussion, we’re referring specifically to sugar, or glucose. Now our cells are happy and have plenty of energy available to them. However, since you also ate a meal containing protein and fat, those molecules are floating around in your blood too. But since the cells are happy with the energy they have at their disposal, the body decides that it should probably store these fat molecules for later just in case there’s a period of time in which we can’t eat. This is where insulin gets a bad rap. People assume that because this process is occurring, then that must make us gain weight. Trouble is, this is no big deal (and normal) as long as we are not overeating. It still comes down to calories in vs. calories out. You see, you’ll use it later and maintain or lose weight as long as you eat at or below what your body needs in a day. It doesn’t matter that you store it. What matters is if you eat above your caloric needs and store too much of it over a period of time.
So with all this said, there are certainly cases to be made for say, whole wheat bread over white bread or whole grain rice over white. You get the nutrients that are stripped out of the refined versions (white bread and rice). You also get the fiber from the bran that was removed from the stripped down versions as well. Obviously fiber aids in digestive health and most Americans don’t get nearly what they need. The point of the post wasn’t to say that it doesn’t completely matter which foods you choose, but rather to point out that the glycemic index concept, as it applies to healthy individuals, is flawed. I’d argue that we need to focus on more important things such as eating at or slightly below our caloric needs. We need to eat more fiber, fruits, and vegetables. That’s where I think we’ll see the most success. Let’s focus on what really matters instead.