Published April 19, 2008
The glycemic index, whole wheat conundrum
Now that we kind of have an understanding about the glycemic index, I’m going to throw a curve ball at you. Even though I’ve already talked about this, I think the “whole wheat” concept needs to be explained some more because it can be very confusing when trying to decide what to eat.
In fact, whole wheat bread actually has a glycemic index rating that’s the same if not slightly higher than white bread!
As you know, the words “white bread” can send chills up dieters’ backs. Why is that? It’s because everyone knows that the “whites” are bad for you. Just like I said earlier, “whites” raise your blood sugar; white bread, white flour, white rice, white potatoes, white sugar, they all send your blood sugar soaring. Get this, though. Whole wheat bread really isn’t much better. In fact, whole wheat bread actually has a glycemic index rating that’s the same if not slightly higher than white bread! Then why have we been taught to choose whole wheat over white bread? What’s that all about?
The answer is because slice for slice, whole wheat bread has way more nutrients than white bread. Basically, it’s like dipping a piece of paper into some apple juice, and then eating it. Yeah, you’ll get some of the benefits of eating an apple by eating the apple juice-soaked paper, but why not just eat the apple instead? OK, maybe that was an unbelievable exaggeration, but you get my point.
When making white bread, it’s stripped of a lot of the nutrients that are in a grain of wheat, but to compensate for the loss of nutrients during the milling process, an attempt is made to put the missing nutrients back into the bread before it hits store shelves. (I explain all this in better detail here.) White bread can never regain the all the nutrients that left it, just like apple juice-soaked paper can’t regain all the nutrients of an apple itself.
The answer is because slice for slice, whole wheat bread has way more nutrients than white bread.
Here’s another thing, whole wheat bread is more filling than white bread. Since whole wheat bread has more fiber in it, it’ll leave your appetite suppressed for a longer period of time.
This fact means that you can combat the bad effects of a whole wheat blood sugar spike with a suppressed appetite and more nutritious meal, meaning less “useless” calories consumed throughout the day and less excess fat stored in the body.
To sum it all up, whole wheat bread and white bread have about the same glycemic index rating, so they’ll spike your blood sugar just as fast, but whole wheat bread has a lot of other benefits to compensate for this.
Here’s a neat fact, although a little off topic. The blood sugar spikes that come from eating bread result from the body converting starch into glucose. The good news is, when our bodies break down starch into glucose, we can actually pull stored sunlight energy out of starch’s chemical bonds and use it for ourselves. Pretty cool, huh?
Anyway, so whole wheat and white bread result in about the same rate of blood sugar spiking. Like I said, though, to offset the blood sugar spike of whole wheat bread, there’s actually more fiber in whole wheat bread compared to white bread. This means that even though the rate of blood sugar spikes might be the same, with whole wheat bread, you’re going to feel full longer and less likely to succumb to eating more junk food as a result of the blood sugar drop after the initial spike.
This is why whole wheat bread can be considered a better choice than white bread. Even though their glycemic index ratings are about the same, there is more fiber and other nutrients in whole wheat compared to white bread. This fact means that you can combat the bad effects of a whole wheat blood sugar spike with a suppressed appetite and more nutritious meal, meaning less “useless” calories consumed throughout the day and less excess fat stored in the body.
That’s not to say that you can eat as much whole wheat bread as you want; it’s still high on the glycemic index, so you want to eat it in moderation. At least it's a better choice, though, than the less nutritive white bread option.
12 comment(s) on this page. Add your own comment below.
yes but who eats a slice of whole wheat bread on its own. I eat if with fish or cheese etc. doesn't the protein slow down the spiking.
Thanks for the question. You're exactly right and have added to why whole wheat bread is the better choice. We rarely do eat bread by itself, and with the addition of fat or protein to the meal, the blood sugar spike is slowed. All that to say, whole wheat bread is about the benefits with the nutrients not the glycemic index.
VERY good info here and it pretty much can be applied to most all grain foods. Even with fat and protein included to "slow" the insulin spike it still does elevate eventually and stays high for roughly 3-4 hours post eating. That's 3-4 hours of sluggishness and fat storing going on.
To make a statement as absurd as this one that WHOLE wheat has a higher GI than White bread takes all credibility of the author and throws it out the window.. Adding fiber to any carb will lower the GI. White bread has little to no fiber compared to any wheat product...Let alone WHOLE wheat...Not to mention that insulin receptiveness at the receptor site is most important no matter how high or low the GI may be... Receptor sites that are as sensitive as teens can eat cotton candy all day long and stay lean.,..Lets spend more time resensitizing the cells rather than compensating with certain types of carbs...
Agreed that whole wheat contains more nutrients than white bread...but that is only half the story. You really need to take a closer look at the absorption rates of these nutrients in the gut. Even though white bread has less nutrients to start with, they are more easily absorbed and in the end you'll get more nutrition from white bread than whole wheat bread.
Unfortunately, this statement is misleading: "This means that even though the rate of blood sugar spikes might be the same, with whole wheat bread, you’re going to feel full longer and less likely to succumb to eating more junk food as a result of the blood sugar drop after the initial spike." Wheat gluten binds to the mu opioid receptor in the brain (and peripherally), and leads to a "hidden" wheat addiction which actually stimulates craving for more food. Because of this, consumption of "healthy whole grain wheat" can lead to obesity very quickly, along with a myriad of other ailments. See the book, Wheat Belly, by Dr. William Davis.
This is just madness for someone like me. There is JUST NOT a concensus on anything ANYMORE. I say eat whatever you like in sensible quantity but fill up on greens and veggies.
Actually, no madness. The comment to check out "Wheat Belly" is right on track. It does get a bit deeper into the chemistry of why wheat is potentially public enemy #1, which can be tough to read through. Still, the author does a great job of laying out some really eye-opening hypothesis concerning wheat and it's connection to obesity and a myriad of other modern ailments.
Wheat belly is Fauxscience, it recommends removing gluten for many reasons, but not replacing it with any gluten alternatives such as corn or potato flower. You will lose weight and feel better because you have removed simple carbohydrates from your diet. You can easily eat wheat and be healthy if you do so in moderation like anything else.
I agree with Scott. Wheat Belly is filled with unsubstantiated claims that are merely the opinion of the author. It's just another repackaged low carb diet.
This is not rocket science. Find foods that you like to eat with a low glycemic index and follow food pyramid. Exercise and chase the girlfriend or wife around...
This web page from Harvard lists the same glycemic index for both white flour bread and whole wheat brad (71).