It seems like more and more people are turning to gluten-free or wheat-free products as a panacea, regardless of whether or not the avoidance of gluten or wheat is warranted. There are a number of books and advocates for such a diet; the primary one being Wheat Belly. Not having read the book myself (although I suppose I will have to remedy this at some point – I just don’t want to actually pay money to do so) I can’t comment on it directly. My current approach to dealing with zealous converts is to state that consuming too much of any one type of food is not a balanced diet and that most of us could benefit from consuming a wider variety of grains.
Anyway… A fan of the book enthusiastically told me that whole wheat bread causes a greater spike in blood sugar than a chocolate bar does. This did nothing to convince me of the evils of wheat. However, I can see how it might help to persuade someone who doesn’t fully understand the concept of the glycemic index (GI) and glycemic load (GL).
The GI is “the blood glucose response of a given food compared to a standard (typically; glucose or white bread).” It’s how rapidly your blood sugar will increase when you consume a particular food (containing 50 g of carbohydrate), as compared to a simple carbohydrate which is easiest for your body to convert into sugar. A GI of 55 or less is considered to be low, 56-69 is medium, and 70 and above is high. However, GI only considered the form of carbohydrate in a food, it failed to take into account the fact that people may not (and often do not) consume foods in quantities that will provide them with 50 g of carbohydrate. Thus, GL was developed. The GL is “the amount of carbohydrate in a food multiplied by the glycemic index of that carbohydrate. The result is then divided by 100”. The GL is a percentage; the lower the number the less overall impact the food actually has on your blood sugar. Less than 10 is low GL, 11-19 is intermediate, and more than 20 is high.
Let’s compare that whole wheat bread and chocolate bar. One slice of whole wheat bread has an average GI of 69 and a GL of 9. One ounce of chocolate has a GI of 49 and a GL of 9. Whole wheat flour is finely ground so it’s rapidly converted into blood glucose. Even though chocolate has a lower GI than bread it actually has the same GL depending on the quantity consumed. Clearly, there is no reason to demonize bread based on this data alone. GI and GL are just a couple of small tools in food selection. Different sources will provide you with different figures for the same foods. In addition, the GL for one variety of whole wheat bread may vary significantly from another. The other foods you consume at a meal will all provide different GLs so unless you’re eating plain bread or bread with just jam on it, knowing the GL of your bread isn’t all that useful. Also, gluten-free and wheat-free breads have similar GI and GL profiles to whole wheat bread rendering a switch to these products for this reason alone unnecessary.
If you’re considering going wheat- or gluten-free because it’s the trendy thing right now you might want to reconsider. Unhealthy gluten-free products are a rapidly growing industry. Instead, consider consuming a wider variety of grains and try to consume more grains in as close to their natural state as possible. Some to try: wheat berries, buckwheat, wild rice, millet, groats, barley, etc.
*All figures taken from Perspectives in Nutrition by Gordon Wardlaw and Jeffrey Hampl (no APA or MLA here. Take that university education!)