Question of the Week

December 1, 2008


The amount of carbohydrates found in one serving of of any packaged food is found on its nutrition label.

"Carbohydrates are found in a wide array of foods—bread, beans, milk, popcorn, potatoes, cookies, spaghetti, soft drinks, corn, and cherry pie. They also come in a variety of forms. The most common and abundant forms are sugars, fibers, and starches. The basic building block of every carbohydrate is a sugar molecule, a simple union of carbon, hydrogen, and oxygen. Starches and fibers are essentially chains of sugar molecules. Some contain hundreds of sugars. Some chains are straight, others branch wildly."

Because not all carbohydrates are created equal, just knowing how many grams of carbohydrates are in a food only tells part of the story.

"In the past, carbohydrates were classified as simple or complex based on the number of simple sugars in the molecule. Carbohydrates composed of one or two simple sugars like fructose or sucrose (table sugar) were labeled simple, while starchy foods were labeled complex because starch is composed of long chains of the simple sugar, glucose. Advice to eat less simple and more complex carbohydrates was based on the assumption that consuming starchy foods would lead to smaller increases in blood glucose than sugary foods. This assumption turned out to be too simplistic since the blood glucose (glycemic) response to 'complex' carbohydrates has been found to vary considerably. A more accurate indicator of the relative glycemic response to dietary carbohydrates is the glycemic index."

What the food is tells only part of the story. How the body responds to that food is what matters.

"Researchers have spent years debating what makes blood glucose levels too high. Potential culprits have included sugar, carbohydrates in general, simple carbs, starches, and more. The glycemic index is one attempt to measure each individual food's effect on blood glucose levels. ... If you're trying to lose weight, calories count more than the types of food in your diet, a U.S. Department of Agriculture–Tufts University study shows. The study shows that after a year, overweight people on a low-carb low-glycemic-index diet lost just as much weight -- 8% of their original weight -- as people on a reduced-fat, high-glycemic-index diet. ... What researchers have learned is that high glycemic index foods generally make blood glucose levels higher."

Generally. Just as the "simple" verses "complex" carbohydrate classification was too simplistic, even the glycemic index is not completely black and white.

"The glycemic index of a food isn't a set number. University of Toronto scientists found that the value can vary by 23 percent to 54 percent from person to person. What's more, it can also differ within the same person. Scientists at Syracuse University discovered that a single weight-training session reduces the effect of a high-sugar drink on blood glucose by 15 percent for 12 hours after an intense workout. Exercise uses the glucose stored in your muscles. And to replenish those stores after a workout, your body starts shuttling more of the glucose from your bloodstream to your muscles where it's packed away for future use. This helps reduce blood-glucose levels quickly, even after a high-sugar meal. ... This is also why the best time to eat fast-absorbing carbs is just before, during, and right after your workout."

While these variances may make figuring out what is best for each person a little more complicated, people can use this information to their advantage when trying to perform at their best.

"For non-diabetics, there are times when a rapid increase in blood sugar (and the corresponding increase in insulin) may be desirable. For example, after strenuous physical activity, insulin also helps move glucose into muscle cells, where it aids tissue repair. Because of this, some coaches and physical trainers recommend high-GI foods (such as sports drinks) immediately after exercise to speed recovery. Also, it's not Glycemic Index alone that leads to the increase in blood sugar. Equally important is the amount of the food that you consume. ... Although most candy has a relatively high Glycemic Index, eating a single piece of candy will result in a relatively small glycemic response. Why? Well, simply because your body's glycemic response is dependent on both the type AND the amount of carbohydrate consumed."

How many grams of carbohydrates are consumed, when those carbohydrates are consumed, and what type of carbohydrates they are all make a difference. This may seem too confusing to even bother to try and figure out, but there are some basic guidelines. As mentioned above, there are times when it is better to eat those carbs. Additionally, foods that have a haigher ratios of proteins and fats to carbohydrates tend to have less of an immediate impact of on sugar levels in the blood.

"High glycemic index foods include many carbohydrates such as these: Bread, Pasta, Rice, Cereal, Baked goods. Low glycemic index foods generally have less of an impact on blood glucose levels. People who eat a lot of low glycemic index foods tend to have lower total body fat levels. Low glycemic index foods include these: Fruits, Vegetables, Whole grains, Legumes."

Questions of the Week:
What do you need to know about how carbohydrates affect your body? How can different carbohydrates affect your body differently? How can you know how the foods you are eating will affect your blood sugar levels, and when is the best time to have that treat you might be craving? How can you use this information to your advantage so that you can perform at your best and improve your overall health?

Please email me with any ideas or suggestions.
Note: Due to increasing amounts of SPAM sent to this account, please include "QOW" in the subject line when sending me email.

I look forward to reading what you have to say.

Health Community Coordinator
Access Excellence @ the National Health Museum

Request Question of the Week by email 
QoW Archives: 9/2002 - 8/2003 9/2003 - 8/2004 9/2004 - 8/2005 9/2005 - 8/2006 9/2006 - present

Custom Search on the AE Site