Human Petroleum

Carbohydrates, however, are a key part of healthy nutrition. Like any other food, there are 'good' and 'bad' carbohydrates.

Like protein, carbohydrates are molecules used by the body for various functions. They contain carbon, hydrogen, and oxygen. Unlike protein, carbohydrates do not contain any nitrogen. The popular way to group carbohydrates used to be simple sugars (sucrose, fructose, glucose, etc) and complex carbohydrates (any carbohydrate composed of multiple sugar molecules bonded together). The belief was that simple carbohydrates are bad, while complex carbohydrates are good.

This belief has turned out to be false. All carbohydrates, whether simple sugars or complex starches, are broken down by the digestive system and absorbed into the bloodstream as simple sugars. Regardless of whether the carbohydrate you eat comes from table sugar or a bowl of salad, most of it ends up as glucose in the bloodstream. Fiber is the exception, because it is a type of carbohydrate that the body is not able to breakdown, and therefore it passes through the digestive system without providing calories to the body.

The glycemic index (GI) changed the way carbohydrates are classified. The index has been around for decades, but only recently have nutritionists began to consider the GI of carbohydrates when deciding what is good or bad. The glycemic index measures how quickly blood sugar levels rise after eating a specific quantity of food. This index uncovered that complex carbohydrates like maltodextrin (used to sweeten many foods and shakes) and potato are digested very rapidly and cause extreme rises in blood sugar levels, with some simple carbohydrates such as fructose and agate nectar are digested more slowly. Therefore, many simple carbohydrates are better choices than complex carbohydrates!

There are many reasons why carbohydrates are digested at different rates. The presence of proteins, fats, and fibers in a meal can slow overall digestion. Certain fruits such as bananas convert starches to sugars as they ripen. Fresh bananas will have less of an impact on blood sugar than ripe bananas. Enzymes in the body also readily break down certain types of starches - for example, the starches in potatoes are broken down to simple sugars in the mouth even before they pass into the gut. Most heavily processed foods are also broken down, stripped of fiber and other nutrients and are therefore easier for the body to quickly digest.

Many diets have been formed around the concept of the glycemic index. Low GI foods are digested more slowly and impact blood sugar less severely. These foods are ideal for diabetics who must regulate their blood sugar levels. Many studies suggest that low GI diets may actually result in greater fat loss compared to other diets with the same amount of calories that are composed of higher GI foods. The glycemic index, however, does not paint the full picture.

Carrots are high on the glycemic index. Consuming carrots, however, does not cause blood sugar to rise significantly or quickly. The reason is that while the carbohydrates in carrots are quickly ingested by the body, there are only a few grams of these carbohydrates in a typical serving. In other words, it would require a large quantity of carrots to get enough carbohydrate in order to have a detrimental impact on blood sugar.

To address this discrepancy, the glycemic load (GL) was introduced. Glycemic load refers to the amount of carbohydrate in a standard serving of food. Food with heavy starches like potatoes have a high GL, while foods loaded with fiber, nutrients, and water like carrots have a relatively low GL.

The gylcemic index is rated on a scale from 0 to 100, where 100 is the rate at which pure glucose enters the bloodstream. A food scoring 50 will raise blood sugar levels approximately half as much as consuming pure glucose. Some foods are actually ingested more quickly and will have a score higher than 100. Foods with a score of 55 or less are considered low on the glycemic index. The glycemic load is computed by comparing the amount of actual carbohydrate in a food to the serving size. Foods with a score of 10 or less are considered low. Here is a list of some sample foods and their glycemic scores:



There are definite patterns to take note of. Raw fruit has a lower GI and GL than juices. White bread, which is highly processed and stripped of fiber, has a higher GI and GL than whole or multi-grain bread (in most cases, some processed whole wheat breads are have a high GI but a lower GL due to the extra fiber). Whole grain cereals like porridge and pearled barley have a lower GI and GL than processed cereals. Brown and wild rice have more fiber and therefore a lower GI than white rice. Most fruits have a low GI, but even fruits such as watermelon with a high GI have a low GL.

Carbohydrates are important because they are the body's preferred source of fuel. They replenish the muscle's internal stores of fuel called glycogen, help the liver regulate appropriate blood sugar levels, and are required by vital organs for the body to function. Unprocessed sources of carbohydrates such as fruits, vegetables, and whole grains also supply the body with vitamins, minerals, fiber, and special chemicals found in plants known as phytochemicals. Studies suggest phytochemicals may improve overall health by helping the body protect itself against disease.

Don't throw carbohydrates out. In fact, you don't even have to worry about whether the carbohydrates are complex or where they fall on specialized indexes like the glycemic index and glycemic load. Instead, focus on quality, whole, unprocessed carbohydrates. Get the bulk of your 'carb calories' from fresh fruits, vegetables, and whole grains. You want your vehicle to run on the best fuel possible, so be sure to give your body the best human petroleum available: quality carbohydrates.