Why You Should Pay Closer Attention to the Glycemic Index

The relevance — good and bad — of incorporating carbs into our diet is a constant source of confusion for most people who are looking to lead a healthier lifestyle. A primary source of this confusion is the glycemic index. For those of you out there who are unfamiliar with this particular form of measurement, the glycemic index is a numerical chart that ranks carbs based on how quickly they are converted to glucose in the human body. People who are at risk for diabetes, or people who are attempting to be be more conscientious of their weight often utilize this index as a way to regulate how many net carbs they consume throughout the day. It is a great tool to become familiar with, so take a look below to learn more!

What it is:

This numerical index uses a scale that ranges from 0 to 100, where the higher the number of a given food, the more rapid the increase in an individual's blood sugar. Pure glucose serves as the reference point, with a glycemic index of 100. One of the main purposes of this scale is to show that the food we consume is not as straightforward as simple sugars, which digest quickly, and complex carbohydrates, which take longer for the body to process. Essentially, the premise of the index is that foods that are more processed, such as white bread or white rice, have a higher number, whereas more natural foods like whole wheat bread and brown rice rank much lower, and are therefore healthier. According to Self: Nutrition Data, the intent of the glycemic index is to reduce the amount of insulin-related problems by identifying and avoiding foods that have a magnified effect on the blood sugar.

Why it's important:

Knowing and understanding the glycemic index is a great way to balance out your diet, as it encourages us to consume foods that tend to be healthier and more easily digestible within the body. We function at our best when our blood sugar is at a constant level with only minor fluctuations. If our blood sugar dips too low, we lose all our energy and become tired and lethargic. On the other end of the spectrum, if we consume too much sugar and our blood sugar spikes, the brain signals the pancreas and it secretes more insulin than is necessary. All of that excess sugar that is released is then stored as fat. Also, if too much glucose is consumed, and extra insulin is released, the blood sugar once again plummets back down, and we lose our energy. While high levels of glucose in our system can lead to a short-lived boost of energy and activity, it passes quickly and we are once again stuck within the confines of fatigue. Maintaining a well-balanced system is essential to keeping our activity levels up, and that extra poundage down.

The exceptions:

Avoiding food that is high on the glycemic index is generally a good idea, but there are definitely a couple exceptions to the rule! First, if we only eat foods that are lower on the index, our bodies will eventually grow accustomed to the diet and our metabolic rate will slow down. To keep that metabolism revved and ready to burn through those calories, it's okay to occasionally indulge in some high-number foods. Keeping your metabolism guessing will help stabilize your system, so the odd Girl Scout cookie is not the end of the world! Also, many professionals recommend that you give yourself a little boost after working out. A rapid increase in sugar after exercising actually helps transport glucose into muscle cells and promotes damage repair. You have probably seen athletes chugging gatorade or other sport's drinks after the big game, right? Well, that extra sugar will go a long way in promoting a muscle growth.

Problems with the glycemic index:


Like every diet out there, there are some underlying problems that experts have found with the glycemic index:

  • Not all foods have a ranking. Only about 5% of foods actually possess a number, and it can be a real challenge to estimate a ranking for all of the other foods out there.
  • The index does not take quantity into account. Sure, peanuts may have a low GI number, but if you eat a cup of them, that's almost 1,000 calories, and more than the average daily fat recommendations! Also, foods like candy bars tend to rank pretty high on the index, but a piece of dark chocolate by anyone else's standards is typically considered a perfectly healthy treat.
  • Single values for foods are hardly precise, and the deviations can be pretty extreme. For instance, many professionals claim that the GI number for fruit increases as it ripens, but by how much is unpredictable.
  • Food preparation affects the GI number. Any kind of blending, baking, sautéing, and cooking changes the basic raw essence of food, which typically causes the GI number to rise. However, there are no guidelines to measure just how much the number increases.
  • Individuals digest at different rates. Obviously, one person's digestive system is uniquely different from everyone else's, and the glycemic index does not account for those variations.
  • Total dependence on the glycemic index may lead to an unhealthy diet. Think back to the peanut example: Sure, the peanut has a low GI number, but the calorie count and fat content is sky-high. People who depend solely on the glycemic index often find that they are consuming too much fat and calories.

A basic understanding of the glycemic index can go a long way in helping you cut out the unhealthy foods in your diet. If you want to know where to begin educating yourself, check out our sources here: Self: Nutrition Data, Brigham and Women's Hospital, The World's Healthiest Foods.