Stacey Frattinger, RD, CHFS, Certified Integrative Health Coach, currently resides in Sparks, NV. She owns a virtual health coaching and nutrition counseling practice, mainly focusing on one-on-one, individualized whole body wellness practices.
Simply put, the glycemic index, measures how quickly food causes our blood sugar level to rise. The glycemic index itself is not a weight loss plan, nor a specific diet, but one of the many tools used to make smarter food choices. The GI ranks food on a scale of 0 to 100, only ranking carbohydrates, as proteins and fats do not cause the same blood sugar response. Foods with a high GI are quickly absorbed and digested, causing a rapid rise in blood sugar and are typically highly processed carbohydrates and simple sugars. On the other hand, foods with a low GI, take longer to be absorbed and digested, meaning your blood sugar takes longer to rise after eating. The foods that rank the lowest on the scale are typically high in fiber, protein, and/or fat. Here are some examples to better illustrate this point: A GI diet prescribes meals primarily of foods that have low values. Examples of foods with low, middle and high GI values include the following: Low GI (1-55): Green vegetables, most fruits, kidney beans, chickpeas, lentils, bran breakfast cereals Medium GI (56-69): Sweet corn, bananas, raw pineapple, oat breakfast cereals, and multigrain, rye bread High (70 or higher): White rice, white bread and potatoes
The Glycemic Index diet is basically a system that ranks food according to how much carbohydrates will raise blood sugar (glucose) after eating. It was first developed as a tool to help people with diabetes control their blood sugar, a movement led by David Jenkins, MD, PhD. Jenkins challenged the assumption promoted by the diabetic exchange system that all simple carbohydrates caused a rapid rise in blood glucose levels and all complex carbohydrates released glucose more slowly into the blood. Now diet books based upon the GI system crowd bookstore shelves as many popular commercial diet plans are based upon the principles of the glycemic index (i.e. the Zone Diet and Sugar Busters). Today the University of Sydney, operates a GI-testing laboratory, continuing to update food lists, ranking carbohydrates. As a result, Australian supermarkets have foods labeled with their GI ratings for consumers to use.
Using the GI system to help you make healthy choices is quite easy once you have a good understanding of how carbohydrates rank on the index. There aren’t really any rules to follow. If you like to dine out, you’ll be able to do so, which will greatly impact your ability to comply. Without the structure of a specific diet plan, such as the Zone Diet or Sugar Busters, all you have to do is decide what and when to eat, and portion control is up to you. The biggest compliance issue will be handling sugar cravings (for example, choosing to eat a piece of fresh fruit instead of the candy bar).
It is difficult to estimate the potential cost of choosing to institute the GI system into your diet. Whole-grains, fruits, and vegetables are staples that should be purchased each week if you choose mainly low GI foods. These foods are generally more expensive than are highly processed foods like sugary cereals, and sweets. If you tend to purchase these products regardless of the plan you are following, you shouldn’t notice any changes in your spending.
We live in a world that makes healthy eating quite convenient, so if you are pressed for time or don’t like to spend hours in the kitchen, make sure to keep your house stocked with pre-packaged salads, steam-fresh or frozen vegetable selections, and sliced fresh or frozen fruit. This will help to ensure the ease of incorporating low GI foods into your day. Many markets, particularly natural and organic food stores, have ready-to-eat brown rice, whole grain hot cereals, and high-fiber snack products.
The index, when used as a stand-alone measure, has not raised any serious concerns related to safety thus far.
The glycemic index system, as a stand-alone measure, is highly debatable within the nutrition community. Those who fall into the “anti-GI” camp make some very valid and interesting points. Your blood sugar response to any given food choice can vary widely from day to day. Also, because we are all chemically different, not every individual will experience a predictable blood sugar response when eating carbohydrates. The systematic ranking of low versus high GI foods is highly variable from person to person.
Benefits: Despite the debate surrounding the GI system, following the measurement system can help people with diabetes fine-tune their blood-sugar response. If you are diagnosed with pre-diabetes, using the GI may help you lower your risk of progressing to full-blown disease. In addition, if you are looking to lose weight, eating a low-GI diet may help to regulate your appetite and hunger due to the blood sugar response.
Downsides: There is a wide range of GI scores based on a variety of factors, including ripeness and cooking times. As an example, the more ripe the banana is, the higher its GI value. Remember, GI index scores only indicate the blood sugar response when a carbohydrate is eaten on its own, not when they are consumed with proteins and fats. Ultimate, it's not the GI score of individual foods that should be considered, but rather GI score of an entire meal that matters.
The Bottom Line: The glycemic index can certainly be a useful tool to help you increase the nutrient density of your diet if you are looking to improve your eating habits by limiting refined and simple carbohydrates; however, if you are looking to lose weight or improve your health status, the system works best when combined with some additional kind of structure, such as food logging, a specific dietary plan, or calorie counting.