The Glycemic Index And Its Effectivenss As A Weight Loss Plan

The Glycemic Index and its Effectiveness as a Weight Loss Plan

Thomas Jefferson once said, "We rarely repent of having eaten too little." Throughout history, Americans have been obsessed with losing weight. Most new weight loss ideas promise to be the easiest and quickest ways to lose weight. Americans are eager to try these new weight loss plans in the never-ending pursuit to lose weight without putting forth any more effort than necessary and without giving up favorite foods. One such diet plan that has become increasingly popular in the wake of the low-carbohydrate craze is the low-Glycemic Index diet.

The original intent of the Glycemic Index (GI) was to aid diabetics in managing their blood sugar; however, the use of the Glycemic Index as a tool for losing weight has gained increasing attention in the wake of the low carbohydrate craze. If followed correctly, the Glycemic Index can be a useful tool for losing weight, but the same can be accomplished with a reduced calorie diet.

According to the International Food Information Council (Food Insight, 2006), the Glycemic Index (GI) was developed by a group of researchers about 20 years ago to help measure the effect that foods containing carbohydrates have on blood sugar. Carbohydrates are turned into glucose when digested which cause blood sugar levels to rise. Some foods cause the blood sugar to rise more than others. By measuring the change in blood sugar levels when certain foods are eaten compared to a control food, experts assign a number referred to as the food's Glycemic Index.

A search on the internet can result in many different sources which list the Glycemic Index values of foods. One such source is http://www.glycemicindex.com/ which offers a search of the GI Database. A search can be conducted for the GI value of a particular food or for a listing of foods within a certain GI rage. Foods with a GI over 70 are considered high, a GI under 55 is low, and foods between 56 and 69 are considered intermediate. (Home of the Glycemic Index, 2007)

Figure 1. Glycemic index values of selected foods.

Home of the Glycemic Index, 2007.

Aside from promoting weight loss and aiding in blood sugar management, the Glycemic Index offers other benefits. "Switching to eating mainly low GI carbohydrates that slowly trickle glucose into your blood stream keeps your energy levels balanced and means you will feel fuller for longer between meals." (Home of the Glycemic Index, 2007) This will result in reduced risk of heart disease, reduced cholesterol levels, and prolonged physical endurance.

This number is determined by the speed at which it breaks down in the body and releases sugar into the blood stream. Quick surges in blood sugar result in more carbohydrates being converted into fat in the body. (Kuzemchak, 2003)

Following a low-GI diet, whether for weight loss or managing blood sugar, is not as simple as it may sound. The International Food Information Council (Food Insight, 2006) reports there are many variables which help determine the GI value of a food. The ripeness, the variety of the food, how it is prepared, and the amount consumed all determine the value. The portions used for testing are standard portions and are not usually the size normally consumed by most people. The GI is also affected by the combinations of foods eaten together. A low GI food eaten with a high GI food will reduce in an intermediate GI level.

In comparing the success of the Glycemic Index when used for weight loss versus a low calorie or low fat diet, research shows those following the low-GI diet showed the same weight loss. Weight Watchers researchers, in Glycemic Index & Weight Loss (2007), reports of 20 studies comparing high-GI and low-GI diets. In these studies, which were all under six months in duration, four of the studies reported the low-GI diet to be superior and two showed the high-GI to be more successful. The remaining 14 studies showed no difference between the 2 diets.

One such study which reported no difference in the success of the low-GI diet was a year-long study, done by the U.S. Department of Agriculture-Tufts University. In this study, as explained in "Calories count more than food type" (DeNoon, 2007), one group was put on a low-GI diet and one on a high-GI diet. Both groups cut their calories by 30%. "Energy-intake measures and food diaries showed that people in both groups cheated. But at the end of a year, both groups lost the same amount of weight and the same amount of body fat." (DeNoon, 2007 para. 11)

A group of 29 adults participated in a similar year-long study with similar results. Their diets, one group on the low-GI diet and one group on the high-GI diet, were designed to cut calories by 30 %. During the first six months, the food was provided and the participants were on their own to follow their diets during the second six months. Even though they were instructed as to the study's rules, each group only cut calories by 17%. In the end, both groups lost around 10% of their weight. (Glycemic Index & Weight. (Quick Studies)(Brief article), 2007)

Another study, as reported by Karen Collins in "Glycemic index versus calorie control" (2005), was a 12-week study where two groups, one following a high-GI diet and the other a low-GI diet, were monitored for a year. The group following the low-GI diet resulted in not only the same