Popular diets, such as the South Beach, Zone and Sugar Busters plans, use the glycemic index to help dieters select carbohydrates that have little impact on blood sugar. The glycemic index, or GI, measures the potential a food has to raise glucose levels. The lower the score on the GI, the less impact that food will have on your blood sugar. Keeping your blood sugar stable can promote weight loss by reducing food cravings and helping you feel full longer.
The Benefits of the Glycemic Index
Originally developed as a tool for people with diabetes, to help control blood sugar, the glycemic index quickly became the basis for many different diets. Choosing foods that score below 55 on the glycemic index can stabilize glucose, lower cholesterol and reduce your risk of obesity, Type 2 diabetes and heart disease. Low-GI foods are often high in fiber, which slows digestion and the conversion of food into glucose. Foods high on the GI raise glucose levels quickly, which can result in a "sugar crash" and cravings for more sugar in just a few short hours.
Pros and Cons of a GI Diet
Most GI-based diets don't require calorie counting or portion control -- if you're choosing the "right" carbohydrates, you'll lose weight because your blood sugar will be stabilized. Low-GI diets are not necessarily low-carb, although many low-carb diets suggest choosing low-GI carbs such as vegetables, fruits and whole grains. Foods rich in carbohydrates, such as legumes, may still be low on the glycemic index because of their high fiber content. You'll still need to make healthy choices, even when using the GI as a guideline. Although fiber slows digestion -- so does fat. High-fat foods such as chocolate, can score low on the GI. The glycemic index can't be your only tool for choosing healthy foods.
The GI and the South Beach Diet
The South Beach Diet is divided into three phases. The first phase restricts carbs; allowable carbs are low-GI foods such as green vegetables, lean proteins and healthy fats. Restricting high-GI foods stabilizes blood sugar and helps reduce cravings -- one of the reasons most diets fail. The South Beach Diet claims to be a "lifestyle" more than a diet. Phases two and three allow more carbohydrates, but they must still be low on the glycemic index. Phase two allows legumes, whole grains and brown rice -- all high in fiber to help you feel satisfied sooner and stay full longer -- which may lead to eating fewer calories and weight loss.
The GI and the Pritikin Diet
In contrast to many low-carb diets, the Pritikin plan is a high-carb/low-fat diet that encourages people to choose low-GI foods. The Pritikin plan includes at least five servings of whole grains, four servings of low-GI vegetables, three servings of fruits, two servings of non-fat dairy and one serving of lean protein each day. Protein and fat are extremely limited -- less than 10 percent of calories come from fat; the diet relies on the fiber found in low-GI foods to stave off hunger. Many find this low-calorie program difficult to live with, but results are proven and can be dramatic. The Pritikin plan may lower blood pressure and reverse heart disease and Type 2 diabetes.
