A low glycemic index diet plan focuses on how many and what kind of carbohydrates you eat and how you combine them with other foods. All these things determine a meal's impact on your blood-sugar level.
The glycemic index itself measures how quickly carbohydrates enter your bloodstream. The glycemic load (GL) measures both the quantity and quality of the carbs.
Understanding the Low GI Diet
Although you may lose weight while following one, weight loss isn't the primary purpose of a low-GI diet plan. This diet is meant instead to control sudden spikes in blood-sugar levels. Maintaining your blood sugar within a narrow range is critical for diabetes and cardiovascular disease prevention and control. Low-GI foods fall below 55, medium-GI foods below 69, and high-GI foods are over 80.
A food's glycemic load measures the insulin demand it places on your system. It's a reflection of both the amount and quality of carbohydrates in a food. Whole grains, for example, have more fiber and nutrients than refined ones, and so have a lower glycemic load.
Low-GL foods are under 10; medium-GL, under 20; and high-GL, over 20. In a 2006 presentation to the American Diabetes Association, dietician Johanna Burani recommended a total daily GL score of under 120.
Calculate a food's glycemic load by multiplying its GI number and the amount of carbs it contains.
Putting the Plan into Practice
The quickest way to adopt a low-GI diet plan is to substitute low-GI foods for the high-GI foods you're currently eating. Diabetes sufferer and journalist David Mendosa compiled a table based on 2002 research done at the University of Sydney's Human Nutrition Unit. It contains the GI and GL values of nearly 2,500 foods from around the world. For example, white enriched bread with a GI of 72 per serving is not as good a choice as a whole-grain English muffin at 45. The whole grains have digestion-slowing fiber minimizing the muffin's effects on your blood sugar.
The University of Sydney team's recommendations include: Eating whole oat, bran, or barley breakfast cereals; replacing potatoes with veggies and sugary desserts with fruit; switching to sourdough, whole grain and stone-ground breads; snacking on salads with vinaigrette dressing; choosing basmati over white rice; and including pasta or noodles in your meals.
Combining Foods
Following a low-GI diet plan does not mean giving up high-GI foods forever. It simply means thinking about what you can eat with them to avoid a blood-sugar spike. Combining a high-GI and several low-GI foods at a meal will reduce the impact of the high. The trick is to learn to eat "balanced meals," with both healthy nutritional content and GI numbers in the low to moderate range.
But simply keeping your glycemic-load numbers low doesn't necessarily mean you're following a healthy low-GI diet. It's easy to have a total daily GL of under 120 if you eat lots of proteins and fats, and skimp on the carbs.
Doing that, however, will boost your fat and calorie intake while depriving you of the vitamins, minerals, fiber, and phytonutrients in low GI fruits, vegetables, and whole grains.
Things to Consider
Cooking your food swells its starch molecules, softening it and raising its GI number. A serving of spaghetti cooked to the al dente stage between 10 and 15 minutes, for example, has a 44 GI number. Cooking it for 20 minutes raises it to a 64 GI number. All GI numbers are based on specific portion sizes. Eating more of a low-GI food will work against your blood sugar-regulating and weight loss efforts.
