You’ve probably heard about “low-GI” foods, and how they can benefit your health. But what does “GI” mean, anyway? And why does it matter? Today, we get to the bottom of the Glycemic Index – literally! – and help you understand what it means for your health.
The Glycemic Index (GI) is a scale that nutritionists and other health professionals use to measure glucose (blood sugar) levels. It ranks carbohydrate rich foods by how much they raise glucose levels, on a scale of 1-100. Anything under 55 is generally considered to be a low GI food.
The GI measures the speed at which your digestive system is able to metabolize food to form glucose, which then enters the blood stream to nourish and energize your entire body. The GI was originally developed to assist diabetics with the control of their blood glucose levels. It has also become adopted as a part of numerous popular weight loss diets such as the South Beach Diet, Nutrisystem and The Zone.
So… what does this mean for you and your diet and exercise routine?
The more highly ranked a food is on the GI, the more quickly the food is turned into glucose, leading to a rapid rise in blood sugar – and a subsequent blood-sugar crash afterwards, which makes you feel awful. Foods ranked lower on the GI take longer for your body to break down and process, leading to a slow, steady rise in blood sugar. The primary goal of monitoring the GI of the foods you eat is to find food that are nourishing to your body for longer.
The goal of a “low-GI diet” is to eat unprocessed, unrefined carbohydrates along with healthy proteins and fats to promote slower digestion and regulate your blood sugar, giving you more energy in a more steady way.
In general, foods like white bread, white rice, processed breakfast cereals, potatoes and fruit juices rank highly on the GI, while whole foods (which contain no added ingredients) rank much lower. Foods with a lower GI ranking are digested at a slower rate, and so it takes you longer to feel hungry again after eating them. Foods that rank lower on the GI scale also help maintain more constant rates of glucose in the body, which is beneficial for people who have conditions such as diabetes or hypoglycemia.
There are numerous advantages of eating more low GI foods. According to the Canadian Diabetes Association, eating foods with a low GI rating may help to control blood glucose levels, cholesterol levels, and appetite, and to decrease your risk of heart disease and type 2 diabetes. A recent study published in the Journal of the American Medical Association found that obese patients who adopted low-glycemic index diets burned more calories per day than patients who ate a low-fat diets, even when they consumed the same number of calories throughout the day.
There has been some criticism of the GI: it does not measure caloric intake of food or the time of day that a food is eaten, which can also affect your hunger levels. As well, many packaged foods do not have specific GI rankings. However, most fresh, healthy, unprocessed foods rank low on the glycemic index – such as vegetables, fruits, whole grains and dairy products. So if you’re eating a healthy diet already, chances are you’re already eating low GI foods without even knowing it!
If you need a bit of help figuring out what some lower-GI foods are, here’s our list of ten great low GI Foods:
1. Spinach – our favourite dark, leafy green! It’s full of fiber, iron, protein and many essential vitamins.
2. Stone-ground whole wheat, rye, pumpernickel or sourdough breads – skip breads made with white flour and sugar.
3. Beans of all kinds are great – green beans, soya, kidney, haricot, black-eyed, and kidney. Pick ones that are fresh or dried (and then rehydrated), over canned if you can.
4. All varieties of peppers rank low on the GI as well, so pick your favourite and add them to salads and stir-frys, put in sauces, or eat them raw as a snack.
5. Cherries are always a treat and they rank only a 22 on the GI scale!
6. When making pasta, choose whole wheat or protein-enriched pasta over the processed white variety.
7. Pick real oatmeal or porridge (the stove-top variety, or the even the instant type is okay) instead of commercial breakfast cereals.
8. Stevia is a natural sweetener that can be used in place of sugar in your coffee or tea. It is sweeter than regular sugar, has zero-caloric value and ranks as a 0 on the GI scale.
9. Unsweetened soy milk ranks lower on the GI than dairy milk, but fat-free and skim milk are also considered to be low on the GI scale.
10. Nuts of all kinds are great for a boost in your energy: they’re full of healthy fats and they generally rank low on the GI. Almonds, peanuts, walnuts and brazil nuts are great choices. But remember that nuts are very calorie dense, so eat them in moderation.
If you’re ever curious about how certain foods rank on the GI, you can always check out the official GI Rankings by the University of Sydney.
Do you pay attention to the GI ranking of the foods you eat, why or why not? If you’ve had successes (or mixed results) with using the GI, we’d love to hear your experiences – please leave us a comment below.