Glycemic Index and Glycemic Load of foods: Which one should you follow?
If you make choices only based on the Glycemic Index of foods you'll find that foods that have always been considered healthy, such as carrots and strawberries, all of a sudden, are at the top of the GI list with a high GI value.
But no one ever gained weight from eating carrots, nor do carrots, in
the real world, raise blood sugar. What is the Glycemic Index missing?
Some scientists and nutritionists have come to prefer another version of the Glycemic Index known as Glycemic Load (GL).
The Glycemic Index takes into account how much a 50g-serving of a carbohydrate raises blood sugar levels.
The Glycemic Load takes into account the amount of carbohydrate in a typical serving of the food instead of however much you'd need to eat to get 50 g.
A GL of less than 10 is low, a GL of 11 to 19 is medium and of 20 or more is higher.
When it comes to choosing between the Glycemic Index and Glycemic Load, following the GL of a food makes more sense, as most fruits and vegetables contain a lot of water, so there's not much room in them for carbohydrate.
Bread, on the other hand, is crammed with carbohydrate. You get 50 g. by eating just one slice.
Watermelon has a GI value of 76 but a GL value of 4. Why the difference? You'd need to eat about 6 cups of watermelon to consume 50 g. of carbohydrate, whereas a more typical serving is about 3/4 of a cup. Hence the raise in blood sugar would be really insignificant. A 4 oz. portion of watermelon has a GL of 4. By contrast, just one bagel contains 55 g. of carbohydrate and a GL of 20.
Another example is beetroot. Although the carbohydrate in beetroot has a high GI, there isn't lots of it, so a typical serving of cooked beetroot has a GL that is relatively low, about 5. Compare this with a portion of sticky white rice that has a GL of 30.
Foods that are mostly water (e.g. apple, or watermelon), fiber (e.g beetroot or carrot) or air (e.g. popcorn) will not cause a steep rise in your blood sugar even if their GI is high as long as you eat a moderate portion.
The lower the GL of your diet, the more likely you are to keep your weight under control and stay free of chronic disease.
For a list of foods with their GI and GL values follow the link.
The Glycemic Index and the Glycemic Load values are just a guide to help you choose foods that don't cause a huge spike in your blood sugar levels.
But what if you don't like keeping track of all those numbers? Is there an easier way of keeping your blood sugar levels in shape? Yes, there is. Follow these simple rules and you can't really go wrong:
1) Don't worry about fruits and vegetables too much (with a few exceptions) - Most produce contains only modest amounts of carbohydrates per serving. Also, most of the sugar in fruit is fructose, which doesn't cause blood sugar to rise. This is because fructose must be changed to glucose in the liver before being absorbed in the bloodstream, hence the slow rise in blood sugar.
2) Eat fewer root vegetables - Starchy root vegetables contain more glucose than pure sugar, so they cause a rapid rise in blood sugar levels, like potatoes for example. But there's a few exceptions: carrots and sweet potatoes contain soluble fiber, which lowers their GI.
3) Choose your other starches wisely - Most people don't like giving up bread, but how about choosing a better variety? Most white bread has a high GI (except sourdough, which has a high acid content that slows digestion). Look for whole grain breads, not 'whole wheat' breads (which are essentially the same as white breads). Brown rice has a lower GI value than white rice and pasta has a even lower GI than rice. Eat whole grain breakfast cereals such as porridge or muesli.
4) Eat more fiber - The longer it takes for a food to be digested the slower is the rise in blood sugar levels and high-fiber foods definitely take longer to be digested. That's why oats, barley, apples and some berries, and legumes tend to have low GI values.
5) Avoid sugary foods - Some might argue that soft drinks and candy only have a moderately high GI value, as sugar digests more slowly than pure glucose. But don't forget that sugary foods provide only empty calories and little else. This is one case when the glycemic index of foods is not a perfect guide - common sense has to be your guide.
6) Eat some protein at every meal - Proteins lower the GL of a meal and help curb hunger, making weight loss easier. Make sure you choose lean protein.
7) Add some acidic foods to your meal - It takes just a tablespoon of vinegar per serving to substantially lower the GL of a meal.
8) Eat smaller portions - Even when you eat a low GL diet, calories count, so cut down not only on carb-rich foods but all foods.
9) Buy more natural foods rather than processed and refined foods - Foods that come out of a packet tend to have a high GI whereas natural foods tend to have a much lower GI.
These simple rules will allow you to follow the principles of the glycemic index and glycemic load quite well.
But if you do want to know the glycemic index and glycemic load values of foods click on Next or go to the Whole Grain Foods main page to choose your next topic.