When determining the foods to add into our daily diet (especially our carbohydrate choices) it is important to consider the glycemic load. Glycemic load is the single greatest determining factor on how much and when we should consume the carbs we eat. Read on below for a total introduction to glycemic load. If you haven’t yet read part 1 or part 2 on carbohydrates, then I recommend starting there, and then coming back to this article later on.
Glycemic load is the combination of two factors: a food’s glycemic index, and a standardized portion of 100 grams of the food. This means that glycemic load is determined by the glycemic index of a food COMBINED with the amount of carbs in a 100 gram portion: this creates a much more accurate measure of how a food will affect your blood sugar than portion size or GI alone. Glycemic Load = GI x net carbs/100. Since glucose is used as the standard these equations are divided by 100 to find glycemic load.
A GL of 20 or higher is considered high, 11-19 is considered medium, and 10 or less is considered low. I do not actually take the time to measure out the glycemic load in every meal I eat, but the point of this article- and series- is to help you actually understand what effects the food you eat will produce in your own body so you can plan accordingly.
The main idea of this article is that you understand that a small portion of a high GI carbohydrate will produce a response equivalent to a medium or large serving of a low GI carbohydrate. This is important for several reasons; when you are trying to lose weight- no one likes to starve- if you understand that 3/4 cup of brown rice will have the same effect as 1/2 cup of white rice, you can eat more and still maintain or lose weight. The reason this occurs is because of the hormone insulin I mentioned early (remember high blood sugar levels require higher insulin levels and insulin make you store carbs as fat). Less insulin is produced with a lower GL food, and that means less fat storage. Following the principles of eating low Glycemic load foods, will allow you to eat more food and still lose or maintain weight. The key here is that both portion size and glycemic index affect your blood sugar.
Take a look at the nutrition labels on your food and you can easily find out how many carbohydrates are present in the food. On the label it should list protein, fats, and carbohydrates, present in grams, in one serving of the food. The best way to gauge how many carbohydrates are actually in a serving, is to find the total carbs in a serving and then subtract fiber: this will give you the net carbs present (the carbs that will actually affect blood sugar). For example, if a food has 25 grams of carbohydrates in a 1/2 cup serving and 9 grams of fiber then you will subtract 9 from 25 to get 16 grams of total net (or impact) carbs. If this food happens to be a low GI food then it is an excellent choice for a carbohydrate source. With some practice you’ll be able to remember what foods are high or low GI and you’ll learn roughly how many impact carbs a food has. Without much effort, you can look at a label, and look for the amount of carbs, sugar, and fiber present in a food; high fiber low sugar foods are usually good, while high sugar low fiber foods will have a much higher Glycemic load and should be avoided.
Glycemic Load effectively combats the main problems with the Glycemic Index system. For instance,white and wheat bread are high glycemic index foods, however the amount of net carbs present in a serving of whole wheat bread are much lower than white bread, (due to higher fiber content) so the glycemic load ends up being less in the whole wheat bread. An excellent resource to find glycemic loads, along with other nutrition data, can be found here: http://nutritiondata.self.com. They have an extensive collection of foods with in depth nutrition data and they always show glycemic load as well. Start out by looking up the foods you eat and looking around, after a while you will have a good understanding of which foods have favorable glycemic loads: then you can make better choices based off that knowledge. Remember, if you are looking to lose or maintain weight, always avoid processed and refined carbohydrates: white bread, white rice, white potatoes, sugars, sweets, and white pasta are some of the biggest enemies of someone looking to loose wight or maintain their blood sugar levels at a stable level.