Glycemic Load (GL) Better Measure Than Glycemic Index (GI)
(BeWellBuzz) MD and diet expert Dr. Steven Sisskin wrote in a recent article, “excess insulin makes you fat.” As the blood is flooded with sugar/glucose, the pancreas produces loads of insulin to:
- transport glucose into cells
- stimulate glucose to fat conversion
Insulin’s job is partly to get sugar out from the blood. Whatever the cells don’t receive quickly and efficiently, the insulin turns to adipose.
The Glycemic Index (GI) rates a food based on how quickly it spikes blood sugar levels. A ranking at or below 55 is considered low, slow and good; over 70 is high.
To illustrate, a wheat tortilla ranks a GI of 30; but a fruit rollup is a whopping 99. One contains more complex nutrients, slowing absorption and release of glucose; whereas the candy immediately causes a deluge of sugar and insulin.
Eating the wrong sources of carbohydrates overtaxes the system and ignites the process leading to insulin resistance… and insulin resistance is now being linked with the major epidemics of our time including Alzheimer’s Disease, Obesity, Heart Disease and Cancer. To help resist insulin resistance, consider the Glycemic Load (GL).
GL is better than GI
Whereas the GI is a fixed number telling us how quickly a food releases glucose into the blood, the GL takes into account the amount of carbohydrates actually present in the food. This gives us a more accurate rendering of the food’s overall effect on blood sugar. The glucose may be released and absorbed quickly, but provide very little glucose overall, which doesn’t overwhelm the system.
For instance, an apple has a GI of 39; but it’s made up of a lot of water and fiber, leaving us with a small number of net carbs. Although the GI is almost 40, the GL is only 6.4. Big difference!
Illustration – Carrots
Eating lots of carrots may turn you slightly yellow or orange, but no one’s ever gotten fat off the rabbit food. Yet, if you looked at the GI alone you’d see its rating is high at 92, while its carb content is so low that the GL scores at 1. The GL is now considered a much better indicator of a food’s potential to create dangerous blood sugar spikes, bring on insulin resistance, make us fat and begin to create unhealthy.
The GL Formula
Foods with a glycemic load less than 10 are your best, healthiest, keep-you-leanest sources of carbohydrates. A GL over 20 causes the unwanted sugar and insulin spike; eat these infrequently. A glycemic load between 10 and 20 is moderate and should be eaten with some moderation.
To determine the GL of any food, multiply the food’s GI with available carbohydrate content. Then divide by 100. For example, one medium apple usually scores a GI of about 40 and contains about 16 g available (net) carbs. 40 x 16 = 640/100 = 6.4.
The reason for inventing the index and the GL formula was always to help control blood sugar levels. There are multiple lists available detailing the GI, carb content and GL for you so that you can make the best food choices to suit your needs. One extensive list is from Harvard Health Publications of Harvest Medical School.
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Sources:
Harvard Health Publications of Harvest Medical School
Fat Loss By the Numbers, Article by Dr. Steven Sisskin MD
Glycemic Load, Wikipedia
Glycemic Load, Self Nutrition Data
