Glycemic Index. Is it the holy grail to fat loss?

Dated: 27 Aug 2009
Posted by Kevin Weiss
Categoiry: Fat Loss, Overall Fitness
0 Comments

Many people are familiar with the glycemic index (GI) but for those that are not lets start with a brief description. The glycemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels. It stands to reason that when fat loss is your ultimate goal a low GI diet is the path to the promised land and all high GI foods should be banished. Well maybe it is not that black and white.

One problem is how the GI of specific foods are determined. In a clinically controlled setting,  portions of food that contain 50g of carbohydrate are fed to people who have fasted overnight. The rise in blood sugar is measured every 15 minutes for 3 hours and then plotted on a graph. The area under the curve is measured and indexed against glucose at 100. That number is the food’s glycemic index. The higher the rise in blood sugar, the higher the glycemic index of that food. Although this makes nerds in lab coats happy, because of the controls that can be imposed, this is not a reflection of real life.  The digestion/absorption of previous meals, as well as the context of the carbohydrate food can drastically alter GI. Rarely are foods eaten in isolation and in the amounts that are seen in these tests. For example carrots, contain about 7% carbohydrate. This means you would have to eat more than 5 lbs of carrots first thing in the morning, by themselves, to get a GI rating. That’s not realistic. Also the GI of a food is different if it is cooked or raw, mashed or chopped, and more or less ripe.  Adding protein, fat or fiber to a carbohydrate further alters it GI.

If a lean, ripped physique is you goal, choosing food based on GI alone holds many pitfalls. Many high calorie foods have relatively low GI ratings. Ice cream, milk chocolate, and peanut M&M candies all have a lower GI rating than a yam.  I have designed many successful fat loss diets that included yams. I have yet to reccomend ice cream for someone seeking a ripped six pack.

Although I would like to take credit for exposing these flaws in the GI that is very far from the truth. These short coming have been known for a long time. Of course when a flaw is found with a particular system an alternative is proposed to pick up where the other fell short.  Enter the Glycemic Load Index or GL.  Next time we will see if this holds the answers to the never ending battle of the bulge. Have a great day.

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If you would like to contact me shoot me an email at kevin@kevinweiss.com

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Glycemic Index. Is it all that and a bag of carrots?

Dated: 27 Aug 2009
Posted by Kevin Weiss
Categoiry: Overall Fitness
0 Comments

Many people are familiar with the glycemic index (GI) but for those that are not lets start with a brief description. The glycemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels. It stands to reason that when fat loss is your ultimate goal a low GI diet is the path to the promised land and all high GI foods should be banished. Well maybe it is not that black and white.

One problem is how the GI of specific foods are determined. In a clinically controlled setting,  portions of food that contain 50g of carbohydrate are fed to people who have fasted overnight. The rise in blood sugar is measured every 15 minutes for 3 hours and then plotted on a graph. The area under the curve is measured and indexed against glucose at 100. That number is the food’s glycemic index. The higher the rise in blood sugar, the higher the glycemic index of that food. Although this makes nerds in lab coats happy, because of the controls that can be imposed, this is not a reflection of real life.  The digestion/absorption of previous meals, as well as the context of the carbohydrate food can drastically alter GI. Rarely are foods eaten in isolation and in the amounts that are seen in these tests. For example carrots, contain about 7% carbohydrate. This means you would have to eat more than 5 lbs of carrots first thing in the morning, by themselves, to get a GI rating. That’s not realistic. Also the GI of a food is different if it is cooked or raw, mashed or chopped, and more or less ripe.  Adding protein, fat or fiber to a carbohydrate further alters it GI.

If a lean, ripped physique is you goal, choosing food based on GI alone holds many pitfalls. Many high calorie foods have relatively low GI ratings. Ice cream, milk chocolate, and peanut M&M candies all have a lower GI rating than a yam.  I have designed many successful fat loss diets that included yams. I have yet to reccomend ice cream for someone seeking a ripped six pack.

Although I would like to take credit for exposing these flaws in the GI that is very far from the truth. These short coming have been known for a long time. Of course when a flaw is found with a particular system an alternative is proposed to pick up where the other fell short.  Enter the Glycemic Load Index or GL.  Next time we will see if this holds the answers to the never ending battle of the bulge. Have a great day.

kevin@kevinweiss.com

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