Why Glycemic Index Charts Are Not What You Think They Are

There are plenty people talking about glycemic index when it comes to select foods or creating a meal plan for a specific diet.

I see too many people falling for the same outdated information coming from general nutrition forums, blogs or certain bodybuilders that are still spreading the same old dogma.

The same people that are basing their judgement of carbohydrate foods when it comes to their glycemic index, don’t really have a proper nutritional background or stay up to date by reading research studies.

I mean, even if you don’t know to read research studies and evaluate the end results for yourself, there are still some quality people out there, trying to do their best to present actual evidence but the same people are not so good at spreading the good information around.

It’s understandable why even this subject is still debated and the truth is not known by many people.

The answer is mainly because everybody’s interested in getting the upper hand when it comes to squeezing every variable that can affect health or body composition in a positive way.

What Is The Glycemic Index

Let’s take a look at a normal glycemic index chart:

glycemic index chart

The glycemic index is properly defined as the ability of a certain food to raise your blood sugar (speaking of glucose here).

The fact is that it’s been demonstrated that glucose’s general rate of entrance in your blood circulation is not the only important determinant of GI because there’s another variable in stake called the rate of glucose disappearance from systemic circulation. 

They demonstrated that the low GI of a bran cereal was noted like that because after ingestion, there was a quicker glucose exit from circulation due to a rapid surge of insulin which cleared it faster.

Doomed From Start

The flaw lies in how it was created:

It was created by testing certain isolated foods (bread, milk, etc.) by giving them to people after an overnight fasted state.

Everything’s good until here but what happens if you try to test isolated foods on a person that already ate something before the test and there’s food digesting in their system?

Probably, the GI of the isolated food will come a lot lower so that’s why the GI is flawed from start.

Variables like fiber, protein intake, fat intake, PH, heat and many other elements can raise or lower the glycemic response.

All these variables render it useless for a normal person.

The Satiety Factor Vs Glycemic Index

The thing is that in general, foods considered as having a low GI are thought to increase satiety and foods that were classified as high GI are thought to provide little to none satiety.

Again, the truth is nowhere near that because a study showed that foods presumably high in GI like bread, potato, rice, were the ones that actually delayed the onset of hunger with the potato having the biggest influence in reducing overall hunger and increasing satiety.

Proof That It Is Flawed

Because most people eating foods based on their glycemic index are mainly interested in foods being on the lower side, the truth is that some foods, even if they have low GI, they can raise insulin levels the same as a food considered having a high GI.

For example, milk and yogurt which should have a low GI of ~15-35, in fact have a high insulin index.

White bread and baked beans should have a low GI, but in fact the real GI is over 120 (huge!).

Speaking of foods that are fatter, in theory, they should have a lower GI but in reality, foods like fries and doughnuts are quite high in GI.

The theory behind this increase in GI is probably because of their saturated fat content.

Some foods can also have a synergistic response when combined and this is true in the case of combining a high protein food (which should lower the GI but not true), with a high carbohydrate food.

Cannon & Nutall combined a glucose solution with cottage cheese and these two foods raised insulin levels way over what they should be raising it when eaten separately. 

These examples are just a few from the available research studies but they prove a point.

Final Conclusion To Glycemic Index Charts

What I wanted to point out here is that even if you are thinking of using the glycemic index charts as a proper way to select your food choices, now you have the evidence that you can’t really dictate your eating habits after something that’s been based on isolation of a certain food.

What I mean by this is that if you are like me or any other person of this planet, you won’t be only eating a white bread for breakfast or 20 potatoes for dinner.

Most foods come combined and the final interaction doesn’t really matter: the GI of a separate food can be lowered or raised, depending on the combination you make but there are just too many factors and variables that need to be accounted that prove GI as an inefficient tool for food selection.

Also don’t forget about calories.

These are the main thing that can help you gain or lose weight.

If you have a story about how you tried to implement the GI in your food selection “adventure”, comment in the section bellow.

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