T Nation

GI and Insulin Index

I just finished reading the Berardi articles here on T-mag and one thing really caught my attention. He mentioned research where a very high GI cereal turned out to have a lesser insulin index than all bran cereal. Now, in practice, what does this signify? Should I be ditching the all bran cereal and heading for the special K??


He also said that research on the insulin index is lacking so it is probably better to stick with what works better for you or keep relying on the GI scale.

It means most people don’t understand how the GI was developed and what that means towards their use of it. IOW, potatoes, carrots and corn (among many other things) are not as bad when it comes to insulin responses as one would think based on the GI.

The GI is just another example of someone thinking they have found the “silver bullet” without fully understanding or taking into account all of the surrounding factors.

But in the meantime, what is the recommendation?


“Following the GI isn’t really a good idea, you should follow the Insulin Index. Problem is: we don’t have enough data yet, so you’re screwed”

seems to be the message.


Here’s what I would do. Not perfect, but a nice quick thing you can do:

(1) Determine the GI score of your carb source (eg carrots ~GI score between 92 and 101 depending on which table you look at …bad right? NO - follow along).

(2) Determine how many or what portion it would take of the carb source to get 50g of carbohydrates (eg for carrots it would take, depending on size, 7 to 10 carrots to get ~50g of carbohydrates). Chances are, if you know these limitations, the Glycemic Load, Insulin Index, Glycemic Quotient or whatever else they come up with will not tell you much more than what you can figure out with the GI and reason.

(3) Ask yourself: “How much of this carb source do I plan on eating?” If it is somewhere around a portion that would equal 50g or more of carbs, don’t eat it. If you plan on eating less or much less than a portion that would provide 50g of carbs, eat up! (eg unless your name is Bugs, chances are you will not eat 7-10 carrots in a week, let alone one sitting…so, go ahead and munch that carrot).

Of course, you could just be lazy, follow the GI charts, get bored eating and live without such great foods as carrots, corn,potatos and pumpkins. The GI is a tool and is useful, you just have to understand how it was developed and the inherent limitations in it.

That look’s like sound advice, and I think that’s what I’ll do. Thanks!