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I was reading article about the GI, and something is bothering me.Basicly the idea of using High GI on CBL is that it causes big spike of insulin and then it has a big fall down.However according to definition, GI is by no means telling us how fast our insulin level drops.GI is AVERAGE from the glucose levels in 2-3 hours after intake of carbs, or Integral of the chart devided by time of mesurement, if you will.For example this gif:http://raisingchildren.net.au/verve/_resources/GI-graph.gifIs WRONG, actually according to definition, both these products will have similar GI (in 2 hour period), because the average is what counts, not the peek.So my point is - there is actually no known indicator that shows us how fast our body will be done taking care of what we ate. Or maybe someone can proove me wrong? Not really sure how to look at this one. I'd LOVE to hear about that from Kiefer himself, or Naomi! 🙂Cheers!
You're right, GI doesn't say anything about how fast you will be done. It only indicates how fast the carbohydrates are available as blood glucose in your body. Faster means more insulin in a shorter period, which again clears the blood glucose faster. And no, those two foods do not have the same GI. The area under the curve is significantly different.The average you're thinking about is probably the average of the 10 people tested for that specific food. 🙂
You're right, GI doesn't say anything about how fast you will be done. It only indicates how fast the carbohydrates are available as blood glucose in your body. Faster means more insulin in a shorter period, which again clears the blood glucose faster. And no, those two foods do not have the same GI. The area under the curve is significantly different.The average you're thinking about is probably the average of the 10 people tested for that specific food. 🙂
I found definition, that GI is area under curves, so was that wrong?And no, I was not talking about the average from amount of people, heheh:D
The gif is correct according to the definition you found. The area under the curve is greater for the red curve with the high peak.Even if the definition of GI doesn't mention anything about how steep the curves are, a peak will produse a much greater area than a flat curve. They are measured over a set period of time, so height(blood glucose levels) will dictate the area under the curve.
Also, notice that blood glucose levels are back at the starting point in half the time for the high GI food in the picture.
The area under the curve is greater for the red curve with the high peak.Well we don't have values, but it has some values beneath 0, so areas can equalize, summing up to almost the same GI.
a peak will produse a much greater area than a flat curve
From math poin of view this is not true 🙂 There can be peek superior to flat and than sprint down below the flat curve, and summary will show that they have equal AUC
Also, notice that blood glucose levels are back at the starting point in half the time for the high GI food in the picture.
That is true, but problem is GI is not indicating that - just the chart I just pasted here.
From http://www.glycemicindex.com/about.php (They use the same chart you found.) :"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."In the context of CBL and CNS, this is what we want. A sharp rise in blood glucose creates a spike in insulin.From a math point of view, my statement was true. You need to read the next sentence as well: "They are measured over a set period of time, so height(blood glucose levels) will dictate the area under the curve.". Both curves in the example feature roughly the same x-value, and even if they didn't, dipping below the starting value would not produce a negative area.
Watch out for my mad paint skills! haha:DLook at the chart that I made.According to definition area under chart is what interests us right? BOTH of the curves are summed in the 2 hour period (it doesn't matter that the sharp one equals 0 half the time).Higher GI will be that one that is more flat, because area is greater, however in CBL we are interested in the Peek-ish one.The definition you pasted does not cover with definition from e.g. wikipedia and any other formula for GI that I found, because of the reason that stated higher in this post.btw. I appreciate the discussion, thanks.
There's just one problem – your body does not work like that. A sharp rise in blood glucose, like your rounded curve has, does produce a sharp fall, not a slow deceleration.
There's just one problem - your body does not work like that. A sharp rise in blood glucose, like your rounded curve has, does produce a sharp fall, not a slow deceleration.
THAT is what I was missing, thank you!
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