T Nation

What's Berardi talking about?

Unless I’m mistaking, Berardi writes in this issue that the descrepency between glycemic effects of All-Bran (low GI) and Corn Flakes (high GI) turn us to the insulin index. But in the article on the insulin index by JS Coleman, All-Bran is one of the lowest foods compared, only eggs and peanuts are lower. He also says that the protein in conjunction with the carbs in All-Bran may be eliciting the big insulin response. We’ve been told that eating carbs ALONE is a biggest mistake in regards to regulating blood sugar (because there is no postprandial glucagon reaction?). What’s going on? And are either the GI or the II really useful for either bulking or dieting? It seems that whatever you’re going to eat, you’re going to get an insulin response that will stop fat burning. Maybe the key is the RATE of insulin secretion(free-form BCAAs make more of a spike than solid protein)… Whatever, we need clear answers on this because I don’t know what to eat.

Drink more beer!

He also said that the blood glucose levels cleared faster with the all bran than the cornflakes. This would make it a better food choice because prolonged insulin spikes hurt fat loss. Another thing he said is to keep eating what makes you lean and that more research needs to be done on these topics.

If that’s regular All Bran, it’s not only bran, it has some added maltodextrin or sugar. Regular All Bran is about .2 sugar by weight. If I remember correctly, added sugar usually affects the II of the food more than the GI and fiber the opposite. I’m not sure about that one, but I remember reading it. The fiber would cause a low GI and the sugar would cause a greater insulin response with the protein. Also, to get 15g protein the participants would need about 2 cups of All Bran. That’s just nasty.

A quote from the Berardi’s aricle.

"While this study adds a whole lot of confusion with respect to selecting appropriate carbohydrate choices (since it now looks like all bran might be worse than even corn flakes in terms of the insulin response), I believe that it does indicate that the insulin index might turn out to be a better determinant of carbohydrate quality than the glycemic index. "

Berardi actually writes: “Therefore the reason the high GI corn flakes group had a larger rise in blood glucose is because they got a smaller insulin response and a slower clearance of the blood than the low-GI group.” But
Corn Flakes is much higher on the II than All-Bran, so how can All-Bran elicit more of an insulin response? JasonL, you bring up the issue of SPEED of insulin secretion, something which I’m interested in. 6 grams of free-form EAA produces a tremendous insulin response, much more than any carbohydrate. But perhaps the insulin spike of carbohydrates lasts longer… In any event, Berardi’s article actually includes this wondrous conclusion, which implies that we that the II and GI are INVERSELY related:
“the low blood glucose response is probably due to the large insulin response and the subsequent rapid uptake into the tissues (Rd).”

Alright, in the absence of any glitches, this should post this time.

I just wanted to first off make it clear that this is not JB’s research or his interpretation of the research conducted or the methods involved.

That said, here’s a little more colorful explanation of what’s going on here with this research.

Currently we have a very comprehensive list of the Glycemic Index of various foodstuffs (i.e. carbs). In addition, we have a very minute Insulin Index of various foodstuffs (i.e. protein, carbs, etc.). Because of the limited II, we have based the majority of our carbohydrate choices on the glycemic index.

However, it now appears that the glycemic index is not an accurate and precise tool for measuring the physiological response to foods, in some cases at least.

Basically, we have been told that the glycemic index is representative of the rate of appearance (Ra) of glucose into the blood stream. That is, a lower GI foodstuff will have a lower Ra, relatively, than a higher GI foodstuff.

However, this is only part of the story. The measured glucose in the bloodstream at any time is not only a function of the Ra of glucose, but also the rate of disappearance (Rd) of glucose, which is thought to be governed by insulin (which drives home the glucose…kinda like Happy Gilmore sends the ball home).

Anyway, think of this like a sink (i.e. the bloodstream). The faucet is the Ra, while the drain is the Rd. If the drain is opened large enough such that the Rd of glucose exceeds the Ra of glucose (which appears to be the case in the All-bran situation), then the Ra will actually appear relatively low.

I hope this clears up some things…or prompts more questions. Either way, it’s a good discussion and begs the creation of a comprehensive insulin index of various foods.


What they are saying is

With the research JMB refered to, cornflakes show a low insulin response, where as the all bran showed a high response.
But in the available II reference, all bran has a low insulin index, while cornflakes has a high.