The Insulin Index sheds some light on the mechanics of getting an anabolic response via insulin in the absense of CHO intake. Whey protein in particular has a high insulin index which allows those of us who are fat adapted to have both the necessary insulin surge (not a MEGA-surge from a bunch of dextrose and other junk!)and allows insulin to be elevated in the presence of both GH and IGF-1, which is contrary to what a carb-burner will get. Yet again, carb-cycling proves superior in the long haul.
This ties in nicely with Doc’s assertion in the above post that you DONT need CHO to get the anabolic effect from peri-workout nutrition. And by avoiding CHO, we continue to burn fat as our primary fuel. Much like seeing that T levels drop after exercise and thus concluding that people shouldn’t weight train, people look at a “snap-shot” right after training and insist that CHO is necessary for the maximum anabolic burst post exercise. We don’t look at a snap-shot, boys. We look at the big picture. Just like T elevates in a rebound fashion to allow for anabolism in the big picture, eating peri-workout nutrition with proteins and aminos only will allow you to get better cumulative results without hampering fat loss.
As Doc points out, when you’re fat adapted, things work differently. Not all guru given “snap-shot” information is applicable. Again, if we looked short term, we’d think that weight training is detrimental to testosterone levels and thus conclude that it is contraindicated for growth.
See how looking at a “sound bite” rather than the whole converstation can lead you to seemingly intelligent conclusions that are actually wrong?
Interesting, eh?
Alert
The Insulin Index
by David Mendosa
Wednesday, May 3, 2006
Lots of people are wondering whatever happened to the insulin index. I wondered too, so I asked Susanna Holt.
Dr. Holt developed the insulin index about a decade ago when she was working on her Ph.D. at Australia?s University of Sydney. Her work was exciting but preliminary.
She tested just 38 foods and found that their glycemic index and insulin index values were highly correlated. But there was a big exception.
Their most interesting finding was that ?protein-rich foods and bakery products (rich in fat and refined carbohydrate) elicited insulin responses that were disproportionately higher than their glycemic responses.?
The American Journal of Clinical Nutrition published her findings in a 1997 article, ?An Insulin Index of Foods: The Insulin Demand Generated by 1000-kJ Portions of Common Foods?. My 2003 article about the insulin index summarized and popularized that research.
Some people think that the insulin index is even more useful than the glycemic index. It makes sense to compare these two indexes, because Dr. Holt developed the insulin index while working with Dr. Jennie Brand-Miller, who has done the most work on the glycemic index.
We still don?t know why there are differences between glycemic and insulin index values and what significance they have. ?Some foods (such as meat, fish and eggs) that contain no carbohydrate, just protein and fat (and essentially have a GI value of zero), still stimulate significant rises in blood insulin,? Dr. Brand-Miller wrote in her best-selling book, The New Glucose Revolution (New York: Marlowe and Company, 2003, pages 57-58). ?We don?t know how to interpret this type of response (low glycemia, high insulinemia) for long-term health. It may be a good outcome because the rise in insulin has contributed to the low level of glycemia. On the other hand, it may be not-so-good, because the increased demand for insulin contributes to beta-cell ?exhaustion? and the development of type 2 diabetes.?
Because I would love to see work on the insulin index continue, I recently wrote Dr. Holt. She replied that she would have loved to keep working on it, ?but the opportunity just isn?t there for me.?
However, she added an intriguing finding. In addition to milk, she says that chocolate also produces a higher than expected insulin response. This includes plain chocolate, chocolate bars and especially chocolate flavored protein bars and drinks. ?I think this is probably due to the combination of sugar and fat (and protein for the protein bars and drinks) and the high palatability of chocolate-flavoured foods,? she wrote me.
?One of the last research studies I did was comparing the effects of two different breakfast meals on blood glucose, insulin, and incretin (GLP and GIP) responses,? she wrote. ?The meal with cow?s milk in it produced large GIP and GLP-2 responses, which could be a good thing in people without any insulin resistance, as the GLP-2 is known to be involved in the satiety cascade.?
Apparently it is the whey in milk that produces a high insulin response. She directed my attention to an article by Swedish and Danish scientists that The American Journal of Clinical Nutrition recently published, ?Glycemia and insulinemia in healthy subjects after lactose-equivalent meals of milk and other food proteins".
So, should we avoid milk and chocolate or eat more of it? I would hardly recommend one or the other until we learn more about the significance of the high insulin responses that they trigger. But it?s clear than the glycemic index remains as relevant as ever for determining which carbohydrate foods trigger high blood glucose levels.
The research on the insulin index of foods is intriguing but limited. Only 16 peer-reviewed articles in MEDLINE even mention the term “insulin index,” and only one of them actually reports the results of food comparisons. By comparison, 244 peer-reviewed articles mention the glycemic index.
They?found that glycemic and insulin scores were highly correlated.
That study is “An Insulin Index of Foods: The Insulin Demand Generated by 1000-kJ Portions of Common Foods” in the American Journal of Clinical Nutrition 1997, Vol. 66: pages 1264-1276 by Susanne HA Holt, Janette C. Brand Miller, and Peter Petocz. The three co-authors were then associated with the University of Sydney in Australia. Susanne Holt was then a graduate student working under the supervision of Janette Brand Miller, and Peter Petocz provided statistical support. Subsequently, Ms. Holt?now Dr. Susanna Holt?obtained her Ph.D. degree and is directs the Glycemic Index Research Service (SUGiRS) in the University of Sydney’s department of biochemistry. Ms. Brand Miller?now Professor Jennie Brand-Miller?directs glycemic index research at the University of Sydney’s department of biochemistry.
They tested only 38 foods and found that glycemic and insulin scores were highly correlated. There most interesting finding was that “protein-rich foods and bakery products (rich in fat and refined carbohydrate) elicited insulin responses that were disproportionately higher than their glycemic responses.”
One J.S. Coleman finds the insulin index to be superior to the glycemic index. Comparing the insulin index study cited above with glycemic index studies, the Insulin Index article states that “their food choice method is more realistic, and their method more thorough than the GI method.”
What that author apparently fails to realize was that the leading researchers of the glycemic index and the insulin index are the same people. Here is what Professor Brand-Miller has to say about the insulin index in the latest version of her best-selling book, The New Glucose Revolution (New York: Marlowe and Company, 2003, pages 57-58:
While it’s clear that the insulin demand exerted by foods is important for long-term health, it doesn’t necessarily follow that we need an insulin index of foods instead of a glycemic index. When both have been tested together, the glycemic index is extremely good at predicting the food’s insulin index. In other words, a low-GI food has a low insulin index value and a high-GI food has a high insulin index value. Furthermore, the level of glucose in the blood is directly related to adverse reactions such as protein glycosylation (linkages between glucose and protein) and oxidative molecules.
There are some instances, however, where a food has a low glycemic value but a high insulin index value. This applies to dairy foods and to some highly palatable energy-dense “indulgence foods.” Some foods (such as meat, fish, and eggs) that contain no carbohydrate, just protein and fat (and essentially have a GI value of zero), still stimulate significant rises in blood insulin.
At the present time, we don’t know how to interpret this type of response (low glycemia, high insulinemia) for long-term health. It may be a good outcome because the rise in insulin has contributed to the low level of glycemia. On the other hand, it may be not-so-good, because the increased demand for insulin contributes to beta-cell “exhaustion” and the development of type 2 diabetes. Until studies are carried out to answer these types of questions, the glycemic index remains a proven tool for predicting the effects of food on health.
The following table shows how the glycemic scores and insulin index of these 38 foods compare. Note that here the glycemic scores are based on white bread set to equal 100, although the now more common glycemic index sets glucose to be to equal 100.
Especially note that glycemic scores differ in other ways from the glycemic index. “It’s important to discriminate between glycemic index values?for 50 gram-carbohydrate portions of foods?and glycemic scores?for 1000 kJ portions of foods,” the lead author of the study, Dr. Susanna Holt, writes me.
“In the insulin index study, we measured glycemic scores and insulin scores for 1000 kJ portions of foods. They are not GI values. In a healthy person that has fasted for more than 10-12 hours overnight, cheese and steak can cause a small rise in blood glucose in the second hour of our 2 hour test periods due to gluconeogenesis. Also the normal fluctuations in blood glucose around the fasting value that our experiments start from produce some area above the fasting blood glucose level , which is used to calculate both GI and glycemic score values.”
Food Glycemic # Insulin Score
CEREALS
All-Bran 40 32
Porridge (Oatmeal) 60 40
Muesli 60 40
Special K 70 66
Honeysmacks. 60 67
Sustain 66 71
Cornflakes 76 75
CARBOHYDRATE-RICH FOODS
White pasta 46 40
Brown pasta 68 40
Grain [rye] bread 60 56
Brown rice 104 62
French fries 71 74
White rice 110 79
Whole-meal bread 97 96
White bread 100 100
Potatoes 141 121
PROTEIN-RICH FOODS
Eggs 42 31
Cheese 55 45
Beef 21 51
Lentils 62 58
Fish 28 59
Baked beans 114 120
FRUIT
Apples 50 59
Oranges 39 60
Bananas 79 81
Grapes 74 82
SNACKS AND CONFECTIONARY
Peanuts 12 20
Popcorn 62 54
Potato chips 52 61
Ice cream 70 89
Yogurt 62 115
Mars bar 79 112
Jellybeans 118 160
BAKERY PRODUCTS
Doughnuts 63 74
Croissants 74 79
Cake 56 82
Crackers 118 87
Cookies 74 92
