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the doc
01-12-2002, 09:44 AM
Enjoy!

J S Coleman
Bionomic Nutrition Forum, 2000
This article has been written to clear up some of the dietary inaccuracies and myths surrounding the role of different types of food, and how they affect insulin secretion. Some dietary authorities and fad diet groups are now proposing dietary changes based on the glycemic (i.e. glucose in blood) index (GI) method. At the moment the GI method has yet to be shown to be anything other than a crude yardstick, and so it had not gained broad scientific acceptance. The GI method was developed to rank foods according to the extent to which they increase blood glucose concentrations, this being a useful guide to help those people with diabetes choose foods with lower glycemic responses. Insulin promotes the uptake of glucose from general circulation, into the cells for use in energy production.

Some of the over-simplistic concepts being circulated run along these lines:

foods high in carbohydrate have higher glycemic indexes than protein rich foods...
and therefore high protein foods (meat/fish) are safer
fruits are high in sugar...
and therefore have higher glycemic indexes
a higher glycemic index means the body must produce more insulin...
and therefore low glycemic index foods are safer
A better attempt at understanding how diet affects insulin levels has been proposed by Susanne HA Holt, Janette C Brand Miller and Peter Petocz in their paper entitled "An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods" (Am. J. Clin. Nutr., Nov 1997, Vol.66, Iss.5, p.1264-76). The authors point out that their results are "preliminary", and it must also be noted that only a few foods (38) have been studied. Even so, their food choice method is more realistic, and their method more thorough than the GI method. Their conclusions challenge some previous beliefs based on GI findings.

In this paper, the researchers identify a number of problems with the GI method. The most obvious problems are that GI uses a 50g carbohydrate serving of foods, which is not representative of how people really eat, and also that although protein rich foods produce a low blood glucose response, it does not follow that there is a correspondingly low insulin response. In short, the GI method is inaccurate, incomplete and unrealistic, although perhaps better than nothing. The researchers state that the GI concept does not consider concurrent insulin responses, and that little research reports both a GI value and accompanying insulin responses. Real diets do not consist of meals where single food items are eaten to 50g carbohydrate levels, in addition when foods with different qualities are mixed; the insulin response can be unpredictable. The GI method is not an accurate predictor of insulin response, and the new paper proposes a method for obtaining a more realistic assessment of dietary factors to insulin response, based on a more realistic isoenergetic basis.

There are a number of factors other than carbohydrate content that mediate in stimulation of insulin secretion, for example it is stated that protein-rich foods or the addition of protein to a carbohydrate-rich meal can stimulate a modest rise in insulin secretion, without increasing blood glucose concentration. Similarly adding fat to a carbohydrate-rich meal also increases insulin secretion even though plasma glucose response is reduced. Several insulinotropic factors have been found to potentiate the stimulatory effect of glucose and mediate posprandial insulin secretion. These factors include fructose, some amino acids and fatty acids, and gastrointestinal hormones. So protein and fat rich foods also induce substantial insulin secretion despite producing relatively small blood glucose responses.

The GI is a ratio of the measure of blood glucose levels found after eating a 50g portion of white bread (or sugar), to a 50g carbohydrate portion of the test food. White bread is often taken as the reference food, and given a score of 100%, so a food that produces half of the blood glucose response over the same test period would be given a score of 50%. In contrast, the Insulin Score is a ratio based on insulin levels found over 2 hours after consuming a 1000kJ meal of the test food, to a 1000kJ meal of white bread. The equation is similar to that developed for the GI value. The glycemic score measures blood glucose levels in a similar fashion.


Although personal variations in response to identical meals occurred in the study, the researches found a stable correspondence between foods and insulin and glucose scores across the group. On average the snack foods produced the highest food group IS, followed by bakery products, carbohydrate-rich foods, fruit, protein rich foods and then breakfast cereals respectively (see figure). The researchers found significant variations in foods of the same food group, so food group alone is not a good predictor of insulin or glucose scores. Furthermore, at the food group level, variations are not as dramatic as between specific foods, so that generalisation about food groups and insulin or glucose scores are inaccurate. The graph to the right adapted from the study results, shows the mean glucose and insulin scores of the food groups.

The researchers did find that jellybeans (made of sugar and animal protein) produced the highest mean IS, whereas peanuts (an oily legume) had the lowest IS. The reference food, white bread, consistently had the highest glucose and insulin responses, and had a higher insulin score than most of the other foods. On average fish produced twice as much insulin secretion as did the equivalent portion of eggs. Amongst the few fruits examined, oranges and apples produced significantly lower scores than grapes and bananas, despite similar carbohydrate content. Potatoes had significantly higher scores than all of the other carbohydrate-rich foods. White and brown rice have similar scores, as do white and brown pasta. Despite containing similar amounts of carbohydrate, jellybeans induced double the insulin secretion as any of the four fruits. These findings are presented in the figure below, showing both scores for all 38 foods, in their food groups.



From the above data, we can conclude at least, that some fruits do not produce insulin responses much greater than protein rich foods such as beef or fish. Perhaps surprisingly, the insulin scores for cheese, beef and fish are greater than those for starchy foods such as porridge. This will lay rest to the claim that protein rich foods are somehow insulin safe when compared to carbohydrate rich foods. Each food must be evaluated individually, and more realistically, each meal.

Overall, although GS is a good predictor of IS, the researchers found that the nutrient levels analysed, only explain 33% of the variation of the insulin response for the foods studied. It seems then, that the individual properties of a food, other than those studied here, account for two-thirds of the remaining insulin response.

In the authors discussion they conclude that important Western staples, bread and potato were among the most insulinogenic foods. Highly refined bakery and confection also induce substantially more insulin secretion per kilojoule or per gram of food than did other test foods. If any of these high carbohydrate foods were eaten with either fat or protein rich foods, say bread and cheese or meat, or pizza, then the scores would be far higher. The authors also note, as above, that some protein-rich foods induce as much insulin secretion as some carbohydrate-rich foods. Fibre was not found to predict the magnitude of insulin response. Their conclusion is that the findings imply that typical Western diets are likely to be significantly more insulinogenic than traditional whole food diets. The research method is not ideal, because some of the serving sizes, for apples, oranges, fish and potatoes were felt to be unrealistic, presumably due to excess. However, the method is still superior to the crude 50g carbohydrate portions found in GI study meals. The researchers have found that increased insulin secretion did not account for the low glycemic responses produced by low-GI foods such as pasta and porridge. These findings challenge the scientific basis of carbohydrate exchange tables, which are now clearly making invalid assumptions.

Other important factors such as the rate of gastric emptying, rate of starch digestion, the amount of rapidly available glucose and resistant starch, the degree of osmolarity and the viscosity of the gut's content, must be significant factors in influencing the degree of postprandial insulin secretion. As a cautionary note, the researchers suggest that additional studies are needed to determine whether the IS concept is useful, and reproducible, and more importantly whether it is predictable in a mixed-meal context. When these questions are answered the role of IS in the treatment of diabetes, hyperlipidemia and overweight will be better known. Until then, we can at least dispatch with the some of the urban diet myths that were presented at the top of this article. We can conclude that protein-rich foods are not necessarily some insulinogenic panacea, and that fruits are not some kind of sweet bogeyman. We also find that food refining and mixing is potentially problematic.

Another related set of pop myths, being circulated again by similar nutri-babble factions, concern the claim that fruits contain so much sugar that they are "addictive", and also that sugar is itself addictive. While it is true that the taste of sugars on the tongue does promote release of satiety chemicals in the brain within seconds (an adaptive feeding reflex common in mammals - perhaps more so in frugivorous primates?), a thorough examination of all Medline papers revealed no relevant papers concerning fruit or sugar consumption and addiction. Intriguingly, although the reporters of these anecdotes identify "cravings" for fruit as suggestive of "addictive" properties, reported cravings for animal foods are somehow seen as adaptive survival reflexes. Should we be concerned about fruit addiction stories? In another light scan of the entire Medline record at Healthgate, I found over 3,500 articles concerning the healthful effects of fruit consumption, but only a handful concerning a few special problems induced by fruit eating in some cases, such as workers at citrus farms suffering tooth erosion. Obviously if fruit really is addictive, then we would expect to find fruit sales soaring above those of cheese and beef, with cattle farmers queuing to buy fruit trees and proffer from the new market in addiction - but the cold facts of the matter say otherwise.

While not wishing to add to the surfeit of dietary anecdotes by peddling more patent absurdities, observations of cycles of bingeing and withdrawal while adding more sweet fruits to the diet have been found. Eventually though, over a period of 1 to 2 years, in all cases I have seen, these "cravings" remedy themselves, and one adopts a more varied diet. Perhaps these "cravings" are in fact some part of a healing and then balancing process, as the body realigns feeding behaviour to maintain homeostasis. As they often say, "more research is needed".


http://www.zonehome.com/images/igfgroup.gif
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http://www.zonehome.com/images/isgs.gif

The_Chicken_Daddy
01-12-2002, 10:45 AM
nice one doc, but why didn';t you just post the link? :)

Wizard
01-13-2002, 03:27 AM
That's cool :cool:

Bump

Wizard
01-13-2002, 03:41 AM
In addition I will post the satiety index to complete the puzzle (sp?) :

Bakery Products
Croissant
47%
Cake
65%
Doughnuts
68%
Cookies
120%
Crackers
127%

Snacks and Confectionary
Mars candy bar
70%
Peanuts
84%
Yoghurt
88%
Crisps
91%
Ice cream
96%
Jellybeans
118%
Popcorn
154%

Breakfast Cereals
Muesli
100%
Sustain
112%
Special K
116%
Cornflakes
118%
Honeysmacks
132%
All Bran
151%
Porridge/Oatmeal
209%

Carbohydrate Rich Foods
White bread
100%
French fries
116%
White pasta
119%
Brown Rice
132%
White rice
138%
Grain bread
154%
Wholemeal bread
157%
Brown pasta
188%
Potatoes
323%

Protein Rich Foods
Lentils
133%
Cheese
146%
Eggs
150%
Baked beans
168%
Beef
176%
Fish
225%

Fruits
Bananas
118%
Grapes
162%
Apples
197%
Oranges
202%

If you want to lose weight, avoid the lower numbers!

the doc
01-13-2002, 05:08 PM
wow there was some really cool info in that article.

to sum it up proteins are far more insulin stimulating than the GI scaloe would indicate
So are sweets and baked goods.

ALthough not mentioned, i'm sure whey is quite insulin stimulating as well.

Wizard
01-14-2002, 02:51 AM
:dj:

Yup,whey raises 'slin because it has a different balance of aminos.(more L-arginine,which raises insulin)

Avatar
01-14-2002, 10:25 AM
good article doc. Would you mind posting a link to it? thanks.

notSoBig Guy
01-14-2002, 11:40 PM
I inject my own insulin, for obvious reasons. Does this apply to me?

the doc
01-15-2002, 06:27 AM
uhhh... no. This study measured endogenous insulin after 2 hrs of eating 1000kJ (~225 kcal) of food. I have no idea how a diabetic rpofile should be. SInce you can't test blood amino levels i dont see how you could inject in response.

Wizard
01-15-2002, 12:19 PM
Consult your doctor. You're type II?

notSoBig Guy
01-15-2002, 12:24 PM
Type 1, oral insulin wouldn't work on me. I find when I inject more insulin, I gain weight a lot easier, but the cost of the insulin makes me relectunt to raise my insulin dosage. Of course I consult my doctor when I wanna increase dosage.

Avatar
01-15-2002, 04:42 PM
good article doc. Would you mind posting a link to it? thanks.

the doc
01-15-2002, 08:46 PM
Originally posted by Avatar
good article doc. Would you mind posting a link to it? thanks.

though i was seeing double ...lol


sorry avatar, here it is

http://www.zonehome.com/zlib0025.htm

the doc
01-15-2002, 08:46 PM
oh yea chicken i was experimenting on how to open pages in threads

the doc
01-15-2002, 08:47 PM
:dj:

Avatar
01-16-2002, 08:53 AM
Originally posted by the doc


though i was seeing double ...lol


sorry avatar, here it is

http://www.zonehome.com/zlib0025.htm

lol you were :)
I just wanted to save the link on my browser.

cheer mate. :thumbup:

aeckhardt
01-16-2002, 09:21 AM
I've read this before, but I never really thought about it until now.

Can I conclude from this article, that for a cutting diet it might possibly be better to not be going low carbs- but to instead be eating moderate carbs such as All-bran, fruits, oatmeal, etc. Derive any fat from nuts. And try to get protein from eggs, and chicken.

I wonder what chickens IS is. The IS scores seem to increase whenever fat or protein are involved. It seems chicken might be low because it is mostly just protein, so there is no fat to increase the IS.

Wizard
01-16-2002, 11:01 AM
I don't wonder what chicken IS is because chickens suck anyways.. (estrogen)

Don't go mad on the GI index.I think that it's not a big deal.

Always prefer comsuming complex carbs like oatmeal,sweet potatoes AND potatoes,rice,pasta BUT avoid all sugars.
Potatoes,rice and pasta may be high in the GI index but if you eat some veggies or have 5-10grams of fiber (like psyllium husk) with your meal,you lower very much the GI of the meal.

It's a better way to lower it than using fat to produce the same effect.(fat is better combined with protein).

Marcel
01-16-2002, 11:07 AM
Wizard - si eres una estrella. haha:cool:

Doc - tu tambien eres una estrella.:cool:

Wizard
01-16-2002, 11:12 AM
Marcel:Nadie duda que soy la estrella aqui ;)

the doc
01-16-2002, 11:24 AM
i am also a what ? lol

Wizard
01-16-2002, 11:32 AM
*lol*

Tryska
01-16-2002, 11:35 AM
*starts something*


i think he called you a w a n k e r, doc.

gino
01-16-2002, 12:26 PM
So would it be safe to say that the foods in the lower end of the GS/IS chart with the largest difference between GS and IS scores would be the best to eat while on a cutting diet? I mean, as far as insulin and glucose equating to fat stores, what's one without sufficient amounts of the other going to do? If you have a food like fish or beef with an average IS but much lower GS, wouldn't that equate to much less potential for fat storage?

gino
01-16-2002, 02:22 PM
Damnit, answer me before I get fat.

lol

The_Chicken_Daddy
01-16-2002, 02:25 PM
Gino, you've been ripped to fcuk before so you obviously know what works for you. Why bother changes methods now when you know the current one works?

gino
01-16-2002, 02:35 PM
Yeah I know. Just analyzing it a step further so I can maybe get ripped easier.

The biggest surprises to me were beans, brown rice, and white pasta.

aeckhardt
01-17-2002, 10:20 AM
Actually Gino I would see it the other way. I would want a low Insulin response and a high GI repsonse. That way the low level of Insulin would shuttle the high amount of nutrients to muscles, but never really turn anything to fat.

What's your fav. way of getting ripped- since Doc I think it was, said you've done it before?

gino
01-17-2002, 11:18 AM
Originally posted by aeckhardt
Actually Gino I would see it the other way. I would want a low Insulin response and a high GI repsonse. That way the low level of Insulin would shuttle the high amount of nutrients to muscles, but never really turn anything to fat.

What's your fav. way of getting ripped- since Doc I think it was, said you've done it before?

I wasn't really specifying one way or the other. I was referring ONLY to fat storage and not nutrients going to muscles. As far as shuttling nutrients to cell, yes, high insulin response is good. However, as far as fat is concerned, whats one without enough of the other?

High glucose and low insulin = ?
High insulin and low glucose = ?

My guess is that high amounts of one without much the other won't result in fat gains, but I'm hoping someone could put a more scientific explanation because I'm really lazy. lol

As far as losing bodyfat goes, I have had more success with manipulating my diet than increasing cardio as far as fat loss AND retaining muscle goes. I increase cardio slightly, but it's only low intensity cardio a few times a week.

Avatar
01-17-2002, 11:57 AM
I have a question - if beef and fish produce as much if not more insulin than porridge and some fruit, how come you can get into ketosis or maintain it with beef and fish, yet are thrown out of ketosis if any substantial amount of porridge or fruit is eaten (+20-30g worth)?

Wizard
01-17-2002, 12:07 PM
1.To enter the state of ketosis you must eat very high amounts of fat which lowers insulin.

2.Fruit refills very fast the liver glycogen stores.

3.When you are in ketosis you don't want glucose running in your blood but ketones.
So,as far as ketosis is concerned,you better look at the Glucose scores.Insulin will be lowered (by the fat consumption) anyways...

Keep in mind that carbs are converted to glucose at a rate of 100% whereas protein is converted to glucose at a rate of 58% and fat at 90%.

the doc
01-17-2002, 01:32 PM
but fat cannot be converted to glucose (at least in humans) this is because the oxidation of pyruvate is essentially irreversible

Wizard
01-17-2002, 01:45 PM
haha fcuk.. I meant that fat is converted to ketones at a rate of 90%. :D

breeze
01-17-2002, 01:53 PM
Originally posted by Wizard
1.To enter the state of ketosis you must eat very high amounts of fat which lowers insulin.

2.Fruit refills very fast the liver glycogen stores.

3.When you are in ketosis you don't want glucose running in your blood but ketones.
So,as far as ketosis is concerned,you better look at the Glucose scores.Insulin will be lowered (by the fat consumption) anyways...

Keep in mind that carbs are converted to glucose at a rate of 100% whereas protein is converted to glucose at a rate of 58% and fat at 90%.

You are contradicting yourself. If fat converts to glucose at a rate of 90% then there will be an insulin response. It all depends on how much fat you eat at one sitting. Since no one eats fat by it self, I want to see any of you drink a liter of oil or lard, eating fat with carbs or protein raises the insulin response higher than if you ate the carbs alone or protein alone.

Wizard
01-17-2002, 02:03 PM
Originally posted by Wizard
haha fcuk.. I meant that fat is converted to ketones at a rate of 90%. :D

HELLO!!!

Prelude
01-18-2002, 07:39 AM
OK I got really confuse with this. Somebody please explain this in simpler terms. Is this IS saying that beef and fish will spike insulin just like a starchy carb or what?:help:

breeze
01-18-2002, 08:26 AM
Originally posted by Prelude
OK I got really confuse with this. Somebody please explain this in simpler terms. Is this IS saying that beef and fish will spike insulin just like a starchy carb or what?:help:


Anything you eat will more or less cause an insulin response. Some more than others. Beef and fish will cause less of an insulin rush than most carbs.

the doc
01-18-2002, 09:11 AM
what this is saying is that protein's insulin effect is not at all measured by GI. Thus consuming high amounts of protein for fat loss purposes is not a good idea.

also, Gi measures blood sugar, but as you can see for some high gi foods there is relatively little insulin needed for lowering sugar levels.

Prelude
01-18-2002, 10:05 AM
So on cutting, excess beef = insulin response + fat from beef = fat storage. I see that eggs are not that bad, would that be the same case for chicken or lean cuts of beef or fish. I was surprised that bananas,apples, and grapes did well. But these fruits should still be avoided when cutting, right? I wonder if there is a more complete list for all foods.

The_Chicken_Daddy
01-18-2002, 10:50 AM
but the fat from the beef will 'null' the insulin secretion somewhat.

Fruits avoided during cutting? not necessarily, but definatley moderated in favour of more complex forms of carbohydrate.

If you followed these guidelines to the letter then you're restricting yourself to very little choice and variety and most likely will be restricting the 'best' muscle building foods.

body
01-27-2002, 05:46 AM
bump.
its a good one.