# GI whoa???



## caffeine_demon (Jan 7, 2011)

Looking at a few sites with GI values, there seems to be quite a large difference between the values in some cases.

eg - http://www.the-gi-diet.org/lowgifoods/
lists baked potatoes as 60

but http://www.carbs-information.com/glycemic-index-food-chart.htm
lists it as 93

why such a big difference?


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## Liz! (Jan 7, 2011)

With potato, it makes a big difference what form they are in. 

They are very quickly absorbed, on one GI scale they are the quickest thing to be absorbed, even quicker than sucrose, as they have a very simple chemical formula and brak down into sugar very quickly. A potato on your plate is similar to having a spoonful of sugar in fact.

Eaten with fat, that slows down their entry into your bloodstream. 

Mashed speeds it up. 

I eat very little potato! Wholemeal rice, wholemal pasta is a much better choise.


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## HelenM (Jan 7, 2011)

The first link gives the Univ of Sydney as a source, the second links to another website that doesn't give a source.

In fact if you look at the Univ of Sydney database you will find GIs for baked potatoes varying from 60-90+. It depends on variety and cooking time and whether or not the skin is included.
http://www.glycemicindex.com/
In general waxy potatoes cooked less long will have lower gis, floury ones cooked for a long time and eaten without skin will be higher.
All baked potatoes are relatively high but putting some fat on it will lower the GI


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## StephenM (Jan 7, 2011)

Whilst, I think, I understand GI it surely is more complex than the basic figure. Surely you also have to take the quanity eaten into acount? For instance if you eat a 100g of something that contains 10g CHO and has a high GI this may be better than 100g of something else that contains 30g of CHO and has a medium GI? Maybe a computer model is required?


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## Liz! (Jan 7, 2011)

There is a chart of the GI levels which takes that into account - for instance the GI of watermelon is really high, but as you can in no way eat enough to make it a problem, this chart takes that into account. i have it somewhere, I'll try and find it!


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## Liz! (Jan 7, 2011)

ok, found the info...

"someone more recently has taken the trouble to measure the glycaemic LOAD of foods. The glycaemic load of a food also takes into account how much of that food you have to eat to cause a significant rise in blood glucose. For instance, Watermelon has a high glycaemic index. however, watermelon contains a lot of water. You have to eat such a large amount of it to cause a significant rise in blood sugar, it has a low glyceaemic load.

if you choose foods which have a low glycaemic load for all of or for the main part of each meal, your blood sugar has a much better chance of remaining stable throughout the day."

You need to look on the internet for a chart which shows the glycaemic load not index of a food.


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## Northerner (Jan 7, 2011)

StephenM said:


> Whilst, I think, I understand GI it surely is more complex than the basic figure. Surely you also have to take the quanity eaten into acount? For instance if you eat a 100g of something that contains 10g CHO and has a high GI this may be better than 100g of something else that contains 30g of CHO and has a medium GI? Maybe a computer model is required?



This is what the GL (Glycaemic Load) diet takes into account, and it is just as you say - something with a high GI may be eaten in very small quantities in reality so won't necessarily have a huge impact on BG levels. In fact, some of the foods would need to be eaten in ludicrously huge amounts as GI uses a consistent measure of (I believe, without checking) the amount of food, eaten in isolation, which contains 100g carbohydrate. Better to follow GL rather than GI.


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## HelenM (Jan 7, 2011)

You don't need a separate chart to calculate glycemic load.  The Sydney data base also contains the GL for each  item. You can also calculate it.
GL = (GI x the amount of carbohydrate) divided by 100
so if an apple has a GI of 40 and there are 15 carbs in the apple
40x15/100=6 (a low GL)

but I don't think its necessary to use any specific numbers nor to do the calculations to work out the glycemic load.  The GI website puts it better than I can.


> Although the GL concept has been useful in scientific research, it’s the GI that’s proven most helpful to people with diabetes. That’s because a diet with a low GL, unfortunately, can be a ‘mixed bag’, full of healthy low GI carbs in some cases, but low in carbs and full of the wrong sorts of fats such as meat and butter in others. If you choose healthy low GI foods—at least one at each meal—chances are you’ve eating a diet that not only keeps blood glucose ‘on an even keel’, but contains balanced amounts of carbohydrates, fats and proteins.
> We suggest that you think of the GI as a tool allowing you to choose one food over another in the same food group—the best bread to choose, the best cereal etc.—and don’t get bogged down with figures. A low GI diet is about eating a wide variety of healthy foods that fuel our bodies best—on the whole these are the less processed and wholesome foods that will provide you with carbs in a slow release form. So what’s the take-home message?
> 
> Choose slow carbs, not low carbs
> ...


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## Liz! (Jan 7, 2011)

The number of reasons i have to disagree with that is quite large, but I think differently to a lot of people. I don't for instance think butter is an unhealthy fat. I think low fat spreads are extrmemly unhealthy. All (my definition of healthy) things, but in moderation is my motto!


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## Northerner (Jan 7, 2011)

Liz! said:


> The number of reasons i have to disagree with that is quite large, but I think differently to a lot of people. I don't for instance think butter is an unhealthy fat. I think low fat spreads are extrmemly unhealthy. All (my definition of healthy) things, but in moderation is my motto!



In today's news:

http://www.express.co.uk/posts/view...ay-not-be-bad-for-us-after-all-say-scientists


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## Liz! (Jan 7, 2011)

Aha! At last! I do a lot of reading about these things and you can know about something for YEARS sometimes before it gets reported...


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## HelenM (Jan 7, 2011)

> I don't for instance think butter is an unhealthy fat. I think low fat spreads are extrmemly unhealthy.


It's interesting what we focus in on, in the quotation this is my main 'take-away' message


> A low GI diet is about eating a wide variety of healthy foods that fuel our bodies best?on the whole these are the less processed and wholesome foods that will provide you with carbs in a slow release form.



As far as I'm concerned butter is far less processed than spreads and if I need to use a spread then I've always used butter, fortunately I can buy very good local, lowish Gi breads that don't need any spread,  so the amount I eat is definitely moderate.


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## Liz! (Jan 7, 2011)

Mea culpa Helen!


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## HelenM (Jan 8, 2011)

Liz! said:


> Mea culpa Helen!



'de rien'


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