GI lists and branded foods

[HelenM]

I didn't want to mention this in the other thread where it came up but I think its worth pointing out that the GI of some manufactured foods varies from country to country. They use different recipes .
A good example of this is in fact special k. Special K tested in Australia has a gi of 54, special K in the US was 69 and that tested in France was 84!, who knows what the UK version is ( I compared the ingredients labels for France and Australia and sugar was higher in the list for France so it presumably contains more).
Actually it's a real drawback as very few British (or those from France where I live) products have been tested some of these lists on the internet are not very accurate.
Its Ok for those of us that have access to strips to check the effects on ourselves but those who are trying to follow a GI diet and have to rely on published information may be eating things that have a far higher gi than they think.
The most comprehensive list is the database on the glycemicindex website.

 

[everydayupsanddowns]

I think I know the thread you mean 🙂 I found UK and US Special K figures that differed by about 10 or 15 points.

I think part of the problem is the method by which GI is measured. I seem to remember reading one site where the test was 50g given to 100 people.

Is that all?!?

There's got to be 100 people on this forum who have a hugely different response to 50g of any food you can mention...

"What do you mean you eat bananas?!"... "Mashed potato is fine for me"... "I may as well eat golden syrup as mash"... etc etc...

Not to mention the rogues in the gallery which show that high fibre does not necessarily mean lower GI and it's a complete minefield!

 

[HelenM]

Actually it's far fewer than 100. Here is how a recognised lab does it
http://www.gitesting.com/index.php?page=meth
However there is a good correlation between different trials of the same foods.
There are actually two sets of data, one comprising all the official trials with 'normal subjects' the other all the trials done with people who have diabetes. Second table includes foods tested on people with diabetes, mostly with type 2 but some type 1. (includes the number of subjects)
http://care.diabetesjournals.org/content/31/12/2281/suppl/DC1

I do agree that it can be a minefield, particularly if you eat lots of manufactured products, less so with fresh produce but you really need to know what type of things are likely to be lower GI and realise that portion size and the density of carbs are important, something with a low gi may still be very dense in carbs so a ' portion of melon (high gi), so you are told to avoid it on some lists might do far less damage than a portion of chickpeas, fairly low gi.

 

[everydayupsanddowns]

What? Something about diabetes being a bit inconsistent and a nightmare to get your head around...? Surely not...