Saturday, December 15, 2007

My Problems with the GI Index

I really have a problem with the whole GI Index concept. It is okay for those really not up on nutritional science to use as a simple guideline. Personally, I feel just the overall carb restriction is a much better gage.

A new study has come out No effect of a diet with a reduced glycemic index on satiety, energy intake and body weight in overweight and obese women. Two of my favorite bloggers have gone head to head on their interpretation of the findings.

Weight of the Evidence: Glycemic Index Doesn't Matter Much in Overall High-Carb Diet
Junkfood Science: Carbs humbug? — Are carbs really fattening?

Check them both out for all the info on this study.

Dr Barry groves sums up my feelings on how usless the GI Index really is here:

GI Blues: The GI Diet - Second Opinions

You will be told that white bread is high-GI and that wholemeal bread is low-GI, but the difference between their GIs is only 2: white bread is 71; wholemeal is 69. Big deal. By the way, the only whole-wheat bread made in the UK which is listed in the official International GI data is one made by Ryvita Co Ltd. This has a GI of 74 – which is higher than white bread! Another problem is that the same food, made by the same manufacturer, but in a different plant can have widely differing GIs. Take Kellogg's All-Bran, for example, which has a GI of 30 in Australia, 38 in the USA and 51 in Canada. I have no idea what the GI of Kellogg's All-Bran is in Britain as it hasn't been tested.
WTH!!! Read on.....

And there are some strange anomalies. For example, you might think that foods containing sugar would have a higher GI than the same food made without sugar. But Banana cake, made with sugar is 47, while Banana cake, made without sugar is 55.

Then the way a food is cooked or processed also makes a difference to its final glycaemic index, according to a trial conducted at Department of Dietetics, Queen Elizabeth Hospital in Hong Kong.

And there is a last problem as far as diabetics are concerned. The GI of fructose (fruit sugar) is 22, very much lower than sucrose (table sugar) at 64, yet fructose is far more damaging to a diabetic's health than sugar. To sum up, the Glycaemic Index is a very weak index which is over simplified, over hyped, and over sold. While it may have some use in a clinical setting, it is really of very limited use to the general public.
And here is the real clincher for me----and should be for everyone---so take note...

What matters as far as your body is concerned is not the GI of a carbohydrate, but the total amount. A hundred grams of carbohydrate is a hundred grams of carbohydrate whatever its GI is.
That about sums it up.....just count the carbs....bottom line....PERIOD....end of story.


Anonymous said...

Carbs are not evil or magically fattening. ALL calories affect glucose/insulin -- unless you're a diabetic, it's not going to hurt you.

BamaGal said...

Anonymous---I beg to differ with you. But carbs are evil and they are what makes fat. Carbohydrates are what determines insulin response in the body.

Also human bodies are not hard wired to process carbohydrates effectively. We are meant to live on mainly meat. There are essential fatty acids(fat) and essential amino acids(protein) but no essential carbs.

Try reading Gary Taubes book---"Good Calories, Bad Calories", then get back to me.

Medusa said...

Bama, I followed the "GI Diet" ( for one year and lost a whopping total of 4 pounds. I followed the diet to a "T" and didn't cheat once, eating only the "Green Light" foods recommended on the GI diet.

I finally gave up this past January, and re-started Atkins, the only diet that had worked for me in the past. I have lost 50 pounds since January 2007 on Atkins and have just reached goal. Atkins is the ONLY diet that works.

And lowering carbs is the ONLY way to lose weight.

Great post, Bama!