Comments on: Turning a blind eye to GI

By: Bill Shrapnel

Bill Shrapnel — Wed, 13 Jun 2012 02:19:38 +0000

Hi James. Long live scepticism! In relation to GI, I sat on the fence for 15 years – there just wasn’t enough evidence to convince me. But with the new studies I reviewed in my blog I think GI has to at least be considered. The evidence that GI is related to health is stronger than that for sugar and health. I can’t see how you can base dietary guidelines around sugar but not GI. It should be both or neither. Not sure about your idea about GI being a proxy for overall diet quality. Fruits generally have low GI; many wholegrains have high GI – there are many anomalies. That’s what makes carbohydrate quality such a challenging concept. Regards, Bill

By: polo la martina

polo la martina — Wed, 23 May 2012 08:56:32 +0000

I truly enjoyed reading it. Waiting for some more great stuff like this from you in the coming days.

By: James Krieger

James Krieger — Mon, 21 May 2012 05:26:41 +0000

I remain skeptical of the utility of the GI and its association with chronic disease. Most people consume carbohydrates in combination with protein and fat, which can dramatically change the GI of a food. Stanhope et al showed the calculation of the GI for mixed meals to be unreliable, overestimating the true GI by 22-50%…this was with small amounts of protein and fat in the meal. Fabricatore et al showed the GI to have some predictive value in terms of predicting some blood glucose metrics in overweight and obese people, but the predicting power was weak and the GI could only account for 10-18% of the variance. The individual data was all over the place in this study; some days with the highest glycemic diets scored the best on metrics of glycemia. In the Diogenes study, they only achieved a 4.7 point difference in GI. While much of the data on GI might be statistically significant, but I question the biological significance. I think GI is more of a proxy for overall diet quality (i.e., a diet rich in whole fruits and vegetables) , which is why you see associations with chronic disease.