More on the Glycemic Index and the Insulin Index

December 13th, 2009 by

What else can change the glycemic index of a food? How about how ripe the food is as well as cooking it. Both of these factors function to increase a given carbohydrate’s glycemic index. Once again – can we really expect to think that just cooking a food or a change in food ripeness changes the resultant physique effects of that food? Come on. So if I eat a riper banana it’s worse for my fat-loss goals because it has a higher GI value? That’s a rhetorical question as I’m hoping the answer is obvious.

Back to our white potatoe. Ever heard of the Satiety Index? Well, in short, it’s a measure of the satiation-inducing effect of a given food. And guess what? Potatoes are right at the top. Way at the top. Yep, those high GI white potatoes. White rice is another food that ranks high on the Satiety Index … yet also high on the Glycemic Index. The puzzlement comes from the fact that the claim has always been that low GI foods are also high satiety foods. Such doesn’t appear to be always the case. The importance of satiety in the face of restricted calories is clearly a very important aspect of food selection and subsequent dieting success. As we all know, hunger tends to pop up more and more when we’re restricting calories and eating less than we habitually do, so any strategies we can come up with to help alleviate that annoying hunger are worth their weight in gold. One such strategy is to choose foods higher on the Satiety index … yes even though some might be higher on the Glycemic Index. Again why? Because dietary compliance/adhering to your plan is one big key to success and successfully reducing hunger is likely to help keep you on plan.

How about the Insulin Index? The Insulin Index is a measure of the actual insulin response to a given food. Again, GI proponents often associate low GI foods with ‘high quality carbohydrates’ and subsequently, reduced insulin response, which is technically what GI advocates are trying to control in the first place (insulin misconceptions – that’s another topic for another time). But again, such is not necessarily the case. The last I looked (which was a while ago) there were only 38 foods tested on the Insulin Index so it’s far from an exhaustive list at this point, but there are definitely some interesting realizations even with such a limited number of tested foods. For example, some foods that fall low on the Glycemic Index – things like milk for example – ranked very high for insulin response. Not what you’d expect if you believed that low GI = ‘good carb’ = low blood sugar elevation = low insulin response. Right? Previously I mentioned that the addition of fat to a carbohydrate meal generally lowers the GI due to a reduction in the rate of gastric emptying. Well, interestingly enough, the addition of fat, saturated fat in particular, raises the insulin response significantly. More GI irrelevance.

To drive another nail in the GI relevance coffin, the overwhelming conclusion looking at human weight-loss trials is that there is no significant difference in weight loss whether one follows a low glycemic index diet, or a high glycemic index diet. It just doesn’t matter.

In the end, the key is still overall calories first and foremost and your macronutrient (protein, carbohydrate, and fat) totals at the end of the day. There’s little need to pay much beyond a passing amount of attention to the Glycemic Index. It’s relevance to physique enthusiasts is non-existent.

BACK: The Hoax of the Glycemic Index

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