T Nation

Glucose Index...Does it really matter?

Ok, does it really matter if you consume a carb that has a 40 index rating or an 80 index rating…as long as you are consuming adequate protein and fats with it? Example 25 grams of carbs with a rating of 40, combined with 40 grams of whey/cassein and 5-10 grams of flax oil. As opposed to the same meal with an 80 rating. How about if you used ground flax seed in this meal/drink. So, does it really matter? Should one, buy a glucometer and test themselves? If so, how often? Should it be repeated a few days later and averaged ,or is that necessary? Ok, I can hardly wait for the answers to fly on this one.

Yes, glycemic index does matter. Many things can affect the GI when there is a combination of foods being eaten. Fiber, fat, the type of sugar (fructose is lowest), all can affect the total GI of a meal. So, if you consume a carb with a GI of 40, combining it with some fat and fiber would lower it even further. Going back to why it matters, if you consume a 2,000 calorie diet with high GI foods and a 2,000 calorie a day diet consisting of low GI foods, you’ll do better in terms of fat loss, muscle mass, and satiety with the low GI diet. The reason being has to do with the ever important pancreatic hormone we call insulin. Low GI foods will cause a smaller and more consistent release of insulin. The benefits of this include increased insulin sensitivity, fat utilization, and too many others to list. I have an article, that should be out very soon here, which includes a section on the benefits of low GI foods. Stay tuned Bodz!

The flip side to Cy’s point is that high G.I. foods can be beneficial under certain circumstances also. Post-workout meals can be high in G.I. carbs and this will help push more carbs and amino acids into the muscles. If you consume a carb source with a G.I. of 80-100, you will enhance anabolism and recovery relative to the carb source with a G.I. of 40. Two rules of thumb, 1) high G.I. for recovery 2) low G.I. to stabilize blood sugar and enhance lypolysis. I think the point Cy was trying to make is that you don’t want to eat high G.I. foods all the time. You will end up reducing insulin sensitivity and falling down that slippery slope toward NIDDM.

Well said Steve, couldn’t have put it any better myself. Well maybe…Just kidding!