How Useful Is The Glycemic Index As A Diet Guide?


The glycemic index (GI) was created within the 1980s to assist individuals handle or forestall kind 2 diabetes. The thought is that figuring out a meals’s GI rating helps individuals make good meals decisions. Since then, the index has additionally been used as the idea for a lot of weight-loss packages. 

The downside with the “GI diet” is that many individuals do not perceive precisely what the glycemic index measures. And that may result in misunderstandings of easy methods to use it to decide on the best meals—particularly the best carbohydrates. 

I am right here to set the report straight.

The GI-Diet Theory

The glycemic-index eating regimen relies on the concept that too many carbohydrates from the improper sorts of meals can introduce an excessive amount of glucose within the physique. Excess glucose results in the manufacturing of extra insulin, which may result in dizziness, low vitality, and intense starvation, which may in the end result in weight achieve. 

As the idea goes, people who find themselves making an attempt to lose weight ought to keep away from carbs that trigger an excessive amount of glucose to enter their system too quick. These are meals with excessive GI scores. By selecting carbs that metabolize into glucose extra slowly—these with low GI scores—you possibly can keep away from the low vitality and starvation pangs that derail many a dieter’s greatest intentions.

How Useful Is The Glycemic Index As A Diet Guide?

GI Score Is Not Enough

One downside with the glycemic index, although, is that it would not replicate how a lot precise sugar is in every carb kind. In some instances, a carbohydrate with a excessive GI rating might not comprise a lot sugar, nevertheless it nonetheless causes a fast rise in blood glucose—and vice versa. GI scores alone do not present sufficient data to make good meals decisions.

Two research confirmed the issue with counting on GI rating alone. The first, printed within the American Journal of Clinical Nutrition, discovered that counting on the GI to determine which carbs to devour is not essentially a good suggestion—particularly while you’re making an attempt to reduce weight. As a part of this 18-month research, greater than 200 girls had been divided into 2 teams. One group ate a calorie-restricted eating regimen of principally low-GI carbs (slower-digesting carbs); the opposite group ate principally high-GI carbs (faster-digesting carbs). You may suppose that the “better” carbs—the low GI ones—would pace weight reduction. But on the finish of the research, there was no vital distinction in how a lot weight every group was capable of lose.[1]

How Useful Is The Glycemic Index As A Diet Guide?

Another research, this 1 printed within the American Journal of Clinical Nutrition, in contrast the impact of high-GI corn flakes to low-GI bran flakes.[2] The conclusion was the identical: no distinction between bran flakes and corn flakes, this time on their preliminary impacts on glucose ranges following a meal. 

In reality, what you may think about the “healthier” bran flakes triggered a barely sooner rise in blood glucose instantly following the meal. It wasn’t till 30 minutes later that the rise in blood glucose ranges brought on by the bran-flake cereal levelled out extra (which is what led to bran flakes having a decrease GI rating than corn flakes). 

What Matters Besides GI Score?

If you are pondering of utilizing GI scores to decide on carbohydrates in your eating regimen, consider a number of components that may have an effect on the way in which your physique processes these carbs. It all goes again to that situation of avoiding the sharp spikes and drops in blood glucose ranges and the insulin manufacturing they will trigger.

First, it is extra essential to pick meals primarily based on their nutrient density (the quantity of vitamins, minerals, and fiber they comprise per chunk) relatively than their GI rating. And in relation to weight reduction, select carbs that enable you devour fewer energy than you are burning—and in a manner that is sustainable. 

Second, 1 approach to decelerate the discharge of glucose into the blood is by slowing down your digestion. Finding methods to digest meals extra slowly reduces the speed at which your physique turns carbs into glucose—and reduces these starvation pangs that have you ever raiding the fridge at midnight.

How Useful Is The Glycemic Index As A Diet Guide?

Protein: Slow down digestion by including protein to a meal, akin to by placing milk in your cereal. This is partly as a result of protein-rich meals stimulate launch of a hormone known as glucagon, the consequences of that are the alternative of these induced by insulin.[3,4]

Fat: Try including fats to your meal, akin to placing peanut butter on bread, to gradual digestion.

Keep all of those “adjustments” in thoughts as you look to the glycemic index to information your meals decisions. By making sensible meals selections, you possibly can decelerate your digestion, scale back your urge for food, and nonetheless have the sustainable vitality it is advisable be lively and reduce weight.

  1. Sichieri, R., Moura, A. S., Genelhu, V., Hu, F., & Willett, W. C. (2007). An 18-mo randomized trial of a low-glycemic-index eating regimen and weight change in Brazilian girls. The American Journal of Clinical Nutrition, 86(3), 707-713.
  2. Schenk, S., Davidson, C. J., Zderic, T. W., Byerley, L. O., & Coyle, E. F. (2003). Different glycemic indexes of breakfast cereals will not be on account of glucose entry into blood however to glucose elimination by tissue. The American Journal of Clinical Nutrition, 78(4), 742-748. 
  3. Aronoff, S. L., Berkowitz, Ok., Shreiner, B., & Want, L. (2004). Glucose metabolism and regulation: past insulin and glucagon. Diabetes Spectrum,17(3), 183-190.
  4. Claessens, M., Saris, W. H., & van Baak, M. A. (2008). Glucagon and insulin responses after ingestion of various quantities of intact and hydrolysed proteins. British Journal of Nutrition, 100(01), 61-69.

(Editor references)

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