[BIGGUNZ401]

okay is it true, that some fruits are simple carbs and some are complex carbs? The lower the gi value would make it a complex carb right?? The more I read up on this topic the more it gets confusing..thanks again

[Nitrox]

Simple/complex refers to the carbohydrate molecular structure. Unfortunately this has little to do with where a particular carb lies on the glycemic index.

Fructose is the main carbohydrate that is found in fruit. It is a simple carb (aka a sugar) but it one of the lowest on the GI. Maltodextrin is a complex carb but is very high on the GI.

People who use complex/simple to define good/bad carbs are using obsolete information.

[2RIIPPED]

Originally Posted by Nitrox

Simple/complex refers to the carbohydrate molecular structure. Unfortunately this has little to do with where a particular carb lies on the glycemic index.

Fructose is the main carbohydrate that is found in fruit. It is a simple carb (aka a sugar) but it one of the lowest on the GI. Maltodextrin is a complex carb but is very high on the GI.

People who use complex/simple to define good/bad carbs are using obsolete information.

Thats right on the money.

[krogtaar]

i thought that glycemic index was not necisarily important, and that the insulin response was what was important in carbs. there are a few posts by alan aragorn on bodybuilding.com that i believe support this. (for example milk has other stuff that raises insulin)

also, i believe the type of sugar is important (glucose is better than fructose or lactose because it is best absorbed by muscle)

please correct if wrong

[rpen22]

I think you're referring to the point that the glycemic index doesn't necessarily help unless you are eating that single food by itself. The Glycemic index doesn't take into account the other foods(in a meal) being eaten at the same time, which will alter the total insulin response.

Also, certain fruits have a lower GI due to fiber content I believe.

[Nitrox]

Originally Posted by krogtaar

i thought that glycemic index was not necisarily important, and that the insulin response was what was important in carbs. there are a few posts by alan aragorn on bodybuilding.com that i believe support this. (for example milk has other stuff that raises insulin)

also, i believe the type of sugar is important (glucose is better than fructose or lactose because it is best absorbed by muscle)

please correct if wrong

The glycemic index by itself does not tell the whole picture but is far from being useless. It is a measure for how carbohydrate affects blood sugar which then can trigger an insulin response. Since protein and fat are not carbs, the GI does not apply to them however, both can also increase blood sugar and insulin levels by alternate mechanisms. Insulin response testing is more involved so insulin index data is more limited.

I have also seen the claims that glucose is a superior carb to fructose and galactose for muscle. The logic is that since the latter first have to be metabolized into glucose by the liver that the suggestion is that the newly created glucose will be stored as liver glycogen. As opposed to glucose which is absorbed directly into the bloodstream where it can be used by muscle.

This doesn't make sense to me. I can personally attest that fructose and lactose do increase blood sugar levels - they just take longer than straight glucose but the energy will be available to muscle tissue.

[BIGGUNZ401]

thanks everyone for the replies.

[rpen22]

Originally Posted by Nitrox

This doesn't make sense to me. I can personally attest that fructose and lactose do increase blood sugar levels - they just take longer than straight glucose but the energy will be available to muscle tissue.

I'm pretty sure fructose doesn't use insulin as a transporter, so most of it is transported with a different carrier protein(GLUT5?) and metabolized in the liver into liver glycogen as opposed to muscle glycogen.

[Nitrox]

Originally Posted by rpen22

I'm pretty sure fructose doesn't use insulin as a transporter, so most of it is transported with a different carrier protein(GLUT5?) and metabolized in the liver into liver glycogen as opposed to muscle glycogen.

Then why, as a diabetic, do I have to take insulin even when I eat fruit?

Just because fructose is metabolized in the liver it does not mean that it is locked in there. If glycogen stores are full or if the body is energy deficient, it will be released in to the blood stream (energy hub) and stored elsewhere (muscle glycogen, fat, etc.) or used for energy.

[rpen22]

Originally Posted by Nitrox

Then why, as a diabetic, do I have to take insulin even when I eat fruit?

Just because fructose is metabolized in the liver it does not mean that it is locked in there. If glycogen stores are full or if the body is energy deficient, it will be released in to the blood stream (energy hub) and stored elsewhere (muscle glycogen, fat, etc.) or used for energy.

I'm not saying that it doesn't at all elevate blood glucose, I'm just saying I believe that the reason it isn't primarily stored as skeletal muscle glycogen is because it doesn't use insulin as a transporter.

I'm not saying you're wrong, I'm just explaining what I thought/think to be true.

[pistonpump]

i thought this was questions about gixxer,nycste,tripdog,and trauma....



i didnt read the thread but arent fruits simple carbs?

[Nitrox]

Originally Posted by pistonpump

i thought this was questions about gixxer,nycste,tripdog,and trauma....



i didnt read the thread but arent fruits simple carbs?

First you call them fruits, now you call them simple. Methinks some whoopass be comin.

[pistonpump]

Originally Posted by Nitrox

First you call them fruits, now you call them simple. Methinks some whoopass be comin.

by fruits?.....or by fairies?

[pudzian2]

I think it may be beneficial to make an organized list\chart of some sort by the end of this thread that helps compare common fruits and their glycemic index vs. insulin response, blood glucose elevation response vs. simple\complex.

The list can then probably have other carb sources added to it.

the glycemic index is useful, but such a comparison would make things a lot more accurate for determining which fruits are best if eaten throughout the day and which fruits\other carbs\sugars are best for say Post Workout and the desired insulin response at that time.

[prld2gr8ns]

Originally Posted by Nitrox

Then why, as a diabetic, do I have to take insulin even when I eat fruit?

Just because fructose is metabolized in the liver it does not mean that it is locked in there. If glycogen stores are full or if the body is energy deficient, it will be released in to the blood stream (energy hub) and stored elsewhere (muscle glycogen, fat, etc.) or used for energy.

Several things can contribute to why you see a rise in BG after consuming fructose. 1. It's one of the most adequate carb sources for replenishing liver glycogen stores, allowing for increase rates of glycogenolysis and thus adequate release of glucose into the bloodstream. 2. In the liver fructose is rapidly acted upon by the fructase and F1P enzymes which converts the simple sugar into intermediates of both the glycolytic, and gluconeogenic pathways. Which sets up yet another path for increasing glucose levels via gluconeogeneisis and yet more glycogenesis.

Fructose never leaves the liver as fructose(hans GLUT5 presence), it either undergoes glycolytic conversion or lipogenic conversion. The latter being an uninhibited and efficient trait. Keep in mind that pathway change over is regulated by liver glycogen stores, thus if liver glycogen is full, regardless of muscle glycogen levels, turnover ratio's are going to start favoring lipogenesis. It's effects on muscle glycogen are a secondary charateristic by the aformentioned pathways.