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
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.
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
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.
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.
thanks everyone for the replies.
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 you're wrong, I'm just explaining what I thought/think to be true.
i thought this was questions about gixxer,nycste,tripdog,and trauma....
i didnt read the thread but arent fruits simple carbs?
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.
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.
~ Nothing can kill the Grimace!!
Glycemic Index does not accurately predict Insulin Score. However, the quantity of food consumed is a better indicator of Insulin Response
GI is simply a measure of how high the blood sugar rises in response to a given amount of CHO from various sources compared to a standard food (usually white bread or glucose). For example, carrots and potatoes have about the same high GI as sugar and white bread. However, carrots have only 195 calories per pound and a boiled potato has about 450 calories per pound while bread contains around 1250 calories per pound and sugar contains 1725 calories per pound. So the volume of food must increase dramatically for foods with a lower calorie density to be fed at the same CHO level. Since gastric expansion increases the rate of gastric emptying and CHO can only be absorbed after it leaves the stomach, this methodology creates a bias against lower calorie dense foods. Foods that lead to a higher osmolarity in the stomach can delay gastric emptying and this may also slow their absorption and lower the glycemic response. The reason sports drinks don�t have a high concentration of sugar is that it would delay gastric emptying and slow the absorption of water.
The Insulin Score, (IS) or insulin index, is a measure of insulin output in response to a given caloric amount of various foods. Among foods with little fat or protein, the GI correlates fairly well with the IS. Dietary fat delays gastric emptying so any CHO consumed with a lot of fat usually results in a lower GI but because the fat magnifies the insulin output to a given rise in blood sugar, the IS is generally much higher than would be predicted based on the GI. For example, ice cream with its high fat content and high osmolarity has a fairly low GI, much lower than potatoes, rice or carrots. However, dietary fat greatly magnifies the insulin response to a given amount of CHO so the IS for ice cream is only slightly lower than that of potatoes and actually higher than white rice despite its much lower glycemic index. Dietary protein, like fat, also causes more insulin to be released; foods with no CHO at all cause a fairly substantial insulin response even though they have little effect on blood sugar. It should be clear then that GI does not accurately predict the IS when foods vary considerably in their macronutrient composition and/or ED.
The satiety index (SI) is a relatively new concept that measures how full or satiated people feel after consuming a given calorie load from a variety of foods. It is measured by asking people to rate how satiated they are after a meal and by how much food they will eat after a 2-hour delay after consuming the test food. So a high SI food would leave people more satisfied after eating a set amount of calories and they would also eat less 2 hours later when given something else to eat presumably because they were still less hungry. It seems likely that a diet made up of higher SI foods would likely lead to less hunger and a lower calorie intake. The notion that high GI foods lead to obesity ultimately rests on the assumption that GI equals Satiety Index (SI). It turns out that the highest SI food tested was the potato which is also one of the highest GI foods. Clearly then the presumption that all high GI foods lead to overeating and obesity is not correct. Therefore, the theory that high GI foods invariably lead to excessive insulin output which in turn prevents fat burning and promotes fat storage and obesity is of little scientific merit. In fact, insulin output in response to a meal correlates far better with total calories consumed than it does with the relative GI of the various foods in that meal.
sorry guys, don't know why i posted all this. i guess for informative purposes only.