The Glycemic Index

The Glycemic Index (GI) - Key To Fat Loss Or Just Another Diet Gimmick
By Tom Venuto, NSCA-CPT, CSCS
www.burnthefat.com

The glycemic index (GI) is a scale from 1 to 100 that measures how quickly carbohydrate foods are broken down into glucose. The original purpose for the glycemic index was to help diabetics keep their blood sugar under control. The glycemic index has recently attracted a lot of attention in the bodybuilding, fitness and weight loss world and has even become the central theme in numerous best-selling diet books as a method to choose the foods that are best for losing weight.

According to advocates of the glycemic index system, foods that are high on the GI scale such as rice cakes, carrots, potatoes, watermelon or grape juice are "unfavorable" and should be avoided because high GI foods are absorbed quickly, raise blood sugar rapidly and are therefore more likely to convert to fat or cause health problems.

Instead, we are urged to consume carbohydrates that are low on the GI scale such as black eye peas, barley, old fashioned oatmeal, peanuts, grapefruit, apples and beans because they do not raise blood sugar as rapidly.

While the GI does have some useful applications, such as the use of high GI foods or drinks for post workout nutrition and the strong emphasis on low GI foods for those with blood sugar regulation problems, there are flaws in strictly using the glycemic index as your only criteria to choose carbs on a weight loss program.

For example, the glycemic index is based on eating carbohydrates by themselves in a fasted state. If you are following effective principles of fat-burning and muscle building nutrition such as those outlined in my Burn The Fat, Feed The Muscle (BFFM) e-book (www.burnthefat.com), you should be eating small, frequent meals to increase your energy, maintain lean body mass and optimize metabolism for fat loss.

However, since the glycemic index of various foods was developed based on eating each food in the fasted state, the glycemic index loses some of its significance. you should be eating small, frequent meals to increase your energy, maintain lean body mass and optimize metabolism for fat loss. However, since the glycemic index of various foods was developed based on eating each food in the fasted state, the glycemic index loses some of its significance.

In addition, when you are on a diet program aimed at improving body composition (losing fat or gaining muscle), you will usually be combining carbs and protein together with each meal for the purposes of improving your fat to muscle ratio. When carbs are eaten in mixed meals that contain protein and some fat, the glycemic index loses even more of its significance because the protein and fat slows the absorption of the carbohydrates (as does fiber).

Mashed potatoes have a glycemic index near that of pure glucose, but combine the potatoes with a chicken breast and broccoli and the glycemic index of the entire meal is lower than the potatoes by itself.

Rice cakes have a very high glycemic index, but if you were to put a couple tablespoons of peanut butter on them, the fat would slow the absorption of the carbs, thereby lowering the glycemic index of the combination.

A far more important and relevant criteria for selecting carbs for weight loss - as well as all your other foods, proteins and fats included - is whether they are natural or processed. To say that a healthy person with no metabolic disorders should completely avoid natural, unprocessed foods like carrots or potatoes simply because they are high on the glycemic index is ridiculous.

I know many bodybuilders (myself included) who eat high glycemic index foods such as white potatoes every day right up until the day of a competition and they reach single digit body fat. How do they do it if high GI foods “make you fat?” It’s simple – high GI foods DON’T necessarily make you fat – choosing natural foods and burning more calories than you consume are far more important factors. Although it’s not correct to say that all calories are created equal, a calorie deficit is the most important factor of all when fat loss is your goal.

The glycemic index is clearly not a "gimmick" and should not be completely disregarded, as it is a definitely a legitimate nutritional tool. Is it a good idea to eat low GI foods in general? Sure. Is eating high GI foods after your workouts a good idea? Absolutely. But diet programs which hang their hats on glycemic index alone as the “miracle solution” are just another example of how one single aspect of nutrition can be used as a "hook" in marketing and said to be the "end all be all" of fat loss, when it's really only one small piece of the puzzle.

Eating Low glycemic index foods alone does NOT guarantee you will lose fat. You have to take in the bigger picture, which includes calories/energy balance, meal timing and frequency, macronutrient composition, choice of processed versus refined foods as well as how all these nutritional factors interact with your exercise program.

For more information on carbohydrates and the glycemic index, and for a balanced, gimmick-free look at all aspects of fat-burning nutrition, be sure to visit the Burn The Fat, Feed The Muscle website at: www.burnthefat.com

About the Author:

Tom Venuto is a lifetime natural bodybuilder, an NSCA-certified personal trainer (CPT), certified strength & conditioning specialist (CSCS), and author of the #1 best-selling e-book, "Burn the Fat, Feed The Muscle.” Tom has written more than 200 articles and has been featured in print magazines such as IRONMAN, Australian IRONMAN, Natural Bodybuilding, Muscular Development, Exercise for Men and Men’s Exercise, as well as on hundreds of websites worldwide. For information on Tom's Fat Loss program, visit: www.burnthefat.com

Nutrition: Study Links Sugary Drinks to Teenagers' Weight

Okay, so here I go again. I ran across this article on google this morning and I really tired to avoid reading it, but how could I resist.

Here is the link to the whole article.
http://www.nytimes.com/2006/03/07/health/07nutr.html

Do we (any of us) really need some sort of study to tell us that drinking lots of sugar filled drinks will make us fat....

C'mon...

I'm thinkin maybe a slow news day. Whats that all about? They actually did a study...

"The researchers, led by Cara B. Ebbeling of Children's Hospital Boston, found that the teenagers' consumption of the high-calorie drinks went down by about 80 percent during the study and that the teenagers who had been the most overweight had significant reductions in their body mass indexes at the end of the 25 weeks."

No really... Go figure no more sugary drinks and people lose weight... I'm suprised


C'mon folks this isn't news, we've always known this.

The Evils of Sugar.

I know I'm on a rant here about sugar and the whole G.I. thing....

I think its my mission to get more people to look at sugar as it truly is... A Drug.

Yes..... I said it... it is a drug.

Sugar does more then just sweeten our foods, its used as a pick me up to make us feel better and when we burn it all up... we head right back to the kitchen or the corner convenience store to get another fix.

Feeling depressed eat some chocolate, a candy bar, some hard candy any sugary food will work.

It actually works for most things..... hunger, feeling sleepy, feeling drained etc.

Sugar is not about nutrition its about getting a fix. Think about it...........

So whats up with corn syrup..... Let me rephrase that... High Fructose Corn Syrup....

That stuff is like high octane sugar. Now go to your pantry or your cupboard and read the labels on some of you favorite soups, canned goods or drinks.

You bet....

Corn syrup.

The thing that really gets me is how hard it is to find canned corn that doesn't have corn syrup added to it. Whats up with that????????????

High Fructose corn syrup is made through a complicated process of breaking down corn starch into glucose and then the glucose is broken down into fructose using a system primarily composed of three different genetically altered enzymes. The process involved in refining and distributing corn syrup is cheaper and more efficient then sugars refined from cane or beets. High fructose corn syrup is extremely soluble and mixes well in many foods. It is cheap to produce, sweet and easy to store. It’s used in everything from bread to pasta sauces to bacon to beer as well as in health products like protein bars and natural sodas. This brings to point my issue with corn syrup in all the foods we eat, in every can around every corner.

Every cell in our bodies has the ability to break down glucose but fructose is handled solely by the liver. In research involving rats as the primary subjects... the rats were feed diets high in corn syrup.

"The researchers wanted to know whether it was the fructose or the glucose moiety that was causing the problems. So they repeated their studies with two groups of rats, one given high amounts of glucose and one given high amounts of fructose. The glucose group was unaffected but the fructose group had disastrous results. The male rats did not reach adulthood. They had anemia, high cholesterol and heart hypertrophy—that means that their hearts enlarged until they exploded. They also had delayed testicular development. Dr. Field explains that fructose in combination with copper deficiency in the growing animal interferes with collagen production." (1)

Other research on sugars indicates that excess sugar depresses immunity, sours behavior, attention and learning.

Any sugars (glucose, fructose or sucrose) should be taken in moderation and anyone living a healthy life style should consider every morsel they put in their mouths.


Okay.....I'm done ranting now.

(1)Weston A. Price Foundation Board Member Linda Forristal is the author of Ode to Sucanat (1993) and Bulgarian Rhapsody (1998). Visit her website at www.motherlindas.com.

The Glycemic Index.

The Glycemic Index the latest and greatest dieting secret.

Ohhhhhhh my. I remember reading about the G.I. when I was in grade school. Now all of a sudden its like... Poof out of no where we have something new to consider.

I remember being in an antique shop several months ago... On one of the tables was a book printed around the 1940 outlining the evils of sugar. Hmm what's that all about?

Did I mention that roman athletes often ate diets high in protein and low in sugars and carbs?

Just one piece of advice. Read the labels on everything you eat. Even if the label contains the words healthy or low fat.

From Wikipedia

Glycemic Index

The Glycemic Index (also glycemic index, GI) is a ranking system for carbohydrates based on their immediate effect on blood glucose levels. It compares carbohydrates gram for gram in individual foods, providing a numerical, evidence-based index of postprandial (post-meal) glycemia. The concept was invented by Dr. David J. Jenkins and colleagues in 1981 at the University of Toronto.

The glycemic index of a food is defined by the area under the 2 hour blood glucose response curve (AUC) following the ingestion of a fixed portion of carbohydrate (usually 50 g). The AUC of the test food is divided by the AUC of the standard (either glucose or white bread) and multiplied by 100. The average GI value is calculated from data collected in 10 human subjects. Both the standard and test food must contain an equal amount of available carbohydrate. The result gives a relative ranking for each tested food (Brouns et al, 2005).

Carbohydrates that break down rapidly during digestion have the highest glycemic indices. An increased blood glucose response occurs very quickly. Carbohydrates that break down slowly, releasing glucose gradually into the blood stream, have a low glycemic index. A lower glycemic index suggests slower rates of digestion and absorption of the sugars and starches in the foods and may also indicate greater extraction from the liver and periphery of the products of carbohydrate digestion. Additionally, a lower glycemic response equates to a lower insulin demand, better long-term blood glucose control and a reduction in blood lipids.

Glycemic index values for different foods are calculated by comparing measurements of their effect on blood glucose with an equal carbohydrate portion of a reference food. The current scientific validated methods use glucose as the reference food. Glucose has a glycemic index value of 100. This has the advantages in that it is universal and it results in maximum GI values of approximately 100.

Glycemic Index of Foods

GI values can be interpreted intuitively as percentages on an absolute scale and are commonly interpreted as follows:

* Low GI - less than 55
* Intermediate GI - between 56 and 69
* High GI - higher than 70

A low GI food will release energy slowly and steadily and is appropriate for diabetics, dieters and endurance athletes. A high GI food will provide a rapid rise in blood sugar levels and is suitable for post-endurance exercise energy recovery. Previously, white bread was sometimes used as a reference food (if white bread = 100, then glucose = 140). For people whose staple carbohydrate source is white bread, this had the advantage of conveying directly whether replacement of the dietary staple with a different food would result in faster or slower blood glucose response. The disadvantages with this system were that the reference food was not well-defined, and the GI scale was culture dependent.

The glycemic effect of foods depends on a number of factors such as the type of starch (amylose vs amylopectin), physical entrapment of the starch molecules within the food, fat content of the food and increased acidity of the meal - adding vinegar for example, will lower the GI. The presence of fat or dietary fibre can inhibit carbohydrate absorption, thus lowering the GI. Unrefined breads with higher amounts of fibre generally have a lower GI value than white breads but, while adding butter or oil will lower the GI of bread, the GI ranking does not change. That is, with or without additions, there is still a higher blood glucose curve after white bread than after a low GI bread such as pumpernickel.

The glycemic index can only be applied to foods with a reasonable carbohydrate content, as the test relies on subjects consuming enough of the test food to yield about 50 g of available carbohydrate. High fat or high protein foods such as meat, eggs, nuts and cheese have a negligible GI. Furthermore, because many fruits and vegetables (but not potatoes) contain very little carbohydrate per serving, they have very low GI values and are regarded as "free" foods. This also applies to carrots, which were originally and incorrectly reported as having a high GI (Brand-Miller et al, 2005). Alcoholic beverages have been reported to have low GI values, however it should be noted that beer has a moderate GI. Recent studies have shown that the consumption of an alcoholic drink prior to a meal reduces the GI of the meal by approximately 15% (Brand-Miller, in press).

Disease Prevention

Several lines of recent scientific evidence have shown that individuals who followed a low GI diet over many years were at a significantly lower risk for developing both type 2 diabetes and coronary heart disease. High blood glucose levels or repeated glycemic "spikes" following a meal may promote these diseases by increasing oxidative damage to the vasculature and also by the direct increase in insulin levels (Temelkova-Kurktschiev et al, 2000). In the past, postmeal hyperglycemia has been a risk factor mainly associated with diabetes, however more recent evidence shows that postprandial hyperglycemia presents an increased risk for atherosclerosis in the non-diabetic population (Balkau et al, 1998).

Weight Control

Recent animal research provides compelling evidence that high GI carbohydrate is associated with increased risk of obesity. In human trials, it is typically difficult to separate the effects from GI and from other potentially confounding factors such as fibre content, palatability, and compliance. In the study (Pawlak et al, 2004), male rats were split into a high and low GI group over 18 weeks while mean bodyweight was maintained. Rats fed the high GI diet were 71% fatter and 8% less lean than the low GI group. Postmeal glycemia and insulin levels were significantly higher and plasma triglycerides were three-fold greater in the high GI fed rats. Furthermore, pancreatic islet cells suffered “severely disorganised architecture and extensive fibrosis”. The evidence in this study showed that continued consumption of high glycemic index carbohydrates would likely have led to the development of severe metabolic abnormalities.

Criticism

The glycemic index has been criticised for the following reasons:

* the GI of a food varies depending on the kind of food, its ripeness, the length of time it was stored, how it was cooked, its variety (potatoes from Australia, for example, have a much higher GI than potatoes from the United States), and how it was processed or manufactured.

* the GI of a food varies from person to person and even in a single individual from day to day, depending on blood glucose levels, insulin resistance, and other factors.

* the GI of a mixed meal is difficult to predict.

* the GI value is based on a portion that contains 50 grams of carbohydrate only.

* a limited range of data and daily fluctuations in an individualÂ’s glycemic response.

Some of these criticisms can be addressed by taking the Glycemic load into account. This combined approach is, however, somewhat more complicated, and therefore harder to use in giving dietary advice.

Wikipedia information about glycemic index on Answers.com. Wikipedia Copyright © 2005 by Wikipedia. Published by Wikipedia.

Dictionary definition of glycemic index on Answers.com. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company.