Glycemic index diet: What's behind the claims - Mayo Clinic Glycemic index diet: What's behind the claims By Mayo Clinic Staff A glycemic index diet is an eating plan based on how foods affect your blood sugar level. The glycemic index is a system of assigning a number to carbohydrate-containing foods according to how much each food increases blood sugar. The glycemic index itself is not a diet plan but one of various tools — such as calorie counting or carbohydrate counting — for guiding food choices. The term "glycemic index diet" usually refers to a specific diet plan that uses the index as the primary or only guide for meal planning. Unlike some other plans, a glycemic index diet doesn't necessarily specify portion sizes or the optimal number of calories, carbohydrates, or fats for weight loss or weight maintenance. Many popular commercial diets, diet books and diet websites are based on the glycemic index, including the Zone Diet, Sugar Busters and the Slow-Carb Diet. Purpose The purpose of a glycemic index (GI) diet is to eat carbohydrate-containing foods that are less likely to cause large increases in blood sugar levels. The diet is a means to lose weight and prevent chronic diseases related to obesity such as diabetes and cardiovascular disease.

Why you might follow the GI diet You might choose to follow the GI diet because you: Want to lose weight or maintain a healthy weight Need help planning and eating healthier meals Need help maintaining blood sugar levels as part of a diabetes treatment plan The scientific evidence supporting the role of the GI diet in weight loss is mixed. You might be able to achieve the same health benefits by eating a healthy diet, maintaining a healthy weight and getting enough exercise. Check with your doctor or health care provider before starting any weight-loss diet, especially if you have any health conditions, including diabetes. The glycemic index The GI principle was first developed as a strategy for guiding food choices for people with diabetes. An international GI database is maintained by Sydney University Glycemic Index Research Services in Sydney, Australia. The database contains the results of studies conducted there and at other research facilities around the world. A basic overview of carbohydrates, blood sugar and GI values is helpful for understanding glycemic index diets. Carbohydrates Carbohydrates, or carbs, are a type of nutrient in foods. The three basic forms are sugars, starches and fiber.

When you eat or drink something with carbs, your body breaks down the sugars and starches into a type of sugar called glucose, the main source of energy for cells in your body. Fiber passes through your body undigested. Two main hormones from your pancreas help regulate glucose in your bloodstream. The hormone insulin moves glucose from your blood into your cells. The hormone glucagon helps release glucose stored in your liver when your blood sugar (blood glucose) level is low. This process helps keep your body fueled and ensures a natural balance in blood glucose. Different types of carbohydrates have properties that affect how quickly your body digests them and how quickly glucose enters your bloodstream. Understanding GI values There are various research methods for assigning a GI value to food. In general, the number is based on how much a food item raises blood glucose levels in healthy research participants compared with how much pure glucose raises their blood glucose. GI values are generally divided into three categories: Low GI: 1 to 55 Medium GI: 56 to 69 High GI: 70 and higher For example, raw carrots have a GI value of 35.

This means that if you eat enough carrots to consume 1.8 ounces (50 grams) of digestible carbohydrates (sugars and starches), your blood glucose level after eating the carrots will be 35 percent of the blood glucose level after eating 1.8 ounces (50 grams) of pure glucose. Comparing these values, therefore, can help guide healthier food choices. For example, an English muffin made with white wheat flour has a GI value of 77. A whole-wheat English muffin has a GI value of 45. Limitations of GI values One limitation of GI values is that they don't reflect the likely quantity you would eat of a particular food. For example, watermelon has a GI value of 80, which would put it in the category of food to avoid. But watermelon has relatively few digestible carbohydrates in a typical serving. In other words, you have to eat a lot of watermelon to consume the standard test level of 1.8 ounces (50 grams) of digestible carbohydrates.

To address this problem, researchers have developed the idea of glycemic load (GL), a numerical value that indicates the change in blood glucose levels when you eat a typical serving of the food. For example, a 4.2-ounce (120-gram) serving of watermelon has a GL value of 5, which would identify it as a healthy food choice. For comparison, a 2.8-ounce (80-gram) serving of raw carrots has a GL value of 2. Sydney University's table of GI values also includes GL values. The values are generally grouped in the following manner: Low GL: 1 to 10 Medium GL: 11 to 19 High GL: 20 or more Other issues A GI value tells us nothing about other nutritional information. For example, whole milk has a GI value of 31 and a GL value of 4 for a 1-cup (250-milliliter) serving. But because of its high fat content, whole milk is a poor choice for weight loss or weight control. The published GI database is not an exhaustive list of foods, but a list of those foods that have been studied.

Many healthy foods with low GI values are not in the database. The GI value of any food item is affected by several factors, including how the food is prepared, how it is processed and what other foods are eaten at the same time. Glycemic Index Glycemic Index Not all Carbohydrate foods are equal The Glycemic Index (GI) is a relative ranking of carbohydrate in foods according to how they affect blood glucose levels. Carbohydrates with a low GI value (55 or less) are more slowly digested, absorbed and metabolised and cause a lower and slower rise in blood glucose and, therefore insulin levels.﻿ What is the Glycemic Index? The World's Healthiest Foords are health-promoting foods that can change your life. Watch for the launch of our new WHFoods 7-Day Meal Plan on January 23rd! The George Mateljan Foundation is a not-for-profit foundation with no commercial interests or advertising. Our mission is to help you eat and cook the healthiest way for optimal health. What is the Glycemic Index? References What Is the Glycemic Index (GI)?

Glycemic Index (GI) is a measurement carried out on carbohydrate-containing foods and their impact on our blood sugar. GI is a relatively new way of analyzing foods. Previously, most meal plans designed to improve blood sugar analyzed the total amount of carbohydrates (including sugars and starches) in the foods themselves. GI goes beyond this approach, looking at the impact of foods on our actual blood sugar. In other words, instead of counting the total amount of carbohydrates in foods in their unconsumed state, GI measures the actual impact of these foods on our blood sugar. We rank our WHFoods as being very low, low, medium, or high in their GI value. You can find a GI value for each individual food in its food profile. Just go to any food profile and take a look at the DRI%/DV% bar chart that is located towards the beginning of the article. At the top right-hand side of the chart you will find the food's GI value. Why Is GI Important?

Over the past 15 years, low-GI diets have been associated with decreased risk of cardiovascular disease, type 2 diabetes, metabolic syndrome, stroke, depression, chronic kidney disease, formation of gall stones, neural tube defects, formation of uterine fibroids, and cancers of the breast, colon, prostate, and pancreas. Taking advantage of these potential health benefits can be as simple as sticking with whole, natural foods that are either low or very low in their GI value. We've ranking all of our WHFoods as being either high GI, medium GI, low GI, or very low GI to make it easier for you to focus on foods whose GI values fall into the low or very low range (we've also done this for the herbs and spices we include on the website). How Is GI Measured? Typically, a food is consumed in whatever serving size will provide 50 grams (about 1.8 ounces) of available carbohydrates. Available carbohydrates (or avCHOs) are carbohydrates that get readily digested, absorbed, and metabolized by our body.

These carbohydrates have a much greater impact on our blood sugar level than carbohydrates in general because carbohydrates in general include substances that aren't readily digested, absorbed, and metabolized. Insoluble fibers, for example, are carbohydrates that do not have an immediate impact on our blood sugar level because they cannot be readily digested. As a very general way of estimating available carbohydrates in a serving of food, researchers take the total amount of carbohydrates and subtract out the total amount of fiber. Available carbohydrates are what's left. After 50 grams of available carbohydrates have been consumed, blood sugar levels are measured over a period of 2 hours. The results are plotted on a graph and summarized in what is called glucose AUC, or "area under the curve." Glucose AUC shows the immediate impact of the food on our blood sugar. Measuring GI also requires a second step. In this second step, 50 grams of available carbohydrate are consumed, but this time the food involved is one of two reference foods: either white bread or pure sugar (pure glucose). Once again, blood sugar levels are measured over a period of 2 hours, and the glucose AUC is calculated. At this point, it is possible to compare the two results.

The impact of the first food on our blood sugar is compared to the impact of either white bread or glucose itself. When these two results are compared, the impact of the white bread or glucose is arbitrarily given a value of 100 to make the comparison easier. As an example, let's say that researchers are trying to establish a GI for green peas and they decide to compare the impact of green peas on blood sugar to the impact of white bread. And in this example, let's say that a person consumes a starchy vegetable like green peas, and the glucose AUC (area under the curve) is 48% as large the glucose AUC when white bread is consumed. In this case, the GI for green peas would be established at 48% of 100, or 48. (In fact, this is precisely the GI that we use for green peas at WHFoods.) WHFoods GI Rating System Most healthcare organizations use a "high," medium" and "low" rating system for GI. Using this system, foods get classified in the following way: Low GI 56-69 70 or greater We like this rating system.

It's also the one we used as the foundation for our own rating system at WHFoods. We kept each of these same categories (low, medium, and high). But we used the concept of avCHO (available carbohydrate) to establish a fourth category called "very low" as well as to rank some of our WHFoods as "low" even though they did not have a published GI value. Since over one-third of our WHFoods are vegetables that often contain very small amounts of avCHO, we thought that the addition of a "very low GI" category would be helpful for sorting out our vegetables in terms of their GI value. To qualify as "very low" our foods needed to have an avCHO of less than 5 grams. (We calculated avCHO by setting a standardized food serving size of 100 grams, recording the food's total carbohydrate content in grams, and subtracting out its total fiber in grams.) To qualify as "low" our foods needed to have an avCHO of 5 grams or more but less than 12 grams. Finally, we ended up classifying a few of our foods as low-GI even when they did not meet our avCHO criterion.

While researching the GI values for our foods, we came across research evidence for some particular foods that showed those foods to have a beneficial impact on blood sugar. When the preponderance of research studies for any food showed a beneficial impact on blood sugar, we classified that food as low-GI even if it did not meet our avCHO criterion. Here is a summary chart showing our WHFoods rating system criteria. WHFoods Glycemic Index Rating System Very Low GI Why Do Some GI Values Seem Surprising? One of the most interesting aspects of GI involves its relationship to the unique features of carbohydrates. Carbohydrates are definitely not the same with respect to their immediate impact on our blood sugar. For example, non-whole grain breads and pasta noodles both contain similar amounts of starch, and their starches are similarly composed of long chains of the simple sugar, glucose. But the 3-dimensional structure of bread allows more of the starch to be exposed to enzymes in our saliva and in our digestive tract. This greater exposure to enzymes allows more of the starch to be broken down into sugar and gives non-whole grain breads a generally higher GI value than non-whole grain pastas.

Similarly, two basic types of starch found in many foods - amylose and amylopectin - also influence their GI values, even if the foods have identical amounts of total starch. With respect to their GI, foods are also differently impacted by cooking. Many legumes, for example, have cell structures that are fairly resistant to disruption and help prevent breakdown of the starches inside their cells. For this reason, legumes tend to have lower-than-expected GI values, provided that they have not been overcooked. Before they have been ground into flour, whole grains also tend to have lower GI values due to the sturdiness of their cell structures. But after being ground into flour, their starches become more susceptible to breakdown and their GI value tends to increase. Of course, these descriptions are generalizations and can be different for specific legumes, specific grains, and specific flours. Still, they reflect a general pattern and principle: namely, that for a carbohydrate-containing food, the more its natural integrity becomes disrupted by processing or overcooking, the more its GI value is likely to be increased.

Minimal disruption of whole foods from their natural, unprocessed state is one of our key principles at WHFoods, and it is a principle 100% aligned with promotion of lower GI values. GI Ratings for the World's Healthiest Foods Food Group What is the Glycemic Index? - Ask Dr. Weil Ask Dr. Weil 2 min What Is the Glycemic Index? You often refer to the glycemic index. Can you please explain what it is and how to use it? – June 23, 2006 The glycemic index ranks carbohydrate foods on the basis of how they affect blood sugar (glucose). This is important for many people because eating a lot of foods that rank high on the glycemic index will produce spikes in blood sugar that can lead over time to loss of sensitivity to insulin, the hormone needed to allow blood sugar to enter cells for use as fuel. Insulin resistance is associated with obesity, high blood pressure, elevated blood fats, and an increased risk of type 2 diabetes . Carbs are not bad, despite the claims of the late Dr. Robert C. Atkins and other proponents of low-carb diets.

Rather, there are better and worse carbs, the difference having to do with the glycemic index. I recommend using the glycemic index as a guide to healthy carbohydrate consumption. In general, avoid frequent consumption and large servings of foods that rank high on this scale. There are several GI index lists on the Internet, but one of the most complete seems to be this one: To create a scale for comparison, pure glucose is ranked at 100. Foods that rank over 60 are considered high glycemic index carbs. In most indexes (there is some minor variation between lists) these include potatoes, refined white and wheat bread, raisins and other dried fruit, bananas, carrots and watermelon. Foods ranked “moderate” (between 45 and 60) include most types of pasta, bulgur, baked beans, yams, green peas, sweet potatoes, orange juice and blueberries. Low glycemic index foods (below 45) include beans, cruciferous vegetables, yogurt, grapefruit, apples and tomatoes. When using the glycemic index as a guide to food choices, you also have to consider “glycemic load,” a measure of how many grams of carbohydrate a normal serving contains.

For example, carrots rank high on the glycemic index, but the amount of carbohydrates you would actually consume in a normal serving is pretty low, only 6.2 grams. The low-carb folks tell people to avoid carrots (and beets), but this is not good advice. Unless you eat huge portions of them, those vegetables will not disturb your blood sugar very much, and they provide important phytonutrients. To calculate glycemic load, multiply the number (in grams) of the carbs you would consume in a serving by the food’s ranking on the glycemic index. Although glycemic index rankings are written as whole numbers, they actually are percentages, so if the GI of a food is 71, treat this as 71% when you do the math. Foods with a low glycemic load rank from one to 10; those with medium load range from 11-19 and those with high glycemic load rank at 20 or above. While the concept of glycemic load is helpful, doing calculations for everything you eat isn’t always practical.

Instead, to make better, simpler choices about carbohydrates, reduce consumption of processed and refined foods (such as snack foods, white bread, sweetened drinks, and sugary desserts). Eat more sweet potatoes and fewer white potatoes, less bread (unless it’s really chewy and grainy), more whole grains and fewer products made with flour, more temperate fruits (especially berries, cherries, apples, and pears) and fewer tropical ones, and more beans. Andrew Weil, M.D. The Glycemic Index Concept | Official web site of the Montignac Method Official web site of the Montignac Method The Glycemic Index Concept What are Glycemic Indexes (GI)? Glycemic indexes measure carbs’ from the perspective of their pure sugar/starch content in order to determine how they affect glycemia (blood sugar levels) after meals. What is glycemia? Glycemia refers to blood sugar levels, namely, the amount of sugar (glucose) in one’s blood. In the case of a person fasting, for example, blood sugar levels are approximately 1 g of glucose per liter of blood. Digestion transforms carbohydrates into glucose and by so doing raises blood sugar levels.

Blood sugar levels are critical to losing or gaining weight. Once we’ve digested our food, the blood sugar that is produced makes our bodies secrete insulin. Insulin is a hormone which, depending on the amount secreted, might or might not cause us to gain weight. Measuring Glycemic indexes For years people believed that equal portions of different carbohydrates generated the same blood sugar levels (glycemic responses). As of the mid 1970s, Crapo, a Californian researcher from Stanford University, discovered evidence to the fact that carbohydrates having the same pure sugar/starch content did not necessarily have the same impact on blood sugar levels. Crapo established that what has to be taken into consideration is a carbohydrate’s potential to raise blood sugar levels and how it rates in comparison to other carbs. Later, in 1981 and on the basis of the research carried out by Crapo since 1976, Jenkins, gave final shape to Glycemic Indexes (GI). Rather than focusing solely on how individual carbs increased blood sugar, Jenkins sought to improve the GI notion by using estimates on the hyperglycemia triangle area.

This area is given by the full blood-sugar curve of each carb tested, eaten alone and on an empty stomach. In order to design the GI scale, Jenkins arbitrarily assigned a value of 100 to glucose (much like we arbitrarily opted for the 0° centigrade measurement). The 100 figure also corresponds to when our bodies totally (100%) assimilate the sugar consumed. The index value of a pure carbohydrate is estimated by using standard portions and measuring them as follows: the area of the triangle of the carb being tested is divided by the area of the glucose triangle and the result is then multiplied by the 100 value. Area of the triangle of the tested carb Area of the glucose triangle x 100 Glycemic Indexes measure how a carb affects our blood sugar levels, namely, its potential for releasing a certain amount of sugar into our blood after each meal. We could say that GIs actually measure a carb’s biodisposition or intestinal absorption rate. For further information on intestinal absorption physiology If a carb’s sugar level index is high (as in the case of potatoes), the corresponding carb’s absorption rate will provoke high blood sugar levels.

Comparatively, carbs with low Glycemic Indexes (for example lentils) are digested at rates that generate low, or practically meaningless, glycemic response. For example, when measured by the 100 glucose value standard, the GI for fries is 95 whereas green lentils have a 25 GI. Nonetheless, it is important to note that carbohydrates’ GIs are not fixed. They can vary depending on a number of factors. A cereal’s GI, for instance, depends on the variety of cereal consumed and on its botanic origin. For fruit, GIs vary depending on how ripe the fruit is, on how it was processed, on its degree of hydration, and so on. For further information on the factors which modify Glycemic Indexes Why are Glycemic Indexes (GIs) important ? As mentioned before, GIs correspond to a carbohydrate’s potential to raise blood sugar levels. In other words, they tell us the degree to which certain carbs make our bodies secrete insulin. The more insulin our bodies secrete, the greater the chances of gaining weight.

Current nutritionists’ most serious misconception Despite warnings by GI experts such as Professor Gérard Slama, nutritionists continue to think of carbs in terms of their absorption speed. In fact, there a two types of nutritionists. The first type refers to traditionalists who refuse to evolve with recent scientific findings. Traditionalists either ignore or refuse to accept GIs and their significance. They continue to ignorantly speak of carbohydrates in terms of fast and slow sugars. There are many of these out there, particularly dietitians who work with sportsmen or, even worse, those who write press articles on the subject. These traditionalists contribute by means of their ignorance to perpetuating a misguided notion regarding the essentials of nutrition. The second type refers to people who, either out of their incomprehension or sheer ignorance, can be considered hypocrites, They have admitted the more avant-garde classification of carbs by Glycemic Indexes but have not wholly grasped the GI concept and continue to confusedly speak of GIs together with the outdated “fast and slow sugar” classification. For them, the GI notion is only relevant in measuring a carb’s absorption speed. From this perspective, the full carb content of food would always be transformed into sugar (glucose).

In this respect, the food with a low Glycemic Index would take longer to absorb and that, while the ensuing glycemia is lower, it would then tend to last longer. Seen from this angle, the sole purpose of Glycemic Indexes would be to measure the time span of glucose intestinal absorption processes. This approach is totally mistaken since it goes against the facts of how our bodies really work. In effect, the opposite is true. All of the tests carried out on GIs, particularly those done by Jenkins, prove that what low GIs indicate is that less quantities of glucose have been absorbed as opposed to the time span for the absorption of equal quantities of glucose. This misguided notion regarding GIs is, unfortunately, widespread among a scientific community that awkwardly preaches it any which way. In his book Brain Dieting (« La diététique du cerveau »), published by Odile Jacob in April 2003, Professor Jean-Marie Bourre, member of the French Medical Academy, states clearly that GIs measure the speed at which sugar is absorbed. This happens to be a totally false assumption.

In conclusion, we can only regret medical professionals’ failure to take into account Glycemic Indexes and their usefulness in regulating insulin secretion, a crucial element to gaining weight and diabetes. Glycemic Index and Glycemic Load Tweet This is the definitive table for both the glycemic index and the glycemic load. I am able to reproduce it here courtesy of the author, Professor Jennie Brand-Miller of the University of Sydney. It is based on a table in different format but no more foods published December 2008 in Diabetes Care. However, only the abstract is free online there. GI of 55 is low; GL of 10 is low. This table includes the glycemic index and glycemic load of more than 2,480 individual food items. Not all of them, however, are available in the United States. They represent a true international effort of testing around the world. The glycemic index (GI) is a numerical system of measuring how much of a rise in circulating blood sugar a carbohydrate triggers–the higher the number, the greater the blood sugar response. So a low GI food will cause a small rise, while a high GI food will trigger a dramatic spike.

A list of carbohydrates with their glycemic values is shown below. A GI of 70 or more is high, a GI of 56 to 69 inclusive is medium, and a GI of 55 or less is low. The glycemic load (GL) is a relatively new way to assess the impact of carbohydrate consumption that takes the glycemic index into account, but gives a fuller picture than does glycemic index alone. A GI value tells you only how rapidly a particular carbohydrate turns into sugar. It doesn't tell you how much of that carbohydrate is in a serving of a particular food. You need to know both things to understand a food's effect on blood sugar. That is where glycemic load comes in. The carbohydrate in watermelon, for example, has a high GI. But there isn't a lot of it, so watermelon's glycemic load is relatively low. A GL of 20 or more is high, a GL of 11 to 19 inclusive is medium, and a GL of 10 or less is low. Foods that have a low GL almost always have a low GI. Foods with an intermediate or high GL range from very low to very high GI.

Both GI and GL are listed here. The GI is of foods based on the glucose index–where glucose is set to equal 100. The other is the glycemic load, which is the glycemic index divided by 100 multiplied by its available carbohydrate content (i.e. carbohydrates minus fiber) in grams. (The "Serve size (g)" column is the serving size in grams for calculating the glycemic load; for simplicity of presentation I have left out an intermediate column that shows the available carbohydrates in the stated serving sizes.) Take, watermelon as an example of calculating glycemic load. Its glycemic index is pretty high, about 72. According to the calculations by the people at the University of Sydney's Human Nutrition Unit, in a serving of 120 grams it has 6 grams of available carbohydrate per serving, so its glycemic load is pretty low, 72/100*6=4.32, rounded to 4. Glycemic Index & Glycemic Load Rating Chart My previous glycemic index page, which this page supplants, was based on the 2002 table published in the American Journal of Clinical Nutrition.

That in turn supplanted my original glycemic lists page, which was based on the original 1995 publication of the American Journal of Clinical Nutrition. I know that some people would prefer the relative simplicity of a list of just the most common American foods. You can find such a list at . If you are looking for a relatively simple description of the glycemic index, please see my article titled "The Glycemic Index" at . Notice! You can print out this file. But before printing, be sure to check if the last column is fully visible. On my computer I needed to change the margins in Internet Explorer (with file, page setup) from 0.75 inches to 0.25 inches. You may need to make it even wider by changing the print setup orientation from the normal portrait to landscape. Then, please first check if you've got it by printing just one page of the table. This table may be freely utilized for personal use, but may not be copied to any other Web site or publication. Webmasters of other Web sites are, however, welcomed to link this Web page. Before asking about the glycemic index or glycemic load, please refer to my main Glycemic Index page .

Table of glycemic index and load values The average GI of 62 common foods derived from multiple studies by different laboratories High-carbohydrate foodsGI White wheat bread*75±2 Whole wheat/whole meal bread74±2 Speciality grain bread53±2 Unleavened wheat bread*70±5 Wheat roti62±3 Chapatti52±4 Corn tortilla46±4 White rice, boiled*73±4 Brown rice, boiled68±4 Barley28±2 Sweet corn52±5 Spaghetti, white49±2 Spaghetti, whole meal48±5 Rice noodles†53±7 Udon noodles55±7 Couscous†65±4 Breakfast Cereals Cornflakes81±6 Wheat flake biscuits69±2 Porridge, rolled oats55±2 Instant oat porridge79±3 Rice porridge/congee78±9 Millet porridge67±5 Muesli57±2 Fruit and fruit products Apple, raw†36±2 Orange, raw†43±3 Banana, raw†51±3 Pineapple, raw59±8 Mango, raw†5

1±5 Watermelon, raw76±4 Dates, raw42±4 Peaches, canned†43±5 Strawberry jam/jelly49±3 Apple juice41±2 Orange juice50±2 Vegetables Potato, boiled78±4 Potato, instant mashed87±3 Potato, french fries63±5 Carrots, boiled39±4 Sweet potato, boiled63±6 Pumpkin, boiled64±7 Plantain/green banana55±6 Taro, boiled53±2 Vegetable soup48±5 Dairy products and alternatives Milk, full fat39±3 Milk, skim37±4 Ice cream51±3 Yogurt, fruit41±2 Soy milk34±4 Rice milk86±7 Legumes Chickpeas28±9 Kidney beans24±4 Lentils32±5 Soya beans16±1 Snack products Chocolate40±3 Popcorn65±5 Potato crisps56±3 Soft drink/soda59±3 Rice crackers/crisps87±2 Sugars Fructose15±4 Sucrose65±4 Glucose103±3 Honey61±3

 Data are means.

*Low-GI varities were also identified. †Average of all available data. Glycemic index (GI) and glycemic load (GL) values determined in subjects with normal glucose tolerance: 2008 Food Number and Item How to Use the Glycemic Index How to Use the Glycemic Index In this Article The Bigger Picture: Glycemic Load and a Good Diet Some foods can make your blood sugar shoot up very fast. That's because carbohydrates like refined sugars and bread are easier for your body to change into glucose, the sugar your body uses for energy, than more slowly digested carbs like those in vegetables and whole grains. Eat a lot of those easy carbohydrates and you'll have a hard time controlling your blood sugar , even with insulin and diabetes medications . The glycemic index gives you a way to tell slower-acting "good carbs" from the faster "bad carbs." You can use it to fine-tune your carb-counting and help keep your blood sugar more steady. What Is the Glycemic Index? Glycemic index is a number. It gives you an idea about how fast your body converts the carbs in a food into glucose.

Two foods with the same amount of carbohydrates can have different glycemic index numbers. The smaller the number, the less impact the food has on your blood sugar. 55 or less = Low (good) 56- 69 = Medium 70 or higher = High (bad) Look for the glycemic index on the labels of packaged foods. You can also find glycemic index lists for common foods on the Internet. Harvard University has one with more than 100. Or ask your dietitian or nutrition counselor. Foods that are close to how they're found in nature tend to have a lower glycemic index than refined and processed foods. Glycemic Index Can Change That number is a starting point on paper. It could be different on your plate, depending on several things. Preparation. Fat, fiber, and acid (such as lemon juice or vinegar) lower the glycemic index. The longer you cook starches like pasta, the higher their glycemic index will be. Ripeness. The glycemic index of fruits like bananas goes up as they ripen. Other foods eaten at the same time.

Bring down the overall glycemic index of a meal by combining a high-glycemic index food with foods that have lower ones. Your age, how active you are, and how fast you digest food also affect how your body reacts to carbs. If you have a diabetes complication called gastroparesis , which delays your stomach from emptying, your body will absorb food much more slowly. Continued The Bigger Picture: Glycemic Load and a Good Diet The glycemic index shouldn't be the only thing you consider when making choices about what to eat. The fact a food has a low glycemic index doesn't mean it's super-healthy, or that you should eat a lot of it. Calories, vitamins , and minerals are still important. For example, potato chips have a lower glycemic index than oatmeal and about the same as green peas. But oatmeal and green peas have more nutrients . Portion sizes matter, too. The more of whatever kind of carbs you eat, the more they'll affect your blood sugar. That's what the glycemic load tells you. It's a number you may see along with the glycemic index in lists. Think of it as the glycemic index for a specific amount of that food.

Glycemic load helps you account for both the quantity and the quality of your carbs at the same time. Less than 10 is low; more than 20 is high. For a diet with a lower glycemic load, eat: More whole grains, nuts, legumes, fruits, vegetables without starch, and other foods with a low glycemic index Fewer foods with a high glycemic index, like potatoes, white rice, and white bread Less of sugary foods, including candy, cookies, cakes, and sweet drinks You can still eat foods with a high glycemic index. Just enjoy them in smaller portions, and offset them with nutritious, low-glycemic index foods when you do. WebMD Medical Reference Reviewed by Michael Dansinger, MD on September 26, 2014 Sources Glycemic Index and Diabetes: American Diabetes Association® En Español Glycemic Index and Diabetes The glycemic index, or GI, measures how a carbohydrate-containing food raises blood glucose. Foods are ranked based on how they compare to a reference food — either glucose or white bread. A food with a high GI raises blood glucose more than a food with a medium or low GI.

Meal planning with the GI involves choosing foods that have a low or medium GI. If eating a food with a high GI, you can combine it with low GI foods to help balance the meal. Examples of carbohydrate-containing foods with a low GI include dried beans and legumes (like kidney beans and lentils), all non-starchy vegetables, some starchy vegetables like sweet potatoes, most fruit, and many whole grain breads and cereals (like barley, whole wheat bread, rye bread, and all-bran cereal). Meats and fats don’t have a GI because they do not contain carbohydrate. Below are examples of foods based on their GI. Low GI Foods (55 or less) 100% stone-ground whole wheat or pumpernickel bread Oatmeal (rolled or steel-cut), oat bran, muesli Pasta, converted rice, barley, bulgar Sweet potato, corn, yam, lima/butter beans, peas, legumes and lentils Most fruits, non-starchy vegetables and carrots Medium GI (56-69) Pretzels, rice cakes, popcorn, saltine crackers melons and pineapple What Affects the GI of a Food? Fat and fiber tend to lower the GI of a food.

As a general rule, the more cooked or processed a food, the higher the GI; however, this is not always true. Below are a few specific examples of other factors that can affect the GI of a food: Ripeness and storage time — the more ripe a fruit or vegetable is, the higher the GI Processing — juice has a higher GI than whole fruit; mashed potato has a higher GI than a whole baked potato, stone ground whole wheat bread has a lower GI than whole wheat bread. Cooking method — how long a food is cooked (al dente pasta has a lower GI than soft-cooked pasta) Variety — converted long-grain white rice has a lower GI than brown rice but short-grain white rice has a higher GI than brown rice. Other Considerations The GI value represents the type of carbohydrate in a food but says nothing about the amount of carbohydrate typically eaten. Portion sizes are still relevant for managing blood glucose and for losing or maintaining weight. The GI of a food is different when eaten alone than it is when combined with other foods. When eating a high GI food, you can combine it with other low GI foods to balance out the effect on blood glucose levels. Many nutritious foods have a higher GI than foods with little nutritional value.

For example, oatmeal has a higher GI than chocolate. Use of the GI needs to be balanced with basic nutrition principles of variety for healthful foods and moderation of foods with few nutrients. GI or Carbohydrate Counting? There is no one diet or meal plan that works for everyone with diabetes. The important thing is to follow a meal plan that is tailored to personal preferences and lifestyle and helps achieve goals for blood glucose, cholesterol and triglycerides levels, blood pressure, and weight management. Research shows that both the amount and the type of carbohydrate in food affect blood glucose levels. Studies also show that the total amount of carbohydrate in food, in general, is a stronger predictor of blood glucose response than the GI. Based on the research, for most people with diabetes, the first tool for managing blood glucose is some type of carbohydrate counting . Because the type of carbohydrate can affect blood glucose, using the GI may be helpful in "fine-tuning" blood glucose management.

In other words, combined with carbohydrate counting, it may provide an additional benefit for achieving blood glucose goals for individuals who can and want to put extra effort into monitoring their food choices Last Reviewed: October 2, 2013 Last Edited: May 14, 2014 wcie-carbs, In this section

Question: The Glycaemic Index (GI) refers to?
Answer: Food