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Thread: slin and dextrose
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08-10-2002, 01:49 PM #1Associate Member
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slin and dextrose
i am just wondering wether i should take my dextrose right after my slin shot or after i have stocked up in simple sugars.so basically i am confused about this product if its simple or complex carb
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08-10-2002, 03:24 PM #2
You want a high Glycemic carb with a high insulin response and dextrose has those qualities. You can take it directly after your insulin shot. Honey is another example of something with those properties as well as Malto dextrin and table sugar. Don't judge by whether it is a complex or simple sugar that does not necessarily elicit the desired response. For example fructose is a poor choice to use after slin.
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08-10-2002, 03:51 PM #3Associate Member
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rickson the reason i ask is cuz i am told that your body breaks down simple carbs right away and for complex carbs it takes a while so if i went hypo or right after the slin shot it would make sense if i had simple carbs based on the theory above,if you dont think that stands please state that
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08-10-2002, 03:59 PM #4
Like I said all simple sugars do not rate as high on the GI chart or elicit a high insulin response as certain complex carbs like the example of fructose (simple sugar but bad for slin) or dextrose which is in reality not a simple sugar. Here you can read this for more info. Taken from an AF post.
International table of glycemic index and glycemic load values: 20021,2
Kaye Foster-Powell, Susanna HA Holt and Janette C Brand-Miller
1 From the Human Nutrition Unit, School of Molecular and Microbial Biosciences, University of Sydney, Australia.
ABSTRACT
Reliable tables of glycemic index (GI) compiled from the scientific literature are instrumental in improving the quality of
research examining the relation between GI, glycemic load, and health. The GI has proven to be a more useful nutritional
concept than is the chemical classification of carbohydrate (as simple or complex, as sugars or starches, or as available or
unavailable), permitting new insights into the relation between the physiologic effects of carbohydrate-rich foods and
health. Several prospective observational studies have shown that the chronic consumption of a diet with a high glycemic
load (GI x dietary carbohydrate content) is independently associated with an increased risk of developing type 2 diabetes,
cardiovascular disease, and certain cancers. This revised table contains almost 3 times the number of foods listed in the
original table (first published in this Journal in 1995) and contains nearly 1300 data entries derived from published and unpublished verified sources, representing > 750
different types of foods tested with the use of standard methods. The revised table also lists the glycemic load associated with the consumption of specified serving sizes
of different foods.
Key Words: Glycemic index o carbohydrates o diabetes o glycemic load
INTRODUCTION
Twenty years have passed since the first index of the relative glycemic effects of carbohydrate exchanges from 51 foods
was published by Jenkins et al (1) in this Journal. Per gram of carbohydrate, foods with a high glycemic index (GI)
produce a higher peak in postprandial blood glucose and a greater overall blood glucose response during the first 2 h after
consumption than do foods with a low GI. Despite controversial beginnings, the GI is now widely recognized as a reliable,
physiologically based classification of foods according to their postprandial glycemic effect.
In 1997 a committee of experts was brought together by the Food and Agriculture Organization (FAO) of the United
Nations and the World Health Organization (WHO) to review the available research evidence regarding the importance of carbohydrates in human nutrition and health
(2). The committee endorsed the use of the GI method for classifying carbohydrate-rich foods and recommended that the GI values of foods be used in conjunction with
information about food composition to guide food choices. To promote good health, the committee advocated the consumption of a high-carbohydrate diet (55% of
energy from carbohydrate), with the bulk of carbohydrate-containing foods being rich in nonstarch polysaccharides with a low GI. In Australia, official dietary guidelines
for healthy elderly people specifically recommend the consumption of low-GI cereal foods for good health (3), and a GI trademark certification program is in place to put
GI values on food labels as a means of helping consumers to select low-GI foods (4). Commercial GI testing of foods for the food industry is currently conducted by
many laboratories around the world, including our own. Many recent popular diet books contain extensive lists of the GI values of individual foods or advocate the
consumption of low-GI, carbohydrate-rich foods for weight control and good health (5).
Reliable tables of GI compiled from the scientific literature are instrumental in improving the quality of research examining the relation between the dietary glycemic
effect and health. The first edition of International Tables of Glycemic Index, published in this Journal in 1995 with 565 entries (6), has been cited as a reference in
many scientific papers. In particular, these tables provided the basis for the GI to be used a dietary epidemiologic tool, allowing novel comparisons of the effects of
different carbohydrates on disease risk, separate from the traditional classification of carbohydrates into starches and sugars. Several large-scale, observational studies
from Harvard University (Cambridge, MA) indicate that the long-term consumption of a diet with a high glycemic load (GL; GI x dietary carbohydrate content) is a
significant independent predictor of the risk of developing type 2 diabetes (7, 8) and cardiovascular disease (9). More recently, evidence has been accumulating that a
low-GI diet might also protect against the development of obesity (10, 11), colon cancer (12), and breast cancer (13). The EURODIAB (Europe and Diabetes) study,
involving >3000 subjects with type 1 diabetes in 31 clinics throughout Europe, showed that the GI rating of self-selected diets was independently related to blood
concentrations of glycated hemoglobin in men and women (14) and to waist circumference in men (15). In addition, higher blood HDL-cholesterol concentrations were
observed in patients consuming low-GI diets from the northern, eastern, and western European centers participating in the study (15). Indeed, several studies have shown
that the dietary GI is a good predictor of HDL concentrations in the healthy population, whereas the amount and type of fat are not (16-18). Thus, the GI has proven to
be a more useful nutritional concept than is the chemical classification of carbohydrate (as simple or complex, as sugars or starches, or as available or unavailable),
providing new insights into the relation between foods and health.
In parallel with these advances have been studies documenting the importance of postprandial glycemia per se for all-cause mortality and cardiovascular disease
mortality in healthy populations (19). For example, in the Hoorn study there was a significant association between the 8-y risk of cardiovascular death and 2-h postload
blood glucose concentrations in subjects with normal fasting glucose concentrations, even after adjustment for known risk factors (20). Multiple mechanisms are probably
involved. Recurring, excessive postprandial glycemia could decrease blood HDL-cholesterol concentrations, increase triglyceridemia, and also be directly toxic by
increasing protein glycation, generating oxidative stress, and causing transient hypercoagulation and impaired endothelial function (21, 22). If postprandial glycemia is
indeed important, then dietary treatment for the prevention or management of chronic diseases must consider both the amount and type of carbohydrate consumed.
An issue that is still being debated, particularly within the United States, is whether the GI has practical applications for the clinical treatment of diabetes and
cardiovascular disease. Three intervention studies in adults and children with type 1 diabetes showed that low-GI diets improve glycated hemoglobin concentrations
(23-25). In subjects with cardiovascular disease, low-GI diets were shown to be associated with improvements in insulin sensitivity and blood lipid concentrations (23,
26). In addition, evidence from both short-term and long-term studies in animals and humans indicates that low-GI foods may be useful for weight control. Laboratory
studies examining the short-term satiating effects of foods have shown that low-GI foods are relatively more satiating than are their high-GI counterparts (10). Compared
with low-GI meals, high-GI meals induce a greater rise and fall in blood glucose and a greater rise in blood insulin, leading to lower concentrations of the body's 2 main
fuels (blood glucose and fatty acids) in the immediate postabsorptive period. The reduced availability of metabolic fuels may act as a signal to stimulate eating (11). It is
also important to emphasize that many low-GI foods are relatively less refined than are their high-GI counterparts and are more difficult to consume. The lower energy
density and palatability of these foods are important determinants of their greater satiating capacity. In obese children, the ad libitum consumption of a low-GI diet has
been associated with greater reductions in body mass indexes (27). However, some experts have raised concerns about the difficulties of putting advice about GI values
into practice and of the potentially adverse effects on food choice and fat intake. For this reason, the American Diabetes Association does not recommend the use of GI
values for dietary counseling. However, the European Association for the Study of Diabetes (28), the Canadian Diabetes Association (29), and the Dietitians Association
of Australia (30) all recommend high-fiber, low-GI foods for individuals with diabetes as a means of improving postprandial glycemia and weight control.
REVISED INTERNATIONAL TABLE OF GI VALUES
For all clinical and research applications, reliable GI values are needed. Therefore, the purpose of this revised table is to
bring together all the relevant data published between 1981 and 2001 (Table 1). Unpublished figures from our
laboratory and those from others have also been included when the quality of the data could be verified on the basis of the
method used [ie, the method is in line with the principles advocated by the FAO/WHO Expert Consultation (2)]. In total,
the new table contains nearly 1300 separate entries, representing >750 different types of foods. This number of foods
represents an increase of almost 250% over the number provided when the international tables were first published in
1995. As in the original tables, the GI value for each food (with either glucose or white bread used as the reference food),
the type and number of subjects tested, the reference food and time period used, and the published source of the data are provided. For many foods there are 2
published values; therefore, the mean (±SEM) GIs were calculated and are listed underneath the data for the individual foods. Thus, the user can appreciate the variation
for any one food and, if possible, use the GI value for the food found in their country. It is hoped that the table will reduce unnecessary repetition in the testing of
individual foods and facilitate wider research and application of the GI. In some cases, the GI values for different varieties of the same type of food listed in the table
indicate the glycemic-lowering effects of different ingredients and food processing methods (eg, porridges made from rolled grains of different thicknesses and breads
with different proportions of whole grains). This information could assist food manufacturers to develop a greater range of low-GI processed foods.
View this table:
[in this window]
[THIS IS THE TALE THAT LOOKS PRETTY JUMBLED WHEN COPIED IN IT'S RAW FORM]]
TABLE 1 International table of glycemic index (GI) and glycemic load (GL) values: 20021
WHY DO GI VALUES FOR THE SAME TYPES OF FOODS SOMETIMES VARY?
Many people have raised concerns about the variation in published GI values for apparently similar foods. This variation
may reflect both methodologic factors and true differences in the physical and chemical characteristics of the foods. One
possibility is that 2 similar foods may have different ingredients or may have been processed with a different method,
resulting in significant differences in the rate of carbohydrate digestion and hence the GI value. Two different brands of
the same type of food, such as a plain cookie, may look and taste almost the same, but differences in the type of flour
used, in the moisture content, and in the cooking time can result in differences in the degree of starch gelatinization and
consequently the GI values. In addition, it must be remembered that the GI values listed in the table for commercially
available processed foods may change over time if food manufacturers make changes in the ingredients or processing methods used.
Another reason GI values for apparently similar foods vary is that different testing methods are used in different parts of the world. Differences in testing methods
include the use of different types of blood samples (capillary or venous), different experimental time periods, and different portions of foods (50 g of total rather than of
available carbohydrate). Recently, 7 experienced GI testing laboratories around the world participated in a study to determine the degree of variation in GI values when
the same centrally distributed foods were tested according to the laboratories' normal in-house testing procedures (31). The results showed that the 5 laboratories that
used finger-prick capillary blood samples to measure changes in postprandial glycemia obtained similar GI values for the same foods and less intersubject variation.
Although capillary and venous blood glucose values have been shown to be highly correlated, it appears that capillary blood samples may be preferable to venous blood
samples for reliable GI testing. After the consumption of food, glucose concentrations change to a greater degree in capillary blood samples than in venous blood
samples. Therefore, capillary blood may be a more relevant indicator of the physiologic consequences of high-GI foods.
Although it is clear that GI values are generally reproducible from place to place, there are some instances of wide variation for the same food. Rice, for example, shows
a large range of GI values, but this variation is due to inherent botanical differences in rice from country to country rather than to methodologic differences. Differences
in the amylose content could explain much of the variation in the GI values of rice (and other foods) because amylose is digested more slowly than is amylopectin starch
(32). GI values for rice cannot be reliably predicted on the basis of the size of the grain (short or long grain) or the type of cooking method. Rice is obviously one type of
food that needs to be tested brand by brand locally. Carrots are another example of a food with a wide variation in published GI values; the oldest study showed a GI of
92 ± 20 and the latest study a GI of 32 ± 5. However, the results of an examination of the SEs (20 compared with 5) and the number of subjects tested (5 compared with
8) suggest that the latest value for carrots is more reliable, although differences in nutrient content and preparation methods contributed somewhat to this variation.
An important reason GI values for similar foods sometimes vary between laboratories is because of the method used for determining the carbohydrate content of the test
foods. GI testing requires that portions of both the reference foods and test foods contain the same amount of available carbohydrate, typically 50 or 25 g. The available
or glycemic carbohydrate fraction in foods, which is available for absorption in the small intestine, is measured as the sum of starch and sugars and does not include
resistant starch. Most researchers rely on food-composition tables or food manufacturers' data, whereas others directly measure the starch and sugar contents of the
foods.
This difference in the accuracy of measurements of the carbohydrate content might explain some of the variation in reported GI values for fruit and potatoes and other
vegetables. Food labels may or may not include the dietary fiber content of the food in the total carbohydrate value, leading to confusion that can markedly affect GI
values, especially those for high-fiber foods. Consequently, researchers should obtain accurate laboratory measurements of the available carbohydrate content of foods
as an essential preliminary step in GI testing. The available carbohydrate portion of test and reference foods should not include resistant starch, but, in practice, this can
be difficult to ensure because resistant starch is difficult to measure. There is also difficulty in determining the degree of availability of novel carbohydrates, such as sugar
alcohols, which are incompletely absorbed at relatively high doses.
Measuring the rate at which carbohydrates in foods are digested in vitro has been suggested as a cheaper and less time-consuming method for predicting the GI values
of foods (33). However, only a few foods have been subjected to both in vitro and in vivo testing, and it is not yet known whether the in vitro method is a reliable
indication of the in vivo postprandial glycemic effects of all types of foods. It is possible that some factors that significantly affect glycemia in vivo, such as the rate of
gastric emptying, will not change the rate of carbohydrate digestion in vitro. For example, high osmolality and high acidity or soluble fiber slow down the gastric emptying
rate and reduce glycemia in vivo, but they may not alter the rate of carbohydrate digestion in vitro. It is difficult to mimic all of the human digestive processes in a test
tube. In fact, research results from our laboratory have shown that GI values measured in vivo can be significantly different for the same foods measured in vitro. Until
we know more about the validity of in vitro methods, it is not recommended that they be used in clinical or epidemiologic research applications or for food labeling
purposes because of the potential for large over- or underestimates of true GI values.
GUIDE TO THE USE OF THE REVISED TABLE
The GI values listed in the revised table represent high-quality data published in refereed journals or unpublished values
generated by Sydney University's Glycemic Index Research Service, often as a result of contract research by industry.
The foods have been described as unambiguously as possible by using descriptive data about the food given in the original
publication. In some cases, descriptive details were extensive, including the species or variety of plant food, the brand
name of the processed food, and the preparation and cooking methods. In other cases, the only description was a single
word (eg, potatoes or apple). If the cooking method and cooking time were stated in the original reference, the details are
given. The user should bear in mind that countries often have different names for the same food product or, alternatively,
the same name for different items. For example, Kellogg's Special K breakfast cereal is a very different product in North America (Kellogg Canada Inc) than in
Australia (Kellogg, Sydney, Australia), each of which has a different GI value. Similarly, food names may mean different things in different countries. For example,
biscuits, muffins, and scones have different meanings in North America and in Europe. The terms used in the revised table have been selected to be as internationally
relevant as possible.
Some research laboratories continue to use white bread as the reference food for measuring GI values, whereas others use glucose (dextrose); therefore, 2 GI values
are given for each food. The first value is the GI with glucose as the reference food (GI value for glucose = 100; GI value for white bread = 70), and the second value is
the GI for the same food with white bread as the reference food (GI value for white bread = 100; GI value for glucose = 143). When bread was the reference food used
in the original study, the GI value for the food was multiplied by 0.7 to obtain the GI value with glucose as the reference food. The table lists the reference food that was
originally used to measure the GI value of each food.
The foods in the table are separated into the following food groups: bakery products, beverages, breads, breakfast cereals and related products, breakfast cereal bars,
cereal grains, cookies, crackers, dairy products and alternatives, fruit and fruit products, infant formula and weaning foods, legumes and nuts, meal-replacement products,
mixed meals and convenience foods, nutritional-support products, pasta and noodles, snack foods and confectionery, sports bars, soups, sugars and sugar alcohols,
vegetables (including roots and tubers), and indigenous or traditional foods of different ethnic groups. Within each section, foods are arranged in alphabetical order by
common name. This classification of the foods was made on a practical rather than a scientific basis. There are no GI values given for meat, poultry, fish, avocados,
salad vegetables, cheese, or eggs because these foods contain little or no carbohydrate and it would be exceedingly difficult for people to consume a portion of the foods
containing 50 g or even 25 g of available carbohydrate. Even in large amounts, these foods when eaten alone are not likely to induce a significant rise in blood glucose.
GLYCEMIC LOAD
Both the quantity and quality (ie, nature or source) of carbohydrate influence the glycemic response. By definition, the GI
compares equal quantities of carbohydrate and provides a measure of carbohydrate quality but not quantity. In 1997 the
concept of GL was introduced by researchers at Harvard University to quantify the overall glycemic effect of a portion of
food (7-9). Thus, the GL of a typical serving of food is the product of the amount of available carbohydrate in that serving
and the GI of the food. The higher the GL, the greater the expected elevation in blood glucose and in the insulinogenic
effect of the food. The long-term consumption of a diet with a relatively high GL (adjusted for total energy) is associated
with an increased risk of type 2 diabetes and coronary heart disease (9).
In the revised table, 3 columns of data not given in the 1995 table are included: GL values, a nominal serving size for each food (weight in g or volume in mL), and the
carbohydrate content of each food (in g/serving). The GL values are included for most of the foods and were calculated by multiplying the amount of carbohydrate
contained in a specified serving size of the food by the GI value of that food (with the use of glucose as the reference food), which was then divided by 100. The nominal
serving sizes were chosen after consideration of typical serving sizes in different countries. The carbohydrate content was obtained from the reference paper or, when
not available, from appropriate food-composition tables (34-38). For indigenous foods, values were extrapolated from Western foods thought to be closest in composition
when the nutrient content was not available.
The purpose of including GL values in the revised table was to allow comparisons of the likely glycemic effect of realistic portion sizes of different foods. The data
should be used cautiously because they are not applicable to all situations. Portion sizes vary markedly from country to country and between people in the same country.
Researchers and health professionals should therefore calculate their own GL data by using appropriate serving sizes and carbohydrate-composition data. In the interest
of future editions of the table, we ask that reliable published and unpublished data be sent to us for consideration.
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08-10-2002, 04:34 PM #5Associate Member
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thanks for the good info
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