Reliable Glycemic Index Values of Variety of Food - Article Example

Abstract The objectives of the experiment is to establish the effects of ingesting different types of food which has different carbohydrates content on blood glucose levels in standard healthy blood; to learn the value of glycaemic index in choosing food that are rich in carbohydrates especially in situations where one wants to control weight or suffering from disease such as diabetes mellitus; to find out the concentration of carbohydrates and glycaemic in different types of food; to obtain skills in safe sampling and handling of human blood. The method used was a student volunteer who consumed 50g of available carbohydrate contained in a specified carbohydrate rich food. And 6 different types of food containing carbohydrates were consumed by male and female students after an interval of 15 hours. The glucose contained was analyzed before 15, 30, 45, 60, and 90 minutes after the food was taken by use of capillary blood samples (Ya-jun 2010). The glycaemic value of every tested food was calculated by expressing the incremental area under the blood glucose response curve value for the food tested as a % of every subject’s average IAUC rate for the glucose. The results show that the BGI varies in the body at different times and the BGL from different ages varies likewise to the amount from different food substance. The blood glucose level of different food provides vital information for the researchers, doctors, sports men and people who want to reduce or increase their weights. Introduction When GI was introduce by Jenkins et al, it was first defined as the incremental area under the blood glucose response curve when a certain amount of food that contains 50g of present carbohydrates nutrients was expressed as % of that after equal measure of carbohydrates from a reference meal taken by similar subject. The GL was recently introduced in order to reflect the overall glucose response and it is calculated as the glycemic index value of the meal multiplied by the available amount of carbohydrates in the normal portion amount, divided by hundred. The glycemic load and glycemic index have been shown by different research work to be related to certain chronicle diseases such as metabolic syndrome, diabetes, and certain types of cancer diseases (Thomas 2006). If meals that have low GL and GI are taken, it will contribute to the reduction in the body mass when there is an overweight, adult suffering from obesity, and hearth diseases. The role of glycemic index in determining the glycemic effect of the food that has different content of protein, carbohydrates, and fats has drawn interest for the exploration by the researchers. The response of the glycemic elicited by food is expressed as a % of the glycemic response elicited when 50g present carbohydrate from the glycemic index of certain food is referred as the RGR (relative glycemic response). The equation used to determine the RGR of food from its glycemic index and the amount of carbohydrates it contains is = 1.5 x GI x (1 – e–0.018 x GAvCHO) + 13. Relative glycemic response explains 90 percent of the changes in the mean glucose responses produced by food that are mixed in normal subjects. (GL) glycemic load is defined as glycemic index time’s grams of carbohydrates was a concept that was introduced as a measure of GI effect of diets and its accounts for carbohydrates source and amounts together(Ya-jun 2010). Two recent scientific studies that tested large composite of food arrive at a conclusion that RGR, GI, and GL of certain type of meal does not predict the glycemic response produced by mixed food. Therefore part of the experiment conducted was to a certain whether the GI and carbohydrate contents of certain specific meals was the determinants of the glycemic effect of the regular food that varied in fat, energy, protein, and carbohydrate contents and in glycemic index. The relationship between mean glycemic effect of the test food and their calculated glycemic index and relative glycemic response values was also measured (Thomas 2006). Materials and methods 192 students both male and female volunteered to take part in the study. And six different types of food were used. All the students were on good conditions, no reported case of diabetic and no reported case of pregnancy in women or breast feeding among female students. All the students involved were supposed to refrain from taking vigorous alcohol and taking part in vigorous physical activities twenty four hours before the experiment was carried out. The students were not supposed to consume large amount of food as usual and have balanced diet on the pervious day. After ten to fourteen hours of overnight fast, the students reported in the labs between eight and ten am. The students were tested for about 15 minutes and the baseline finger-brick capillary samples blood of about 0.7 ml was collected from the fingers into heparinized tubes, the blood plasma was removed and kept at a temperature of -20 °C before the glucose and insulin content was analyzed. After the test, the students consume a test food containing 50g of carbohydrates and additional blood samples was taken again at an interval of 15, 30, 45, 60, and 90 minutes after the students have started consuming the food and the same test was carried out. A clean water of 250ml was provided to be taken together with the foods to be tested and all the meals was to be consumed within ten minutes. The food substance used include apple, chocolate, dates, ryvita, mars bar, and jelly beans. The three types of food have different energies. The glycaemic index was calculated as follows. Where n is the number of carbohydrate-containing foods in the meal GAvCHOa is the grams of carbohydrates available in the ath food GIa = GI of the ath food The glycaemic load is calculated using the following formula Where GI is the test meal GI and GAvCHO is the grams of available carbohydrates in the test food While RGR was calculated as The Incremental areas under the glucose curves (AUC) were calculated while the area under the fasting concentration was neglected. An AUC value from every center was subjected to recurring measures analysis of variance and the important difference between individual means was calculated by the use of tukeys test to adjust for multiple comparisons. To find out the relative effect of the available glycemic index, carbohydrates, fats, and protein concentration of the tested food on glucose and insulin responses, simple and step wise multiple linear regression analysis of the nourishment variables was performed on mean AUC, with the effects of the middle being entered into the model by using dummy numerical variables. Results All the students completed the experiment successfully. The determined BLG level after every 15 minutes for all students having taken similar or different food were shown in the table was shown in the table. The BGL of every type of food vary with time, it starts from a lower figure rises with time and then drop again after 60 minutes. The blood glucose from each sample after 15 minutes was then measured and their values were plotted in the graph. The test food was compared with the reference food response. The GI index was then calculated through taking the average GI of the students. Graphs Showing the Effect of Glucose (reference food), High GI Food, and Low GI Food on Blood Glucose Level on six different types of food. There is an acute rise in BGL when a student takes glucose. For about 30 minutes the BLG are at the maximum for this food substance. After the maximum, the BLG then drop down quickly to where it was before. Also food containing high GI gives rise to a fast increase in blood glucose level. But BLG level do no become as high as reference food, maximum BLG are reached after 45 minutes and it will start dropping, this level of increase and decrease vary between different foods. On the the effect of low GI food on BGL; Maximum BGL occurs after 45 minutes of meal consumption. BGL rise and fall gradually but with these they take a longer time and its peak is much lower Discussion and conclusion The availability of reliable glycemic index values of variety of food is of great significance to the researchers and common people. The class has determined the GI and BGL of six types of food and has shown that glycemic index is a reproducible measure of day long postprandial glycemia. Recently food substances that are being sold have their GI branded on the packing because of close relationship between the GI and the body health. Though glycemic is a classification of blood glucose raising potential of carbohydrate foods, different factors may influence the GI of foods such as food form, cooking methods, starch structure and others. If fat and protein are added to the carbohydrate foods, it reduces the postprandial glycemic response which comes up through different mechanism like delaying gastric emptying. On the other hand many research studies have found out that the amount of protein or fats in the frequently consumed foods does not affect the glycaemic responses. The current research has found out that no relation existed between the amounts of fats or proteins in food and their glycaemic index value. Even though there is a recommended standard protocol of calculating the GI, there is still some methodological factors considered to affect the accuracy of the GI while determining. One research suggested that the characteristics and composition of the food may influence the blood glucose tolerance the following morning. The latest study suggest that advising the people involved to avoid consuming certain types of food is good and may be more cost-effective. That is why according to the class study, the students was advised to take a balance diet and refrain from drinking alcohol and engaging in active physical activities a night before the test was carried out. Works cited Ya-jun chen et al. 2010. Glycaemic index and glycaemic load of selected Chinese traditional foods. Retrieved on 31/ 08/ 2010 from http://docs.google.com/viewer?a=v&q=cache:2nfqy3vy8nYJ:www.wjgnet.com/1007-9327/16/1512.pdf+experiment+on+Glyceamic+Index&hl=en&gl=ke&pid=bl&srcid=ADGEESidKmxi554CF60VnfWTsqrK0C1bk3F64NiLuyAbmN1cyVCZqkqUwOKJBg92kJxPnPyi83TaBz1pSJBhmfARl3pXNqzbrN2NXfr9dq0W1OvNiI_d23dQ6ijT9MtBCg8F_NCeiauY&sig=AHIEtbSGLByNVG7VjvocQBvoFNsNM8hkiQ. Thomas MS wolver et al. 2006. American Journal of Clinical Nutrition. Retrieved on 31/08/2010 from http://www.ajcn.org/cgi/content/full/83/6/1306. Garry Egger. 2001. The Experts' Weight Loss Guide: For doctors, health professionals. Allen & Unwin. London Lucy Beale, & Joan Clark. 2005. The Complete Idiot's Guide to Glycemic Index Weight Loss. Alpha Books. New York. Thomas M. S. Wolever. 2006. The glycaemic index: a physiological classification of dietary carbohydrate. Cabi Series. Harvard. Read More