International Journal of Nutrition, Pharmacology, Neurological Diseases

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 10  |  Issue : 2  |  Page : 50--56

Glycemic Index of Commonly Consumed Snack Foods in Oman


Amanat Ali1, Mariam S Al-Hakmani2, Mostafa I Waly2, Musthafa Mohamed Essa3,  
1 School of Engineering, University of Guelph, Guelph, Ontario; Food Science and Nutrition Department, College of Agricultural and Marine Sciences, Sultan Qaboos University, Sultanate of Oman, Canada
2 Food Science and Nutrition Department, College of Agricultural and Marine Sciences, Sultan Qaboos University, Sultanate of Oman
3 Food Science and Nutrition Department, College of Agricultural and Marine Sciences, Sultan Qaboos University; Ageing and Dementia Research Group, Sultan Qaboos University, Oman, Sultanate of Oman

Correspondence Address:
Visiting Research Professor Amanat Ali
School of Engineering, University of Guelph, Albert A. Thornbrough Building, 50 Stone Road East, Guelph, Ontario N1G 2W1
Canada

Abstract

Objective: Study the effect of Omani coffee on the glycemic responses and glycemic index (GI) of commonly consumed snack foods in Oman. Methods: We evaluated 9 Omani snack foods including doughnut, croissant, cheese, chicken and fried egg sandwiches, sambosa (vegetables), fried and boiled vermicelli, white bread with red beans for their proximate composition and GI. The proximate composition was determined according to AOAC,[1] whereas GI was measured in 12 healthy human volunteers as described by Wolever et al.[2] Results: The proximate composition of snack foods differed significantly (P < 0.05). The moisture, crude protein and fat contents in foods ranged from 21.9 to 67.5%, 4.3 to 17% and 2.7 to 23.4 %, respectively. Almost similar blood glucose responses were observed when snack foods were given with either water or Omani coffee. Significant (P < 0.05) differences were observed in the GI of these foods, which ranged between medium and high GI category. The GI of these foods (with water) ranged between 60 and 75, whereas with Omani coffee the GI values ranged between 64 and 78. Higher GI values were observed for doughnut and cheese sandwich, whereas sambosa (vegetables) showed the lowest value. Overall, no significant (P < 005) differences were observed in the GI of snack foods when served either with water or with Omani coffee. Conclusion: The GI of Omani snack foods differed significantly. However, Omani coffee did not affect the GI of these snack foods.



How to cite this article:
Ali A, Al-Hakmani MS, Waly MI, Essa MM. Glycemic Index of Commonly Consumed Snack Foods in Oman.Int J Nutr Pharmacol Neurol Dis 2020;10:50-56


How to cite this URL:
Ali A, Al-Hakmani MS, Waly MI, Essa MM. Glycemic Index of Commonly Consumed Snack Foods in Oman. Int J Nutr Pharmacol Neurol Dis [serial online] 2020 [cited 2020 May 31 ];10:50-56
Available from: http://www.ijnpnd.com/text.asp?2020/10/2/50/282288


Full Text



 Introduction



Drastic changes have occurred in the lifestyle and food consumption patterns of Omani people over the past years. Although there has been a decline in infectious diseases in Oman,[3] the rate of diet and lifestyle-related non-communicable diseases (NCDs) such as obesity, diabetes, hypertension, metabolic syndrome, heart diseases and cancer has increased.[4],[5],[6] The higher prevalence of NCDs has been associated with sedentary lifestyle and unhealthy dietary habits.[7],[8] The results of our latest study suggest that high daily caloric intake increases the risk of non-Hodgkin’s lymphoma (NHL), whereas increased intake of vegetables reduces the risk.[9] Type 2 diabetes mellitus and glucose intolerance are highly prevalent among the Middle Eastern populations.[10] The prevalence of diabetes in Oman has increased during the last decade and it is expected to rise further in 2030.[11],[12] By adopting simple preventative approaches such as dietary and lifestyle modifications, one can reduce the risk of chronic disease.[6],[13],[14],[15]

Glycemic index (GI) of foods is a valuable method to classify the starchy foods based on their glycemic responses during the postprandial period.[16],[17] The use of this concept in daily meal planning may help the diabetic patients to manage their hyperglycemic and hyperinsulinemic responses and lower the risk of obesity, diabetes, heart diseases and cancer.[16],[18],[19],[20] The data from various epidemiological studies and controlled randomized clinical trials show that the low GI diets may not only improve the glycemic control in diabetic subjects[19],[21],[22] but may also have beneficial effects in normal healthy subjects in lowering the risk of non-communicable chronic diseases such as obesity, diabetes mellitus, coronary heart diseases, and cancers.[20],[23] The GI of foods should therefore be considered as important criteria in the dietary management and prevention of obesity, diabetes, coronary heart diseases and cancers.[18],[20],[24],[25],[26]

In the globally changing food environment, snacking has become very common and Oman is no exception to it. Snack foods have been variably defined in different countries and cultures.[27],[28] In general, the terms “snack” is used to describe the foods eaten in-between 3 regular daily meals, whereas snacking refers to frequently eating small portions of foods throughout the day without any set schedule.[27] Depending upon the type, nature and origin of snack food, it can be either energy-dense or nutrient-dense. The people eat snack foods for many different reasons, to fulfill their hunger, for pleasure, to enjoy taste, flavour, texture and other characteristics of foods, to release stress and pass time when bored or to satisfy their psychological behaviours. The snacks containing high amounts of sugar and fat, however, contribute to significant amounts of calories without adding much nutrients.[29] The quality of snack foods and the frequency of their consumption, however, determines their usefulness in meeting the daily nutrient and energy needs. Snacking didn’t show a consistent relationship with body weight in adults or children.[30],[31] Snacking has been reported to contribute to increased energy intake among the US overweight and obese adolescents as compared to normal weight.[32] The choice of consumer is therefore crucial in determining their nutritional effects in terms of meeting nutrient needs or increasing the risk of weight gain and obesity.[33] The small portion size and low energy-dense snacks were found to be positively associated with higher diet quality and healthy eating index-2015 scores among US preschoolers.[34] Healthier snack foods can have favourable effect on satiety, glucose homoeostasis and may reduce the risk of obesity.[30],[35] As the consumer’s demand for high-quality snack foods is increasing, it is important to have a database on the GI of snack foods, so that consumers can make a nutritionally healthy choice in selecting them to prepare their daily meal plans. A few studies have reported the GI of snack foods consumed in various parts of the world.[36],[37],[38],[39],[40] Most of the snack foods in Oman are generally consumed with traditional Omani coffee. It has been shown that ingestion of caffeinated coffee may affect the insulin sensitivity and lead to impaired glucose homeostasis,[41] whereas data from other studies indicate that consuming caffeinated coffee didn’t affect the insulin sensitivity or mediators of insulin resistance, insulinemic responses and GI of foods.[42],[43],[44] In our previous studies, we determined the GI of some local Omani foods.[45],[46],[47] This information is however, limited and doesn’t grasp all the Omani foods, which are consumed in different ways and their GI needs to be evaluated. The present study was therefore conducted to determine the effect of Omani coffee on the glycemic responses and GI of nine commonly consumed snack foods in Oman.

 Materials and Methods



Collection and preparation of food samples

Nine different types of snack foods (doughnut, croissant, cheese, chicken and fried egg sandwiches, vegetables sambosa, fried and boiled vermicelli and white bread with red beans) commonly consumed in Oman, were evaluated in this study. Some of the ready-made foods such as doughnuts, croissant, chicken sandwiches, and vegetable sambosa were purchased from the local market, while the other foods were prepared according to the standard local recipes as described by the Ministry of Health Nutrition Bulletin for Food Recipes.[48] All these foods are commonly consumed in Oman and a few of them sometime may also serve as the main meal. For example, the sweet vermicelli (local names “Swayweih” or “Ballaleet”) is mainly cooked with sugar and is prepared both as fried and in boiled form. The cooked red beans make another important common dish that is prepared in almost every home in Oman and is mostly consumed with different types of breads.

The proximate chemical composition (moisture, ash, crude fibre, crude protein and total fat) was determined according to the methods of AOAC.[1] The values for nitrogen free extract (NFE) expressed as total carbohydrates were calculated by difference (100 minus other components i.e., moisture, crude protein, total fat, ash and crude fibre). The values are expressed as g per 100g of food on as such basis. Total dietary fibre was determined according to the AOAC official enzymatic-gravimetric-MES-TRIS buffer method 991.43.[1] The gross energy value of food (kcal/100g) was determined based on the amount of total carbohydrates, crude protein and fat present by multiplying with the factors 4, 4 and 9, respectively. The available carbohydrates were determined by subtracting the amount of dietary fiber from total carbohydrates.[49]

Preparation of Omani coffee and determination of caffeine

Omani coffee was prepared according to the standard recipes for Omani foods by boiling 30g of medium roasted ground Arabian coffee (obtained from the local market) in 800 mL of water for 20 minutes and then 5g of grounded cardamom was added and continued boiling for another 5 minutes.[48] The Omani coffee was decanted to remove the sediments and the supernatant was gushed into a traditional coffee pot (known as “Dellah”) and 2 tsp. of rose water was added to it. The caffeine content in the Omani coffee was determined according to the method of Van Atta.[50] The average concentration of caffeine in Omani coffee was found to be 1.73 mg/ml. The volunteers were given 130 ml of Omani coffee that contained on the average 225 mg of caffeine.

Determination of Glycemic Index of snack foods

Twelve normal healthy non-smoker university students, free from any apparent symptoms of diseases, were recruited as volunteers for measuring the GI.[49] An oral glucose tolerance test was conducted to rule out diabetes.[51] The average age, weight, height and BMI of the volunteers were 25.3±2.2 years, 59.5±15.6 kg, 1.6±0.1 m and 22.9±3.5 kg/m2 respectively. They were briefed about the study and a signed written consent was obtained. The study was approved by the Medical Research and Ethics Committee of College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.

To measure the GI portions of test food and standard reference food (glucose) containing 50g of available carbohydrates were given to volunteers in a random order on separate occasions after an overnight fast of ≥10 hours. A standard drink of either pure water (250 ml) or 130 mL of Omani coffee was given with each test food on separate occasions. The volunteers were asked to comfortably eat the test foods within 5-6 minutes. The GI test foods were determined in one series of tests either with water or with Omani coffee. The test for standard reference food (glucose) was repeated thrice (in the beginning, middle and end) and the average values were used to calculate the GI of foods. The blood glucose level was measured at 0 (fasting), 15, 30, 45, 60, 90 and 120 minutes after the intake of foods, using SureStep Brand Professional Blood Glucose Meter that employs a dry reagent technology based on the glucose oxidase method.[52] The calculations, for the incremental area under the curve (IAUC), were carried out according to the method described by Wolever and colleagues.[2] The GI values were calculated as:

Glycemic Index = (IAUC test food / IAUC standard reference food) × 100

Statistical analysis of the data

All the data was entered into Microsoft Excel Software and a common dataset was created and transferred to SPSS v.19. Descriptive analysis and one-way analysis of variance of data was carried out to calculate the average means and standard error of mean (SEM). The means were compared using least significant difference (LSD) test as described by Snedecor and Cochran.[53] Data Desk Software program was used for repeated measurement analysis. In a repeated measurement analysis, the same subject was observed at different levels of one factor called "repeat" in the multivariate form (within-subjects design) but at the same level of at least one grouping or treatment factor (between-subjects design). Overall, the results deemed statistically significant at P < 0.05.

 Results and Discussion



Proximate chemical composition of commonly consumed snack foods in Oman

The proximate composition of commonly consumed Omani snack foods is shown in [Table 1]. The snack foods varied significantly (P < 0.05) in their chemical composition. The moisture content varied between 21.9 to 67.5%, whereas the crude protein and total fat ranged from 4.3 to 17 and 2.7 to 23.4 %, respectively. The cooked red beans showed the highest crude fiber (6.96 ± 0.7 g/100g) and dietary fiber contents (7.6 ± 0.1 g/100g). The lowest ash content (0.1%) was found in boiled vermicelli. The highest energy value (403 ± 8 kcal/100g) was observed in croissant followed by doughnut (376 ± 7 kcal/100g). The variability in chemical composition of these snack foods may be attributed to their ingredient composition and preparation methods. Our results are in line with the findings reported in earlier studies, which provide some information regarding the chemical composition of some traditional dishes from Oman as well as from other Arab Gulf countries but do not cover all the foods consumed in this region.[38],[46],[47],[54],[55] The data from the present study adds new first-hand information to nutritional database on chemical composition and GI of commonly consumed foods in Oman.{Table 1}

Glycemic Index of commonly consumed snack foods served with water

The average fasting blood glucose values (0 minutes) and blood glucose responses after the ingestion of standard food (glucose) and different test foods when served with water at 15, 30, 45, 60, 90 and 120 minutes are shown in [Figure 1]. The average fasting blood glucose value of volunteers (97 mg/dL) was within the normal range. The volunteers did not show any impaired fasting blood glucose (IFG) responses as indicated by the glucose response curve of the standard reference food (glucose). Different snack foods produced variable glycemic responses [Figure 1]. The highest blood glucose response after 15 minutes of ingestion of foods was observed with fried vermicelli, followed by boiled vermicelli, white bread with red beans, cheeses sandwich, fried egg sandwich and others. This trend however changed subsequently at 30, 45, 60, 90 and 120 minutes after ingestion of food. After 120 minutes all foods showed almost similar blood glucose values as at the baseline. The GI of these foods ranged between 60 and 75 [Table 2]. Significant differences (P < 0.05) were observed in the GI of these foods. The highest average GI value of 75 was observed for doughnut, while the lowest average GI value of 60 was noted for sambosa (vegetables). No significant (P < 0.05) differences were however observed in the GI values for doughnut, cheese sandwich, fried egg sandwich and fried vermicelli. Significant (P < 0.05) differences were also detected between the GI values of fried and boiled vermicelli. However, no significant (P < 0.05) differences were noticed in the GI values for croissant, chicken sandwich and boiled vermicelli. Similarly, the GI values of sambosa (vegetables) and white bread with red beans, did not differ significantly (P > 0.05).{Figure 1}{Table 2}

Glycemic Index of commonly consumed snack foods served with Omani coffee

During this phase, the test foods were given with 130 ml of Omani coffee, which on the average contained 225 mg of caffeine. The average fasting blood glucose levels (at 0 minutes) and the blood glucose responses after the ingestion of different test foods with 130 ml of Omani coffee at 15, 30, 45, 60, 90 and 120 minutes are shown in [Figure 2]. The standard reference food (glucose) was given with water. Different snack foods produced variable glycemic responses when served with Omani coffee. However, these responses remained within the normal ranges and were almost similar to those when these foods were consumed with water [Figure 2]. The highest blood glucose response, after 15 minutes of ingestion of snack foods with Omani coffee, was observed for fried vermicelli, followed by cheese sandwich, boiled vermicelli, white bread with red beans, fried egg sandwich and others. This trend, however, changed subsequently at 30, 45, 60, 90 and 120 minutes after food ingestion. The blood glucose levels after 120 minutes of food ingestion, were almost similar to the baseline levels (fasting blood glucose). Significant differences (P < 0.05) were observed in the GI values of these foods, which ranged between 64 and 78 [Table 3]. The highest average GI value of 75 was observed for cheese sandwich, whereas the lowest GI value of 57 was for sambosa (vegetables). The GI values for doughnut, cheese sandwich, fried egg sandwich and chicken sandwich did not differ (P < 0.05). Similarly, no significant (P < 0.05) differences were observed among the GI values of croissant, fried and boiled vermicelli, and white bread with red beans.{Figure 2}{Table 3}

The comparative data on the glycemic index of different snack foods

The comparative data on the GI of different snack foods, when served with either water or Omani coffee is given in [Table 4]. Overall, no significant (P < 005) differences were observed in the GI of foods when served with water or with Omani coffee. The data on the glycemic responses of these foods in individual subjects was analyzed by repeated measurement analysis. Significant differences were observed in individual glycemic responses for the same food as well as for GI of individual foods. Ingestion of caffeinated coffee has been shown to affect the insulin sensitivity and may lead to impaired glucose homeostasis.[41],[56] However, the data from several other studies indicate that consuming caffeinated coffee didn’t affect the insulin sensitivity as well as the mediators of insulin resistance, insulinemic responses and GI of foods.[42],[44] The results of our study did not show any difference in the GI of commonly consumed Omani snack foods, when served with either water or Omani coffee. This may be due to various factors in particular, the variability in the amount of caffeine consumption by the subjects in each study or the method of coffee preparation and the presence of bioactive components in coffee.[57],[58] The amount of Omani coffee given to our study subjects was 130 ml that contained 225 mg of caffeine. Our findings are similar to those reported by Gavrieli et al.,[59] who noticed that coffee consumption at a level of 250 mg of caffeine has no major effect on glucose metabolism in healthy adults and is therefore not associated with any adverse effects. Data from previous studies indicate that habitual coffee intake is related to lower risk of type 2 diabetes mellitus.[44],[57],[58],[60] The lower GI values observed for sambosa (vegetables) and white bread with red beans may be attributed to their high fibre contents. In addition to this sambosa (vegetables) is fried in oil and this type of cooking may result in slower release and absorption of glucose from these foods.[47] Pulses and legumes are rich sources of fiber and contain galactomannans, which are more viscous than the fiber in wheat and rice.[61] The viscosity of dietary fiber is positively correlated with a reduction in postprandial plasma glucose levels, as high fiber foods can enhance the postprandial endothelial function.[62] In Omani community the red kidney beans are mostly eaten in combination with bread or rice, which may help to reduce the GI of mixed meals.Boiled and fried vermicelli showed almost similar GI, when served with Omani coffee. However, when served with water, the GI of boiled and fried vermicelli differed significantly. Vermicelli, prepared in either boiled or fried form, is a typical Omani dish that is likewise consumed in other Gulf countries and is locally called as “Ballaleet”.[54] Foods, with similar ingredient composition but processed by different methods, can have significantly different rates of digestion and absorption and hence may result in different GI values. There is no standardized definition of how much volume of coffee constitutes a cup, as it can range from 25 to 330 ml. It is thus important when considering how many "cups" of coffee are consumed per day, which may have some protective effects against diabetes. In Oman, the coffee is offered in small cups without handle called “Fingaan”, which are filled less than half of the cup containing about 15-20 ml of coffee. The size of a coffee cup is an important consideration in measuring the consumption of coffee. The quantities of coffee taken with the snack foods are usually small. The method of coffee preparation as well as the addition of other substances to enhance its flavour can largely affect the components of brewed beverage and may present a confounding factor, if these variables are not considered.[57],[63] Our results on the GI of commonly consumed Omani snack foods are similar to those reported from various other parts of the world.[36],[37],[38],[39],[40]{Table 4}

 Conclusions



Based on the results of this study fried vermicelli, boiled vermicelli and white bread with red beans can be grouped into medium GI category of foods, whereas doughnuts, cheese sandwich, chicken sandwich and fried egg sandwich are grouped into high GI category. The results of this study report for the first time, the GI of commonly consumed snack foods in Oman and add valuable information not only to the local nutrient database but also to global database on GI values of foods. Further research is required to determine the GI of other mixed meals and Omani dishes to supplement the nutrient database of local Omani foods. It will help to develop strategies for inclusion of these foods in daily meal planning to control the glycemic spikes in normal and diabetic patients for the prevention and management of diabetes.

Dedication

In the memory of our late graduate student Mrs. Mariam S. Al-Hakmani, who left us at very young age.

Acknowledgement

We express our sincere thanks to study volunteers for their cooperation and help. Thanks, are also due to Ms. Buthaina S Al-Bulushi for her technical assistance and Dr. Michael Claereboudt for his help in statistical analysis of data. We greatly acknowledge the financial assistance provided by Sultan Qaboos University under an internal research grant (IG/AGR/FOOD/10/01).

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.[64]

References

1AOAC and AoOA Chemists. Official Methods of Analysis. 18th ed. 2005, Arlington, VA: Association of Official Analytical Chemists.
2Wolever TM et al. The glycemic index: methodology and clinical implications. The American Journal of Clinical Nutrition 1991;54:846-54.
3Ganguly SS et al. Epidemiological transition of some diseases in Oman: a situational analysis. EMHJ − Eastern Mediterranean Health Journal 2009;15:209-18.
4Al-Riyami AA, Afifi MM, Morsi MM. Diabetes in Oman. Saudi Med J 2005;26:1015-17.
5Al-Lawati J et al. Trends in the risk for cardiovascular disease among adults with diabetes in Oman. Sultan Qaboos University Medical Journal 2015;15:e39-e45.
6Al-Mawali A. Non-communicable diseases: shining a light on cardiovascular disease, Oman’s biggest killer. Oman Medical Journal 2015;30:227-8.
7Mabry RM, Morsi M, Owen N. descriptive epidemiology of sitting time in Omani men and women: a known risk factor for non-communicable diseases. Oman Medical Journal 2017;32:233-9.
8Zayed K et al. Obesity, eating habits and sedentary behaviour of Omani young adolescents: a cross-sectional study. EC Nutrition 2017;7:3-10.
9Ali A et al. Dietary and lifestyle factors and risk of non-Hodgkin’s lymphoma in Oman. Asian Pac J Cancer Prev 2013;14:841-8.
10Majeed A et al. Diabetes in the Middle-East and North Africa: an update. Diabetes Research and Clinical Practice 2014;103:218-22.
11Al-Shookri A et al. Type 2 diabetes in the sultanate of Oman. Malays J Nutr 2011;17:129-41.
12Al-Shafaee M et al. Quality of diabetes care in primary health centres in North Al-Batinah of Oman. The Open Cardiovascular Medicine Journal 2014;8:48-54.
13Psaltopoulou T, Ilias I, Alevizaki M. The role of diet and lifestyle in primary, secondary, and tertiary diabetes prevention: a review of meta-analyses. Rev Diabet Stud 2010;7:26-35.
14Schulze MB et al. Food based dietary patterns and chronic disease prevention. BMJ 2018;361:k2396.
15Mahmoud MAA et al. Dietary and lifestyle determinants of the lifetime cardiovascular risk during early adulthood. Progress in Nutrition 2019;21.
16Jenkins D et al. Glycemic index of foods: a physiological basis for carbohydrate exchange. The American Journal of Clinical Nutrition 1981;34:362-6.
17Wolever TMS et al. Glycemic index and insulinemic index of foods: an interlaboratory study using the ISO 2010 method. Nutrients 2019;11.
18Brand-Miller J et al. Dietary glycemic index: health implications. Journal of the American College of Nutrition 2009;28:446S-9S.
19Livesey G et al. Dietary glycemic index and load and the risk of type 2 diabetes: a systematic review and updated meta-analyses of prospective cohort studies. Nutrients 2019;11.
20Turati F et al. Glycemic index, glycemic load and cancer risk: an updated meta-analysis. Nutrients 2019;11.
21Yari Z et al. New insight into diabetes management: from glycemic index to dietary insulin index. Curr Diabetes Rev 2019 doi: 10.2174/1573399815666190614122626.
22Riccardi G, Rivellese AA, Giacco R. Role of glycemic index and glycemic load in the healthy state, in prediabetes, and in diabetes. Am J Clin Nutr 2008;87:269s-274s.
23Henry CJ et al. A low glycaemic index diet incorporating isomaltulose is associated with lower glycaemic response and variability, and promotes fat oxidation in asians. Nutrients 2017;9.
24Augustin LS et al. Glycemic index, glycemic load and glycemic response: an International Scientific Consensus Summit from the International Carbohydrate Quality Consortium (ICQC). Nutr Metab Cardiovasc Dis 2015;25:795-815.
25Cai X et al. Dietary carbohydrate intake, glycaemic index, glycaemic load and digestive system cancers: an updated dose–response meta-analysis. British Journal of Nutrition 2019;121:1081-96.
26Ojo O et al. The effect of dietary glycaemic index on glycaemia in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials. Nutrients 2018;10:pii:E373.
27Potter M, Vlassopoulos A, Lehmann U. Snacking recommendations worldwide: a scoping review. Adv Nutr 2018;9:86-98.
28Hess JM, Jonnalagadda SS, Slavin JL. What is a snack, why do we snack, and how can we choose better snacks? A review of the definitions of snacking, motivations to snack, contributions to dietary intake, and recommendations for improvement. Adv Nutr 2016;7:466-75.
29Shriver LH et al. Contribution of snacks to dietary intakes of young children in the United States. Matern Child Nutr 2018;14.
30Njike VY et al. Snack food, satiety, and weight. Adv Nutr 2016;7:866-78.
31Larson NI et al. Adolescent snacking behaviors are associated with dietary intake and weight status. J Nutr 2016;146:1348-55.
32Tripicchio GL et al. Associations between snacking and weight status among adolescents 12-19 years in the United States. Nutrients 2019;11.
33Bellisle F. Meals and snacking, diet quality and energy balance. Physiol Behav 2014;134:38-43.
34Kachurak A et al. Daily snacking occasions, snack size, and snack energy density as predictors of diet quality among US children aged 2 to 5 years. Nutrients 2019;11.
35Yan MR et al. Effects of a healthier snack on snacking habits and glycated Hb (HbA1c): a 6-week intervention study. Br J Nutr 2016;116:2169-74.
36Krishnamoorthy G, Pande AS, Moulick ND. Traditional Indian snacks modified to attain low glycaemic index and confirmed suitable to be consumed without hyperglycaemic effect in type 2 diabetics. J Indian Med Assoc 2011;109:222-9.
37Kaur B et al. The impact of a low glycaemic index (GI) diet on simultaneous measurements of blood glucose and fat oxidation: a whole body calorimetric study. J Clin Transl Endocrinol 2016;4:45-52.
38Al Dhaheri AS et al. Glycaemic index and glycaemic load values of commonly consumed foods in the United Arab Emirates. British Journal of Nutrition 2017;117:1110-7.
39Papakonstantinou E et al. Short-term effects of a low glycemic index carob-containing snack on energy intake, satiety, and glycemic response in normal-weight, healthy adults: Results from two randomized trials. Nutrition 2017;42:12-9.
40Tan WSK et al. The glycaemic index and insulinaemic index of commercially available breakfast and snack foods in an Asian population. Br J Nutr 2018;119:1151-6.
41Moisey LL et al. Caffeinated coffee consumption impairs blood glucose homeostasis in response to high and low glycemic index meals in healthy men. Am J Clin Nutr 2008;87:1254-61.
42Aldughpassi A, Wolever TM. Effect of coffee and tea on the glycaemic index of foods: no effect on mean but reduced variability. Br J Nutr 2009;101:1282-5.
43Hatonen KA et al. Coffee does not modify postprandial glycaemic and insulinaemic responses induced by carbohydrates. Eur J Nutr 2012;51:801-6.
44Alperet DJ et al. The effect of coffee consumption on insulin sensitivity and other biological risk factors for type 2 diabetes: a randomized placebo-controlled trial. Am J Clin Nutr 2019;111:448-58.
45Ali A, Al-Kindi YS, Al-Said F. Chemical composition and glycemic index of three varieties of Omani dates. Int J Food Sci Nutr 2009;60:51-62.
46Ali A et al. Glycemic index and chemical composition of traditional Omani breads. International Journal of Food Properties 2010;13:198-208.
47Ali A et al. Chemical composition, fatty acids content and glycemic index of two different types of Omani halwa. Pakistan Journal of Nutrition 2013;12:753-60.
48MOH, M.o.H. Chemical composition and recipes of common Omani foods. 2006, Ministry of Health: Muscat, Oman.
49Brouns F et al. Glycaemic index methodology. Nutrition Research Reviews 2008;18:145-71.
50Van Atta RE. Ultraviolet spectrophotometric determination of caffeine in cola drinks: an organic analytical experiment. Journal of Chemical Education 1979;56:666.
51ADA and A.D. Association, diagnosis and classification of diabetes mellitus. Diabetes Care 2006;29:S43-48.
52Marks V, Dawson A. Rapid stick method for determining blood-glucose concentration. British Medical Journal 1965;1:293-4.
53Snedicor GW, Cochran WG. Statistical methods. 1989, Iowa, USA: Iowa State University Press.
54Musaiger AO, Ahmed MA, Rao MV. Chemical composition of some traditional dishes of Oman. Food Chemistry 1998;61:17-22.
55Al Nagdy SA, Abd-El Ghani SA, Abdel-Rahman MO. Chemical assessment of some traditional Qatari dishes. Food Chemistry 1994;49:261-4.
56Reis CEG, Dorea JG, da Costa THM. Effects of coffee consumption on glucose metabolism: a systematic review of clinical trials. J Tradit Complement Med 2019;9:184-91.
57Rakvaag E, Dragsted LO. Acute effects of light and dark roasted coffee on glucose tolerance: a randomized, controlled crossover trial in healthy volunteers. Eur J Nutr 2016;55:2221-30.
58Shokouh P et al. Effects of unfiltered coffee and bioactive coffee compounds on the development of metabolic syndrome components in a high-fat-/high-fructose-fed rat model. Nutrients 2018;10.
59Gavrieli A et al. Caffeinated coffee does not acutely affect energy intake, appetite, or inflammation but prevents serum cortisol concentrations from falling in healthy men. J Nutr 2011;141:703-7.
60Lim Y et al. The effect of coffee consumption on the prevalence of diabetes mellitus: the 2012-2016 Korea National Health and Nutrition Examination Survey. Nutrients 2019;11.
61Margier M et al. Nutritional composition and bioactive content of legumes: characterization of pulses frequently consumed in France and effect of the cooking method. Nutrients 2018;10.
62Gaesser GA et al. Effects of glycemic index and cereal fiber on postprandial endothelial function, glycemia, and insulinemia in healthy adults. Nutrients 2019;11.
63Cherniack EP, Buslach N, Lee HF. The potential effects of caffeinated beverages on insulin sensitivity. Journal of the American College of Nutrition 2018;37:161-7.
64Scazzina F et al. Glycemic index and glycemic load of commercial Italian foods. Nutr Metab Cardiovasc Dis 2016;26:419-29.