OPEN ACCESS Pakistan Journal of Nutrition
The Effect of Coffee Consumption on Blood Glucose: A Review
Amal Hassan Alshawi
Department of Nutrition and Food Science, Princess Nourah Bint Abdulrahman University, Riyadh, Kingdom of Saudi Arabia
This review describes the impact of drinking coffee on glycemic profile parameters (glycemic index [GI], glycemic load [GL], glucose
tolerance and insulin sensitivity) and diabetes mellitus. Coffee is very popular in Arab communities including Saudi Arabia. Clinical research
has revealed the negative effect of caffeine including a reduction in insulin sensitivity that impairs glucose tolerance. Epidemiological
studies also show that drinking coffee has positive effects on both glucose tolerance and sensitivity to insulin, which might assist in
reducing the risk of type 2 diabetes especially over long periods of consumption. More studies are thus needed to gain a deeper
understanding of how coffee drinking is linked to type 2 diabetes.
Key words: Caffeine, diabetes mellitus, insulin sensitivity, glucose tolerance, chlorogenic acid, coffee consumption
Citation: Amal Hassan Alshawi, 2020. The effect of coffee consumption on blood glucose: A review. Pak. J. Nutr., 19: 420-429.
Corresponding Author: Amal Hassan Alshawi, Department of Nutrition and Food Science, Princess Nourah Bint Abdulrahman University,
Riyadh, Kingdom of Saudi Arabia
Copyright: © 2020 Amal Hassan Alshawi. This is an open access article distributed under the terms of the creative commons attribution License, which
permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.
Competing Interest: The author has declared that no competing interest exists.
Data Availability: All relevant data are within the paper and its supporting information files.
Pak. J. Nutr., 19 (9): 420-429, 2020
The word coffee derives from the Arabic word
, leading to the Latin botanical genus
. Of the
coffee which is actually drunk, 99% comes from just two of the
103 kinds of coffee that have been discovered:
(Robusta). Coffee growing
occurs in sixty tropical and subtropical nations. Around 60% of
the coffee produced globally is grown on the American
continent. Here, Arabica coffee with its low caffeine content
and bitterness predominates1. Golden coffee, which comprises
around 95% of all coffee exports, is produced through minimal
processing of the green coffee beans2. Coffee is very common
in many countries with the highest per capita consumption
being in Europe where the average consumption is between
2.4 and 12 kg per person per year3.
Coffee contains caffeine, which is a bioactive compound.
It stimulates the central nervous system and positively affects
long-term memory. Drinking coffee has historically been
associated with negative health effects, more recent studies
show that it may be beneficial1. Consuming approximately
#400 mg of caffeine daily (3-4 cups) of brewed coffee or
having five cups of tea or five caffeinated soft drinks regard as
moderate seems to affect health in a neutral to positive way.
Adolescents can safely consume 100-175 mg of caffeine per
day while the safe level for children aged 6-12 is 45-85 mg4. In
Saudi Arabia, the term Arabic coffee is usually applied to a
green coffee bean extract that is very popular. Spices such as
saffron and cardamom are added to the roasted green coffee
beans to enhance the color and taste of the resulting coffee
product. In Saudi Arabia, as in other Arab Gulf countries, coffee
is usually drunk with snacks especially soft dates.
The efficiency of consuming brewed coffee on human
health has been the focus of many studies5. This review aims
to evaluate how drinking coffee affects blood glucose and the
implications for insulin sensitivity and glucose tolerance as
well as its impact on diabetes.
Search strategy: Databases were searched for a randomized
controlled trial that examined the effects of coffee
consumption on blood glucose in healthy humans. The
following keywords in the title/abstract were used: caffeine,
diabetes mellitus, insulin sensitivity, glucose tolerance,
chlorogenic acid and coffee consumption. The reference lists
from selected reports were reviewed for further relevant
studies. Studies that investigated the effect of different coffee
drinks are included because coffee consumption occurs more
frequently than pure caffeine intake in daily life.
A review of the literature was conducted utilizing
databases such as PubMed, Google Scholar, LWW Health
Library and Science Direct. Furthermore, studies cited in the
selected articles were verified. Studies on association of
caffeine, coffee consumption and diabetes were included.
General properties of coffee: When coffee beans are ripe,
they can be processed by the wet method or by drying in the
sun for 3-9 days (the dry method). A temperature of 200EC is
required for the necessary transformation to take place during
roasting. When this occurs, the coffee beans become dry,
brittle and brown; they increase in size and develop their
characteristic aroma and flavor. Regardless of whether coffee
is prepared on an industrial scale or brewed at home, hydrous
extraction of the dissolved roast and ground coffee is
The coffee quality is determined by the chemical
composition of the roasted beans, which is also affected by
drying, storing, roasting and grinding after the harvest. The
coffee bean quality relies on color, shape and size of the bean,
the crop year, the processing methods, the roast potential and
the processing method as well as the flavour7. Roasting is vital
because the chemical compounds that are generated by the
changes that happen during the roasting process are what
gives coffee its characteristic flavour8.
Recent research has demonstrated that coffee and its
by-products are rich in antioxidants. They contain trigonelline
and chlorogenic acids as well as caffeine, which are all
bioactive compounds9. These compounds have a positive
effect on health and this means that coffee is potentially a
functional food product2.
The coffee plant has a secondary metabolite which is
caffeine, (1, 3, 7-trimethylxanthine)-a purine alkaloid. The
caffeine content in the green coffee beans varies. If calculated
by dry weight, it represents up to 2.3% of Robusta beans
and up to 1.3% of Arabica beans. Coffee beans also contain
fairly large amounts of chlorogenic acids, which are widely
distributed secondary metabolites in plants with 5-O-
caffeoylquinic acid being the most common6. After
investigating the effects of various methods of brewing on the
polyphenol, methylxanthine and antioxidant capacities of 13
different brews of coffee, Baeza
.10 concluded that their
antioxidant capacities complied with the total phenol and
chlorogenic acid derivate contents. Wachamo
suggested that the high phenolic content of green coffee
probably accounted for its association with the reduced threat
of diseases of oxidative etiology. The impact of drinking coffee
on various health consequences was reviewed by Bordenave
.12 who concluded that it benefitted carbohydrate and
lipid metabolism as well as the cardiovascular system.
Pak. J. Nutr., 19 (9): 420-429, 2020
The blood glucose response to foods: Currently, the focus in
the glycemic response (GR) to foods is of considerable interest
because it is thought to have a relationship with chronic
diseases including obesity, diabetes and cardiovascular
disease13. GR to a food or meal for a person is specified by the
amount and quality of the carbohydrates14 and this can be
ascertained by the GI, GL, or glycemic impact15. The concept of
the GI was first coined in 1981 by Augustin
.13 in their
research with patients who had type 2 diabetes mellitus. The
carbohydrate content of specific foods is evaluated by the GI
by measuring their glycemic effects after they have been
ingested16,17. The GI could be demonstrated as the incremental
area beneath the curve of the blood glucose response to a
50 g portion of available carbohydrate of a tested sample. It is
expressed as a percentage of the same person reaction after
eating an identical carbohydrate portion from standard food.
The variability and/or value of the GI results can be influenced
by a number of methodological factors; however, variation can
be minimized and reproducible findings obtained by careful
use of appropriate methods18.
The Food and Agriculture Organization of the United
Nations (FAO)/World Health Organization (WHO) outlines the
most appropriate method for calculating the GI19. The FAO, in
its consultation report on dietary carbohydrates in human
nutrition, suggests using GI values as well as other data on
food composition19. Low GI foods like legumes and low-fat
animal products are recommended as part of many
weight-loss diets20. All published data on the GI values of
600 particular foods was compiled and listed in a single table
To assist in the creation of a local food exchange list for
diabetics, Al-Mssallem21 identified the GI value of popular
Saudi foods. Fohl, gareesh, korsan, kelija eneazaa and kelija
malkee are five common Saudi foods with high carbohydrate
content and were evaluated for their GI values (45, 89, 61, 58
and 51%, respectively). Alkaabi
.22 assessed the GI values
of five popular types of dates in both diabetic and healthy
individuals. Their findings demonstrated a low GI value for all
five types of dates and the authors concluded that the dates
would not cause a significant rise in the concentration of
postprandial glucose if eaten by diabetics. Farhat
investigated the GI values of Lebanese mixed meals and
desserts and found that they ranged from intermediate
(50-70%) to low (#50%). A study on the GI values of breakfast
cereals in the diet of United Kingdom (UK) citizens showed
that these ranged from high ($70%) to low (#55%); most had
a moderate GI of between 60 and 65%24.
To measure GL, the entire amount of ingested
carbohydrates (in grams) is multiplied by the GI value of each
food and then divided by 10025. Wh en t he e ffe ct of GI/ GL o n
appetite and GR were identified, there were no significant
differences in appetitive rating, plasma glucose, insulin
response, or food consumption26. The GR is modulated by
several aspects of the meal including the nutrient
composition, the duration, volume/weight, energy density,
rheology and palatability27,28.
The GR is a food's capacity to raise blood sugar29. The way
that food has been processed or cooked affects GR30. Because
dietary fats slow the absorption of glucose, they may delay the
blood glucose and insulin responses31,32. Bataineh investigated
the glycemic and insulinemic indices of some popular Arabic
sweets when ingested by healthy individuals and found that
substituting olive oil for ghee in maa'moul, ghuraybah and
hareesah lowered GRs without a significant effect on the
insulinemic responses33. The blood glucose response of foods
containing differing amounts of carbohydrates can be
compared directly with the glycemic glucose equivalent
(GGE); the glucose quantity in grams would result in a GR
equal to a particular weight of a food34,35. Observing the
glucose continuously might be used to record the GR with
levels of interstitial glucose reported every 5 to 10 minutes
continuously for 3-7 days for a comprehensive observation of
the GR of a single meal or food36.
Due to lack and/or resistance of insulin, type 2 diabetes
mellitus is linked with the target tissues impaired insulin
response. Although increased insulin secretion overcomes
insulin resistance at first, this compensation ultimately fails
and results in progressively raised blood glucose levels. Before
people develop type 2 diabetes, they go across a stage of
impaired glucose tolerance (IGT) and increased plasma
glucose levels during fasting; thus, this stage is an
intermediate dysglycemia state between diabetes and
normal glucose tolerance37. The American Diabetes
Association proposed a new diagnostic criterion in 199738
whereby diabetes screening was carried out by testing plasma
glucose levels during fasting39. The importance of measuring
insulin sensitivity is frequently highlighted due to its
important role in diabetes, cardiovascular and hypertension
disease40; tools to measure insulin sensitivity and resistance is
a key goal of many studies41-43. Song
.44 studied the
relationship between insulin resistance and dietary behavior
among healthy people in Korea: They found that a pattern
based on beans and whole grains was linked with a lower
prevalence of insulin resistance.
The effect of coffee consumption on the glycemic profile: If
people are to make informed choices about drinking coffee
and public health initiatives are to be prioritized appropriately,
then it is important to know the benefits and adverse effects
Pak. J. Nutr., 19 (9): 420-429, 2020
on health45. The relationship between coffee components like
antioxidant phenolic compounds, c af fe i ne , m i cronutrients and
fiber suggests beneficial effects3. According to Van Dam
coffee contains a number of substances that may impact
The Hoorn45 study was a cross-sectional and prospective
study that was population-based and involved Dutch male
and female adults with a range of age 50-74 years. Initially, an
oral glucose tolerance test (OGTT) was conducted and a
follow-up was performed during an average period of six years
and four months. Some variables such as cigarette smoking,
alcohol intake, body mass index (BMI), physical activity and
dietary factors were adjusted. The results showed that habitual
coffee-drinking can lower the threat of IGT and impact post-
load rather than fasting glucose metabolism45. A link between
habitual coffee-drinking and the incidence of increased
plasma glucose levels during fasting, IGT and type 2 diabetes
Caffeine is one of the substances other than
macronutrients that can affect insulin sensitivity and blood
glucose concentrations in individuals with diabetes46. Despite
research carried out on short terms with people in good
health that continue to indicate that ingesting caffeine
cause acute transient insulin resistance and IGT47,48, these
conclusions appear to be contradicted by epidemiological
studies46. For an individual with existing diabetes, blood
glucose concentrations may be affected by caffeine in various
ways. Glucose transportation from blood to the muscles may
be hindered by caffeine as it acts as an adenosine receptor
antagonist to inhibit the uptake of glucose into muscle cells
even when insulin is present49. Moreover, elevated blood
glucose concentrations due to caffeine intake could be a
consequence of high epinephrine (adrenaline), which in turn
induces insulin resistance50,51. Other studies have also shown
how caffeine might impact glucose metabolism. Luiz
found that caffeine intake led to a significant increase
in blood glucose concentrations. Robinson
.54 c on fi r me d t h at i ng es t in g ca f fe i ne i nc r ea s ed g lu co s e
concentration and loaded when compared to a placebo. Both
studies noted that caffeine caused a reduction in the insulin
sensitivity index compared to placebo.
Several studies have addressed the short-term and
long-term effects of coffee or caffeine consumption on
glucose tolerance55; they concluded that coffee consumption
and/or caffeine impaired glucose tolerance in the short-
term56,57. IGT is a state of hyperglycemia where resistance to
insulin sensitivity happens in peripheral tissues as a response
to glucose58. Insulin resistance and glucose tolerance can be
impaired by short-term administration of coffee, which
blocks the impact of the adenosine AI receptor that regulates
the uptake of glucose in skeletal muscles59. However, the
findings from some epidemiological studies demonstrate
that long-term and habitual coffee drinking might support
standard glucose tolerance and enhance insulin sensitivity60-63.
Thus, coffee may suppress insulin sensitivity in the short-term
but drinking coffee regularly can stimulate glucose tolerance
and insulin sensitivity64-66. In other words, ingesting caffeine
habitually changes the negative impact of caffeine on glucose
tolerance and insulin sensitivity to a positive one55.
Consuming coffee and caffeine were linked to lower
serum levels of leptin and plasminogen activator
inhibitor-167. In elderly individuals, low coffee consumption
for short periods predicts impairment of normal glucose
tolerance68 while also lowering glucose tolerance in healthy
men69. However, other studies report different results:
.70 demonstrated that subjects showed a marked
reduction in blood glucose concentration after drinking coffee
although insulin levels were not affected. Shengxi
noted that just the intake of coffee polyphenols enhances
peripheral endothelial function after glucose loading among
adults in good health. Thom72 reported that instant coffee
enriched with chlorogenic acid lowered glucose absorption by
6.9% versus a control.
A lowered insulin sensitivity after short-term ingestion of
coffee72-74 may be due to the caffeine-induced antagonism
of adenosine receptors accompanied by a rise in levels of
epinephrine75. For individuals with type 2 diabetes mellitus,
the impact of drinking black espresso coffee does not seem to
be mediated by alterations in insulin sensitivity76. For the study
of insulin secretion and sensitivity, long-term trials on the
impact of caffeine and some components of coffee could be
more related. A cross-sectional study of 936 male senior
citizens without type 2 diabetes revealed that drinking coffee
was linked to higher insulin sensitivity but not a reduced
secretion of insulin61; however, a cross-sectional study of 2112
healthy women found a potential decrease of insulin secretion
as the result of consuming coffee. It is possible that this
decrease could be relevant to a constituent in coffee other
Recent research reported no alteration in postprandial
glycemic response to Lebanese mankoucheh when
accompanied by Turkish coffee77. Post-exercise insulin
concentrations and blood glucose were significantly changed
by caffeine and extract from green beans of coffee versus
Type 2 diabetes and consuming coffee: The global increase
in diabetes seems to be due to population ageing and
urbanization wi th ass oc iat ed alt er ati on s in ph ysi ca l a cti vi ty
Pak. J. Nutr., 19 (9): 420-429, 2020
and diet79. Specific criteria and diagnostic tests were used to
identify people who are pre-diabetic and thus at risk of
developing diabetes as well as those who have diabetes80.
Diabetes is classified into type 1, type 2, gestational and
secondary diabetes80. The vast majority of diabetics (90-95%)
have type 2, which used to be called non-insulin-dependent
or adult-onset diabetes81. Preventing type 2 diabetes is now a
significant public health issue. Type 2 diabetes can largely be
avoided by a healthy life style and a sound dietary pattern82.
Treatment of diabetes is focused on normalizing metabolism
with an emphasis on blood glucose and lipids especially
low-density lipoprotein (LDL), cholesterol and blood pressure
to prevent complications that are diabetes-related81.
Coffee contains a significant amount of caffeine and
chlorogenic acid and is a complex mix of chemicals. Over the
last few decades, studies have identified the benefit or
harm to health from drinking coffee83. Coffee may impact
postprandial hyperglycemic excursion, although there
have been conflicting results. Drinking coffee raises energy
expenditure and thermogenesis to induce insulin sensitivity84.
Coffee can produce an acute impairment of glucose tolerance
or insulin resistance in healthy, non-diabetic adults and has
been consistently demonstrated by a minimum of 17
short-term studies. We concluded that this effect contributes
to the progression of type 2 diabetes in susceptible people85.
Conversely, long-term coffee intake is possibly linked
with a lowered threat of type 2 diabetes86,87. Alkaabi
suggested that eating dates with coffee was common among
Arabs and that this might affect hyperglycemic excursion after
meals. They studied the effect of coffee on the GI tract of type
2 diabetic and healthy subjects when eating a common variety
of dates. They found that coffee did not adversely impact
capillary glucose levels after the consumption of dates either
in diabetic or healthy subjects at least in the short-term
Information about the daily coffee consumption of a sample
of 1141 American Indian males and females with a range of
age 45-74 years was collected in a prospective cohort study.
The sample was within the normal average of glucose
tolerance at the baseline examination and was monitored with
a mean of 7.6 years. The findings indicated that subjects who
consumed more than 11 cups of coffee per day had a 67%
lower threat of developing diabetes through the follow-up
period compared to non-coffee consumers89. Another
prospective study followed 910 adults aged $50 years with a
mean of 8 years after their coffee consumption had been
assessed. These findings indicated that both former and
current coffee consumers had a reduced risk of diabetes
incident versus people who never ingest coffee. The subjects
with impaired baseline glucose who were former and current
coffee consumers also had a lower risk of diabetes. This
research strikingly demonstrates how caffeinated drinking
coffee can protect against the incidence of diabetes63.
Furthermore, according to Hamer
.90, more than
fourteen cohort studies have revealed a reverse association
between drinking coffee beverages and the threat of
type 2 diabetes. Hamer
.90 investigated the prospective
association between consuming coffee and tea beverages
and the threat of type 2 diabetes mellitus. The study was
conducted for 11.7 years of follow-up with a sample of
4055 males and 1768 females from the Whitehall cohort in the
UK; they concluded that drinking a moderate amount of
coffee and tea (more than 3 cups a day) was not prospectively
linked with the incidence of type 2 diabetes90. A cross-
sectional study of 954 non-diabetic adults who drink
caffeinated coffee on a regular basis based on a food
frequency questionnaire found a positive link to insulin
sensitivity that was inversely related to 2 h post-load glucose
levels91. Dutch male and female adults were followed for
a mean duration of 6.4 years in another prospective
cross-sectional study. They found that drinking coffee favored
post-load rather than fasting glucose45. Research conducted
with 2434 Finnish men and women reported that drinking
coffee had a significant and inverse link with both fasting
glucose and insulin and also with the response to a 2 h
glucose tolerance test55,92.
A review of these epidemiologic studies showed that
drinking coffee can significantly decrease the threat of type 2
.55 found a number of mechanisms
that might be involved. Ryanodine receptors are activated by
caffeine and this improves the insulin secretion of $-cells of
the pancreatic islets. Glucose metabolism and homeostasis are
regulated by chlorogenic acid and magnesium55. Chu
reported numerous compounds in coffee that may produce a
matrix effect by working together and providing bioactivities
that lower the threat of evolving type 2 diabetes. Finally,
coffee consumption is linked with the threat of diabetes
mellitus, the occurrence of stroke, heart failure and some
cancers in an inverse dose-dependent fashion; however, there
may be harmful effects related to high anxiety, insomnia and
acute myocardial infarction97,98. However, until the association
between the threat of type 2 diabetes and long-term coffee
consumption is more thoroughly understood, it would be
premature to suggest coffee intake consumption as a way of
preventing type 2 diabetes mellitus55,99,100.
Pak. J. Nutr., 19 (9): 420-429, 2020
CONCLUSIONS AND RECOMMENDATIONS
Generally, the literature on short-term clinical trials that
addressed the link between consuming coffee and type 2
diabetes mellitus shows that caffeine decreases insulin
sensitivity and negatively affects glucose tolerance.
Nevertheless, several prospective cohort studies in various
countries have demonstrated that drinking coffee is linked
with a significant decrease in the threat of developing type 2
diabetes mellitus. More studies are required to clearly
understand how the main components of coffee affect
glucose metabolism. Moreover, epidemiologic research needs
to be carried out in Arab populations and specifically in the
Saudi community to accurately identify how drinking coffee
affects blood glucose and other aspects of health. Effective
strategies in clinical research and related epidemiological
studies are needed to clarify the effect of coffee consumption
for people with type-diabetes especially in the local contest.
The use of coffee drinks could be a practical, effective and
environmentally friendly method to enhance insulin
1. Mejia, E.G.d. and M.V. Ramirez-Mares, 2014. Impact of
caffeine and coffee on our health. Trends Endocrinol.,
Metabo., 25: 489-492.
2. Ribeiro, V.S., A.E. Leitão, J.C. Ramalho and F.C. Lidon, 2014.
Chemical characterization and antioxidant properties of a
new coffee blend with cocoa, coffee silverskin and green
coffee minimally processed. Food Res. Int., 61: 39-47.
3. Pimentel, G.D., T.O. Micheletti, R.C. Fernandes and A. Nehlig,
2019. Coffee Intake and Obesity. In: Nutrition in the
Prevention and Treatment of Abdominal Obesity. Watson,
R.R. (Ed.). Elsevier, UK, pp: 329-351.
4. Mitchell, D.C., C.A. Knight, J. Hockenberry, R. Teplansky,
T.J. Hartmand, 2014. Beverage caffeine intakes in the U.S.
Food and Chem. Toxicol., 63: 136-142.
5. Ochiai, R., Y. Sugiura, Y. Shioya, K. Otsuka, Y. Katsuragi and
T. Hashiguchi, 2014. Coffee polyphenols improve peripheral
endothelial function after glucose loading in healthy male
adults. Nutr. Res., 34: 155-159.
6. Pimpley, V., S. Patil, K. Srinivasan, N. Desai and P.S. Murthy,
2020. The chemistry of chlorogenic acid from green coffee
and its role in attenuation of obesity and diabetes. Prep.
Biochem. Biotechnol., 10.1080/10826068.2020.1786699
7. Lee, L.W., M.W. Cheong, P. Curran, B. Yu and S.Q. Liu, 2015.
Coffee fermentation and flavor ‒ An intricate and delicate
relationship. Food Chem., 185: 182-191.
8. Giacalone, D., T.K. Degn, N. Yang, C. Liu, I. Fisk and
M. Münchow, 2019. Common roasting defects in coffee:
Aroma composition, sensory characterization and consumer
perception. Food Qual. Preference, 71: 463-474.
9. Muñoz, A.E., S.S. Hernández, A.R. Tolosa, S.P. Burillo and
M.O. Herrera, 2020. Evaluation of differences in the
antioxidant capacity and phenolic compounds of green and
roasted coffee and their relationship with sensory properties.
Food Sci. Technol., Vol. 128 10.1016/j.lwt.2020.109457
10. Baeza, G., M. Amigo-Benavent, B. Sarriá, L. Goya, R. Mateos
and L. Bravo, 2014. Green coffee hydroxycinnamic acids but
not caffeine protect human HepG2 cells against oxidative
stress. Food Res. Int., 62: 1038-1046.
11. Wachamo, H.L., Vol. 6, No. 4 2017. Review on Health Benefit
and Risk of Coffee Consumption. Med. Aromat. Plants,
12. Bordenave, N., L.B. Kock, M. Abernathy, J.C. Parcon,
A.A. Gulvady, B.J.W.v, Klinken and P. Kasturi 2015. Toward a
more standardised and accurate evaluation of glycemic
response to foods: Recommendations for portion size
calculation. Food Chem., 167: 229-235.
13. Augustin, L.S., C.W. Kendall, D.J. Jenkins, W.C. Willett and
., 2015. Glycemic index, glycemic load and
glycemic response: An International Scientific Consensus
Summit from the International Carbohydrate Quality
Consortium (ICQC). Nutr. Metab. Cardiovasc. Dis., 25: 795-815.
14. Hardy, D.S., J.T. Garvin and H. Xu, 2020. Carbohydrate quality,
glycemic index, glycemic load and cardiometabolic risks in
the US, Europe and Asia: A dose‒response meta-analysis.
Nutr. Metab. Cardiovasc. Dis., 30: 853-871.
15. Salari-Moghaddam, A., A.H. Keshteli, F. Haghighatdoost,
A. Esmaillzadeh and P. Adibi, 2019. Dietary glycemic index
and glycemic load in relation to general obesity and central
adiposity among adults. Clin. Nutr., 38: 2936-2942.
16. Schwingshackl, L. and G. Hoffmann, 2013. Long-term effects
of low glycemic index/load vs. high glycemic index/load diets
on parameters of obesity and obesity-associated risks: A
systematic review and meta-analysis. Nutr. Metab.
Cardiovasc. Dis., 23: 699-706.
17. Singh, A., P. Raigond, M.K. Lal, B. Singh and N. Thakur, 2020.
Effect of cooking methods on glycemic index and
bioaccessibility of potato (
carbohydrates. LWT-Food Sci. Technol., Vol. 127
18. Mann, J., J.H. Cummings, H.N. Englyst, T. Key and S. Lui
2007. FAO/WHO scientific update on carbohydrates in human
nutrition: Conclusions. Eur. J. Clin. Nutr., 61: S132-S137.
19. Gibson, N., H.C. Schönfeldt and B. Pretorius, 2011.
Development of a rapid assessment method for the
prediction of the glycemic index. J. Food Compos. Anal.,
Pak. J. Nutr., 19 (9): 420-429, 2020
20. Atkinson, F.S., K. Foster-Powell and J.C. Brand-Miller, 2008.
International tables of glycemic index and glycemic load
values: 2008. Diabetes Care, 31: 2281-2283.
21. Al-Mssallem, M.Q., 2014. The association between the
glycaemic index of some traditional saudi foods and the
prevalence of diabetes in Saudi Arabia: A review article.
J. Diabetes Metab., Vol. 5. 10.4172/2155-6156.1000452
22. Alkaabi, J.M., B. Al-Dabbagh, S. Ahmad, H.F. Saadi, S. Gariballa
and M. Al Ghazali, 2011. Glycemic indices of five varieties
of dates in healthy and diabetic subjects. Nutr. J., Vol. 10.
23. Farhat, A.G., S.R. Moukarzel, R.J. El-Said and C.F. Daher, 2010.
Glycemic index of commonly consumed lebanese mixed
meals and desserts. Asian J. Clin. Nutr., 2: 48-57.
24. Aston, L.M., J.M. Gambell, D.M. Lee, S.P. Bryant and S.A. Jebb,
2008. Determination of the glycaemic index of various
staple carbohydrate-rich foods in the UK diet. Eur. J. Clin.
Nutr., 62: 279-285.
25. AlGeffari, M.A., E.S. Almogbel, T.A. Homaidan, R. El-Mergawi
and I.A. Barrimaha, 2016. Glycemic indices, glycemic load and
glycemic response for seventeen varieties of dates grown in
Saudi Arabia. Ann. Saudi Med., 36: 397-403.
26. Brouns, F., I. Bjorck, K.N. Frayn, A.L. Gibbs, V. Lang, G. Slama
and T.M.S. Wolever, 2005. Glycaemic index methodology.
Nutr. Res. Rev., 18: 145-171.
27. Camps, G., M. Mars, C.d. Graaf and P.A. Smeets, 2016. Empty
calories and phantom fullness: a randomized trial studying
the relative effects of energy density and viscosity on gastric
emptying determined by MRI and satiety. Am. J. Clin. Nutr.,
28. Pribic, T., L. Hernandez, A. Nieto, C. Malagelada, A. Accarino
and F. Azpiroz, 2018. Effects of meal palatability on
postprandial sensations. Neurogastroenterology Motil.,
Vol. 30, No. 2 10.1111/nmo.13248
29. Farvid, M.S., F. Homayouni, M. Shokoohi, A. Fallah and
M.S. Farvid, 2014. Glycemic index, glycemic load and their
association with glycemic control among patients with type
2 diabetes. Eur. J. Clin. Nutr., 68: 459-463.
30. Marques, A.M., B.S. Linhares, R.D. Novaes, M.B. Freitas,
M.M. Sarandy and R.V. Gonçalves, 2020. Effects of the amount
and type of carbohydrates used in type 2 diabetes diets in
animal models: A systematic review. PLos ONE, Vol. 15, No. 6
31. Fernandez, M.A. and A. Marette, 2020. Dairy Products and
Diabetes: Role of Protein on Glycaemic Control. In: Milk and
Dairy Foods: Their Functionality in Human Health and
Disease. Givens, D.I. (Ed.). Academic Press, United States
32. Korat, A.V.A., Y. Li, F. Sacks, B. Rosner, W.C. Willett, F.B. Hu
and Q. Sun, 2019. Dairy fat intake and risk of type 2
diabetes in 3 cohorts of US men and women. Am. J. Clin.
Nutr., 110: 1192-1200.
33. Bataineh, M.F., 2002. Glycemic and Insulinemic Indices of
Certain Popular Arabic Sweets with Modified Fat Content.
Master Thesis, University of Jordan
34. Wallace, A.J., Eady, S.L. J.A. Willis, Scott, R.S., J.A. Monro and
C.M. Frampton, 2009. Variability in measurements of blood
glucose response to foods in human subjects is not reduced
after a standard breakfast. Nutr. Res., 29: 238-243.
35. Wallace, A.J., J.A. Monro, R.C. Brown, C.M. Framptond, 2008.
A glucose reference curve is the optimum method to
determine the glycemic glucose equivalent values of foods in
humans. Nutr. Res., 28: 753-759.
36. Powers, M.A., R.M. Cuddihy, D. Wesley and B. Morgan,
2010. continuous glucose monitoring reveals different
glycemic responses of moderate- vs high-carbohydrate lunch
meals in people with type 2 diabetes. J. Am. Diabet. Assoc.,
37. Cai, X., L. Xia, Y. Pan, D. He, H. Zhu, T. Wei and Y. He, 2019.
Differential role of insulin resistance and $-cell function in the
development of prediabetes and diabetes in middle-aged
and elderly Chinese population. Diabetology Metab.
Syndrome, Vol. 11, No. 24 10.1186/s13098-019-0418-x
38. The Expert Committee on the Diagnosis and Classification of
Diabetes Mellitus, 2003. Report of the expert committee on
the diagnosis and classification of diabetes mellitus. Diabetes
Care, 26: S5-S20.
39. Chia, C.W., J.M. Egan and L. Ferrucci, 2018. Age-related
changes in glucose metabolism, hyperglycemia and
cardiovascular risk. Circ. Res., 123: 886-904.
40. Jia, T., X. Huang, A.R. Qureshi, H. Xu and J. Ärnlöv
Validation of insulin sensitivity surrogate indices and
prediction of clinical outcomes in individuals with and
without impaired renal function. Kidney Int., 86: 383-391.
41. Antuna-Puente, B., E. Disse, R. Rabasa-Lhoret, M. Laville,
J. Capeau and J.P. Bastard, 2011. How can we measure
insulin sensitivity/resistance? [Comment mesurer la
sensibilité/résistance à linsuline?]. Diabetes Metab.,
42. Kim, S.H., A. Silvers, J. Viren and G.M. Reaven, 2016.
Relationship between insulin sensitivity and insulin
secretion rate: not necessarily hyperbolic. Pathophysiology,
43. Tohidi, M., A. Ghasemi, F. Hadaegh, A. Derakhshan, A. Chary
and F. Azizi, 2014. Age- and sex-specific reference values for
fasting serum insulin levels and insulin resistance/sensitivity
indices in healthy Iranian adults: Tehran lipid and glucose
study. Clin. Biochem., 47: 432-438.
44. Song, S., H.Y. Paik and Y. Song, 2012. High intake of whole
grains and beans pattern is inversely associated with insulin
resistance in healthy Korean adult population. Diabetes Res.
Clin. Pract., 98: E28-E31.
Pak. J. Nutr., 19 (9): 420-429, 2020
45. Dam, R.M.v., J.M. Dekker, G. Nijpels, C.D.A. Stehouwer,
L.M. Bouter and R.J. Heine, 2004. Coffee consumption and
incidence of impaired fasting glucose, impaired glucose
tolerance and type 2 diabetes: the Hoorn study. Diabetologia,
46. Whitehead, N. and H. White, 2013. Systematic review of
randomised controlled trials of the effects of caffeine or
caffeinated drinks on blood glucose concentrations and
insulin sensitivity in people with diabetes mellitus. J. Hum.
Nutr. Diet., 26: 111-125.
47. Louie, J.C.Y., F. Atkinson, P. Petocz and J.C.B rand-Miller, 2008.
Delayed effects of coffee, tea and sucrose on postprandial
glycemia in lean, young, healthy adults. Asia Pac. J. Clin. Nutr.,
48. Moisey, L.L., S. Kacker, A.C. Bickerton, L.E. Robinson and
T.E. Graham, 2008. Caffeinated coffee consumption impairs
blood glucose homeostasis in response to high and low
glycemic index meals in healthy men. Am. J. Clin. Nutr.,
49. Sacramento, J.F., F.O. Martins, T. Rodrigues, P. Matafome,
M.J. Ribeiro, E. Olea and S.V. Conde, 2020. A2 adenosine
receptors mediate whole-body insulin sensitivity in a
prediabetes animal model: primary effects on skeletal muscle.
Front. Endocrinol., 10.3389/fendo.2020.00262
50. Shi, X., W. Xue, S. Liang, J. Zhao and X. Zhang, 2016. Acute
caffeine ingestion reduces insulin sensitivity in healthy
subjects: a systematic review and meta-analysis. Nutr. J.,
Vol. 15 10.1186/s12937-016-0220-7
51. Guarino, M.P., M.J. Ribeiro, J.F. Sacramento and S.V. Conde,
2013. Chronic caffeine intake reverses age-induced insulin
resistance in the rat: effect on skeletal muscle Glut4
transporters and AMPK activity. AGE, 35: 1755-1765.
52. Silva, L.A.d., J. Wouk, V.M.R. Weber, C.d.L. Eltchechem and
., 2017. Mechanisms and biological effects
of Caffeine on substrate metabolism homeostasis: A
systematic review. J. Applied Pharm. Sci., 7: 215-221.
53. Robinson, L.E., S. Savani, D.S. Battram, D.H. McLaren,
P. Sathasivam and T.E. Graham, 2004. Caffeine ingestion
before an oral glucose tolerance test impairs blood glucose
management in men with type 2 diabetes. J. Nutr.,
54. Lee, S.J., R. Hudson, K. Kilpatrick, T.E. Graham and R. Ross,
2005. Caffeine ingestion is associated with reductions in
glucose uptake independent of obesity and type 2 diabetes
before and after exercise training. J. Diabetes Care,
55. Akash, M.S.H., K. Rehman and S. Chen, 2014. Effects of coffee
on type 2 diabetes mellitus. Nutrition, 30: 755-763.
56. Campbell, B., C. Wilborn, P.L. Bounty, L. Taylor and
, 2013. International society of sports
nutrition position stand: energy drinks. J. Int. Soc. Sports
57. Reis, C.E.G., J.G. Dórea and T.H.M.da Costa, 2019. Effects of
coffee consumption on glucose metabolism: A systematic
review of clinical trials. J. Traditional Complementary Med.,
58. Akash, M.S.H., K. Rehman, H. Sun and S. Chen, 2013.
Interleukin-1 receptor antagonist improves normoglycemia
and insulin sensitivity in diabetic Goto-Kakizaki-rats.
Eur. J. Pharmacol., 701: 87-95.
59. Alagbonsi, A.I., T.M. Salman, H.M. Salahdeen and A.A. Alada,
2016. Effects of adenosine and caffeine on blood glucose
levels in rats. Niger. J. Exp. Clin. Biosci., 4: 35-41.
60. Ohnaka, K., M. Ikeda, T. Maki, T. Okada and T. Shimazoe
2012. Effects of 16-week consumption of caffeinated and
decaffeinated instant coffee on glucose metabolism in a
randomized controlled trial. J. Nutr. Metab., Vol. 2012
61. Ärnlöv, J., B. Vessby and U. Risérus, 2004. Coffee consumption
and insulin sensitivity. JAMA, 291: 1199-1201.
62. Wu, T., W.C. Willett, S.E. Hankinson and E. Giovannucci, 2005.
Caffeinated coffee, decaffeinated coffee and caffeine in
relation to plasma C-peptide levels, a marker of insulin
secretion, in U.S. women. Diabetes Care, 28: 1390-1396.
63. Smith, B., D.L. Wingard, T.C. Smith, D. Kritz-Silverstein and
E. Barrett-Connor, 2006. Does coffee consumption reduce the
risk of type 2 diabetes in individuals with impaired glucose?
Diabetes Care, 29: 2385-2390.
64. Kempf, K., C. Herder, I. Erlund, H. Kolb and S. Martin
2010. Effects of coffee consumption on subclinical
inflammation and other risk factors for type 2 diabetes: A
clinical trial. Am. J. Clin. Nut., 91: 950-957.
65. Cherniack, E.P., N. Buslach and H.F. Lee, 2018. The potential
effects of caffeinated beverages on insulin sensitivity.
J. Am. Coll. Nutr., 37: 161-167.
66. Williamson, G., 2020. Protection against developing type 2
diabetes by coffee consumption: assessment of the role of
chlorogenic acid and metabolites on glycaemic responses.
Food and Funct., 11: 4826-4833.
67. Pham, N.M., A. Nanri, K. Yasuda, K. Kurotani and Keisuke
., 2015. Habitual consumption of coffee and
green tea in relation to serum adipokines: a cross-sectional
study. Eur. J. Nutr., 54: 205-214.
68. Hiltunen, L.A., 2006. Are there associations between coffee
consumption and glucose tolerance in elderly subjects?
Eur. J. Clin. Nutr., 60: 1222-1225.
69. Beaudoin, M.S., L.E. Robinson and T.E. Graham, 2011. An oral
lipid challenge and acute intake of caffeinated coffee
additively decrease glucose tolerance in healthy men. J. Nutr.,
70. Feinberg, L.J., H. Sandberg, O.D. Castro and S. Bellet, 1968.
Effects of coffee ingestion on oral glucose tolerance curves in
normal human subjects. Metabolism, 17: 916-922.
Pak. J. Nutr., 19 (9): 420-429, 2020
71. Meng, S., J. Cao, Q. Feng, J. Peng and Y. Hu, 2013. Biological
values of acupuncture and chinese herbal medicine: impact
on the life science Evidence-Based Complementary Altern.
Med., Vol. 2013 10.1155/2013/801457
72. Thom, E., 2007. The effect of chlorogenic acid enriched coffee
on glucose absorption in healthy volunteers and its effect on
body mass when used long-term in overweight and obese
people. J. Int. Med. Res., 35: 900-908.
73. Gavrieli, A., E. Fragopoulou, C.S. Mantzoros and
M. Yannakoulia, 2013. Gender and body mass index
modify the effect of increasing amounts of caffeinated
coffee on postprandial glucose and insulin concentrations;
a randomized, controlled, clinical trial. Metabolism,
74. Pham, N.M., A. Nanri, T. Kochi, K. Kuwahara and
., 2014. Coffee and green tea consumption is
associated with insulin resistance in Japanese adults.
Metabolism, 63: 400-408.
75. Battram, D.S., T.E. Graham, E.A. Richter and F. Dela, 2005. The
effect of caffeine on glucose kinetics in humans ‒ influence of
adrenaline. J. Physiol., 569: 347-355.
76. Krebs, J.D., A. Parry-Strong, M. Weatherall, R.W. Carroll and
M. Downie, 2012. A cross-over study of the acute effects
of espresso coffee on glucose tolerance and insulin sensitivity
in people with type 2 diabetes mellitus. Metabolism,
77. Kahale, K.H., C. Tranchant, S. Pakzad and A.G. Farhat, 2015.
Effect of sumac spice, Turkish coffee and yerba mate tea
on the postprandial glycemic response to Lebanese
mankoucheh. Nutr. Food Sci., 45 : 433 -447.
78. Beam, J.R., A.L. Gibson, C.M. Kerksick, C.A. Conn, A.C. White
and C.M. Mermier, 2015. Effect of post-exercise caffeine and
green coffee bean extract consumption on blood glucose
and insulin concentrations. Nutrition, 31: 292-297.
79. Wylie-Rosett, J. and L.M. Delahanty, 2017. The Role of Diet in
the Prevention and Treatment of Diabetes. In: Nutrition in
the Prevention and Treatment of Disease. Coulston, A.M.,
C.J. Boushey and L.M. Delahanty (Eds.). Academic Press,
United States pp: 691-707.
80. American Diabetes Association, 2012. Diagnosis and
classification of diabetes mellitus. Diabetes Care, 35: S64-S71.
81. American Diabetes Association, 2012. Standards of Medical
Care in Diabetes. Diabetes Care, 35: S11-S63.
82. Ley, S.H., O. Hamdy, V. Mohan and F.B. Hu, 2014. Prevention
and management of type 2 diabetes: Dietary components
and nutritional strategies. Lancet, 383: 1999-2007.
83. Kwok, M.K., G.M. Leung and C.M. Schooling, 2016.
Habitual coffee consumption and risk of type 2 diabetes,
ischemic heart disease, depression and Alzheimers
disease: a Mendelian randomization study. Sci. Rep., Vol. 6,
84. Sarriá, B., S. Martínez-López, R. Mateos and L. Bravo-Clemente,
2016. Long-term consumption of a green/roasted coffee
blend positively affects glucose metabolism and insulin
resistance in humans. Food Res. Int., 89: 1023-1028.
85. Lane, J.D., 2011. Caffeine, glucose metabolism and type 2
diabetes. J. Caffeine Res., 1: 23-28.
86. Ding, M., S.N. Bhupathiraju, M. Chen, R.M. van Dam and
F.B. Hu, 2014. Caffeinated and decaffeinated coffee
consumption and risk of type 2 diabetes: A systematic
review and a dose-response meta-analysis. Diabetes Care,
87. Dam, R.M.V., W.C. Willett, J.E. Manson and F.B. Hu, 2006.
Coffee, caffeine and risk of type 2 diabetes: A prospective
cohort study in younger and middle-aged U.S. women.
Diabetes Care, 29: 398-403.
88. Alkaabi, J., B. Al-Dabbagh, H. Saadi, S. Gariballa and J. Yasin,
2013. Effect of traditional arabic coffee consumption on the
glycemic index of khalas dates tested in healthy and diabetic
subjects. Asia Pac. J. Clin. Nutr., 22: 565-573.
89. Zhang, Y., E.T. Lee, L.D. Cowan, R.R. Fabsitz and B.V. Howard,
2011. Coffee consumption and the incidence of type 2
diabetes in men and women with normal glucose
tolerance: The strong heart study. Nutr. Metab. Cardiovasc.
Dis., 21: 418-423.
90. Hamer, M., D.R. Witte, A. Mosdøl, M.G. Marmot and
E.J. Brunner, 2008. Prospective study of coffee and tea
consumption in relation to risk of type 2 diabetes mellitus
among men and women: The Whitehall II study. Br. J. Nutr.,
91. Loopstra-Masters, R.C., A.D. Liese, S.M. Haffner,
L.E. Wagenknecht and A.J. Hanley, 2011. Associations
between the intake of caffeinated and decaffeinated coffee
and measures of insulin sensitivity and beta cell function.
Diabetologia, 54: 320-328.
92. Alperet, D.J., S.A. Rebello, E.Y.H. Khoo, Z. Tay and S.S.Y. Seah,
2020. 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.,
93. Natella, F. and C. Scaccini, 2012. Role of coffee in modulation
of diabetes risk. Nutr. Rev., 70: 207-217.
94. Zaharieva, D.P. and M.C. Riddell, 2013. Caffeine and glucose
homeostasis during rest and exercise in diabetes mellitus.
Applied Physiol. Nutr. and Metab., 38: 813-822.
95. Bidel, S., G.Hu, J. Sundvall, J. Kaprio, J. Tuomilehto, 2006.
Effects of coffee consumption on glucose tolerance, serum
glucose and insulin levels - A cross-sectional analysis. Horm.
Metab. Res., 38: 38-43.
96. Bhatti, K. Salman, OKeefe, H. James, Lavie and J. Carl, 2013.
Coffee and tea: perks for health and longevity? Curr. Opin.
Clin. Nutr. Metab. Care, 16: 688-697.
Pak. J. Nutr., 19 (9): 420-429, 2020
97. Chu, Y.F., Y. Chen, R.M. Black, P.H. Brown, B.J. Lyle, R.H. Liu and
B. Ou, 2011. Type 2 diabetes-related bioactivities of coffee:
Assessment of antioxidant activity, NF-6B inhibition and
stimulation of glucose uptake. Food Chem., 124: 914-920.
98. Asfaw, G. and M. Tefera, 2020. Total polyphenol content of
green, roasted and cooked Harar and Yirgacheffee Coffee,
Ethiopia. J. Applied Sci. Environ. Manage., 24: 187-192.
99. Higdon, J.V. and B. Frei, 2006. Coffee and health: A review
of recent human research. Crit. Rev. Food Sci. Nutr.,
100. Gao, F., Y. Zhang, S. Ge, H. Lu and R. Chen
., 2018. Coffee
consumption is positively related to insulin secretion in the
shanghai high-risk diabetic screen (SHiDS) study. Nutr.
Metab., Vol. 84 10.1186/s12986-018-0321-8