one aspect of the present invention is that caffeine is detrimental to glucose uptake in human skeletal muscle cells of healthy subjects ( i . e . non - diabetic lean males ). examples 1 , 2 , and 17 illustrate this aspect of the invention in more detail . this aspect of the invention demonstrates that caffeine ingestion affects glucose metabolism . further , a caffeine - free diet is beneficial to insulin &# 39 ; s action . further still , compounds that act in the opposite manner to caffeine ( i . e . adenosine receptor agonists ) promote insulin &# 39 ; s actions . another aspect of the present invention is that caffeine is detrimental to glucose uptake in human skeletal muscle cells of obese and diabetic subjects . examples 5 , 6 , 7 , 8 , 9 , 11 , 16 , 18 and 19 describe this aspect of the invention in more detail . the result is that diabetic and obese patients will make effective nutritional choices for the treatment of diabetes and obesity . further , people with a susceptibility to diabetes and obesity can make effective nutritional choices for the prevention of type 2 diabetes and obesity . for example , it is beneficial for diabetics to avoid caffeine . caffeine is present in many “ everyday ” products such as coffee , tea , weight loss products , energy drinks , soft drinks and pharmaceuticals , especially remedies for the common cold . diabetics should avoid caffeine - containing products , and if possible choose caffeine - free / caffeine - reduced weight loss products , energy drinks , soft drinks and pharmaceuticals . further , diabetics , obese patients and those susceptible to diabetes and obesity should adopt a system of health management to avoid / minimize caffeine consumption . further , another aspect of the present invention relates to a labeling system for diabetics and people susceptible to diabetes comprising labeling food and pharmaceutical products that are caffeine - free / caffeine - reduced and low in simple sugars as safe for diabetics . another aspect of the present invention is that decaffeinated coffee increases glucose uptake . example 3 describes this aspect of the invention in more detail . coffee is comprised of many compounds , caffeine constituting a mere 1 - 3 % of the content . the benefits of this aspect of the invention are that ( 1 ) decaffeinated coffee contains a compound or compounds that aids glucose uptake , ( 2 ) consumption of decaffeinated coffee helps to treat or prevent diabetes and obesity , and ( 3 ) coffee is a biological source of an adenosine receptor agonist useful for increased uptake of glucose . another aspect of the present invention is that adenosine , adenosine analogues , derivatives and conjugates thereof promote glucose uptake in skeletal muscle in healthy , diabetic and obese subjects . examples 3 and 16 describe this aspect of the invention in more detail . as a result , adenosine , adenosine analogues , derivatives and conjugates thereof can be used to prevent and treat diabetes and obesity . another aspect of the invention relates to the role of adenosine receptor antagonists during exercise . examples 10 and 11 describe this aspect of the invention . as a result , the use of adenosine receptor agonists in sports drinks , is beneficial for getting glucose into the muscle in recovery from exercise . another aspect of the invention relates to the role of adenosine receptor antagonists on blood response to high and low index glycemic foods in non - diabetic and diabetic volunteers . examples 17 and 18 describe this aspect of the invention . the result is that diabetic patients will make effective nutritional choices for the treatment of diabetes . further , people with a susceptibility to diabetes can make effective nutritional choices for the prevention of type 2 diabetes . the methods and materials employed in this invention are common to those skilled in the art . the methods and materials for the hyperinsulinemic euglycemic glucose clamp test are found in greer et al ., 2001 . the methods and materials for the oral glucose tolerance test ( ogtt ) are described in graham et al ., 2001 . caffeine ingestion decreases glucose disposal during hyperinsulinemic euglycemic clamp in humans nine , lean sedentary males underwent two hyperinsulinemic euglycemic clamp sessions , one following caffeine ingestion ( 5 mg / kg ) and one following placebo ( dextrose ). trials were separated by one week . prior to each clamp session , subjects withdrew from methylxanthine containing products for 48 hours . following caffeine ingestion , glucose disposal was 6 . 38 +/− 0 . 76 mg / kg / min compared with 8 . 42 +/− 0 . 63 mg / kg / min in the placebo . this represents a 24 % decrease in glucose disposal following adenosine receptor antagonism by caffeine . furthermore caffeine ingestion resulted in a 35 % decrease in carbohydrate storage compared to placebo and is consistent with the decreased glucose uptake observed with caffeine administration . since skeletal muscle is the most likely site for insulin - mediated glucose disposal , these data suggest that adenosine plays a role in regulating glucose uptake in human skeletal muscle . caffeine ingestion increases circulating in humans during an oral glucose tolerance test young , fit , adult males ( n = 18 ) underwent two oral glucose tolerance tests ( ogtt ). the subjects ingested caffeine ( 5 mg / kg ) or placebo ( double blind ) and one hour later , ingested 75 g of dextrose . prior to the ogtt there were no differences between or within trials in circulating serum insulin , or c peptide , or blood glucose or lactate . following the ogtt all of these parameters increased ( p ≦ 0 . 05 ) for the duration of the ogtt . caffeine ingestion resulted in an increase ( p ≦ 0 . 05 ) in serum fatty acids , glycerol and plasma epinephrine . during the ogtt these decreased to match those of the placebo trial . in the caffeine trial the serum insulin and c peptide concentrations were significantly greater ( p ≦ 0 . 05 ) than for placebo for the last 90 minutes of the ogtt ( see fig2 and 3 ) and the area under the curve for both measures were 60 and 37 % greater ( p ≦ 0 . 05 ) respectively . this prolonged , greater elevation in insulin did not result in a lower blood glucose level ( see fig1 ); there were no differences between trials . the data support the hypothesis that caffeine ingestion impairs glucose disposal . further , the data suggests this is due to adenosine receptor antagonism in skeletal muscle . impaired response to an oral glucose tolerance test following ingestion of caffeine in alkaloid form or as a component of coffee ten healthy male subjects , who were not regular caffeine users , underwent an oral glucose tolerance test on four occasions following the ingestion of either pure alkaloid caffeine capsules ( 5 mg / kg ) ( ac ), caffeinated coffee ( cc ), decaffeinated coffee , or placebo capsules ( pl ). venous blood samples were taken at − 30 , 0 ( treatment given ), 60 ( ogtt administered ), 75 , 90 , 120 , 150 and 180 minutes and were analyzed for glucose , insulin , c peptide , glycerol , free fatty acids and lactate . area under the curve ( auc ) were calculated for the two hours of the ogtt . as previously seen , ac demonstrated a higher auc for insulin ( see fig5 ) than both pl ( p & lt ; 0 . 002 ) and dc ( p & lt ; 0 . 001 ) respectively . as well , insulin auc for cc showed a similar trend to ac , approaching a significantly higher insulin auc than dc ( p & lt ; 0 . 08 ). auc for peptide c ( see fig6 ) demonstrated similar results to insulin , again with ac showing higher values than both pl ( p & lt ; 0 . 02 ) and dc ( p & lt ; 0 . 001 ) and cc approaching significantly higher values that dc ( p & lt ; 0 . 08 ). auc for glucose with ac was higher than both cc ( p & lt ; 0 . 04 ) and dc ( p & lt ; 0 . 01 ) respectively and cc was higher that dc ( p = 0 . 05 ). as well , pl demonstrated higher auc for glucose than dc ( p & lt ; 0 . 02 ) see fig4 . in conclusion , it appears than cc can elicit a similar insulin insensitivity as observed with ac , but to a lesser extent . these results also suggest that some component of coffee may enhance insulin - mediated glucose uptake in resting humans . this component acts as an adenosine receptor agonist . the purpose of this study was to investigate the presence of a 1 and a 2 adenosine receptors ( ar ) in rat and human skeletal muscle . adenosine receptor - stimulated adenylate cyclase activity studies were conducted to determine camp responses in the presence of ar agonists using rat skeletal muscle homogenates . subsequently , western blotting experiments were conducted to identify the a 1 and a 2 receptor proteins in rodent and human skeletal muscle samples . in the initial experiments , neca ( an a 2 ar agonist ) produced a significant 7 . 5 - fold increase in camp production in rat oxidative muscle homogenates with no effect on glycolytic samples . there was little effect of r - pia ( an a 1 ar agonist ) on camp levels in any fiber type . western blotting revealed a 1 and a 2 ar protein bands in rat and human skeletal muscle samples . a 1 and a 2a expression was observed in similar amounts in both oxidative and glycolytic rodent fibers . a 2a expression was highest in the liver compared to muscle and heart homogenates . both rodent oxidative and glycolytic skeletal muscle homogenates had a significantly greater a 1 and a 2 expression compared to heart . in conclusion , both receptor subtypes appear to be present in oxidative and glycolytic muscle fibers in rodents and both receptor subtypes appear to be present in human skeletal muscle . caffeine ingestion increases circulating insulin in obese males during an oral glucose tolerance test four young , obese ( bmi & gt ; 30 ) nondiabetic males , underwent an ogtt similar to example 2 . when lean males ( n = 18 ) underwent ogtt with and without caffeine ingestion the aucs for glu were 168 and 208 mm / 2 h , respectively . the comparable data for the obese males were very similar ( 167 and 229 mm / 2 h ). however , there were marked differences for insulin : the lean males had aucs of 3274 and 5242 uu / ml / 2h for placebo and caffeine respectively , while comparable data for the obese males were 6938 and 10 , 968 uu / ml / 2 h . the obese subjects had an insulin response to an ogtt that was over 100 % greater than that of the lean subjects , and the insulin resistance induced by caffeine ingestion was twice as large . effects of caffeine ingestion on the insulin response in humans during an oral glucose tolerance test before and after a weight loss program six , obese ( bmi = 30 - 38 kg / m2 ) men performed an ogtt one hour after ingesting caffeine ( 5 mg / kg ) or placebo ( p ). the two ogtt &# 39 ; s were repeated after a twelve week nutrition - exercise intervention during which time subjects abstained from caffeine and lost 3 - 12 kg . there were no differences among the four trials in insulin , c - peptide or glucose prior to the ogtt . prior to the twelve week intervention , caffeine ingestion resulted in a greater ( p = 0 . 043 ) insulin response during the ogtt , although there were no differences in blood glucose . following the intervention there was no detectable change in the ogtt response for either placebo or caffeine . similarly , caffeine still resulted in a greater ( p = 0 . 056 ) increase in insulin during the ogtt compared to placebo . the intervention successfully lowered body weight , but failed to improve the insulin response to glucose ingestion , and the caffeine ingestion continued to exaggerate this response . effect of caffeine on the insulin / glucose response to an ogtt in obese , resting males young , sedentary , obese males ( n = 28 ) underwent two ogtt &# 39 ; s ingesting caffeine ( 5 mg / kg ) or placebo followed by 75 g of dextrose one hour later . prior to the ogtt there were no differences between or within trials in insulin or glucose levels . caffeine resulted in significantly greater ( p & lt ; 0 . 05 ) glucose and insulin for the last 90 minutes and 105 minutes respectively of the ogtt . the area under the curve during the ogtt was greater following caffeine for both insulin ( 9455 . 8 - uiu / ml / 2h (□˜ 640 . 7 ) and glucose ( 260 . 1 mm / 2h (− 22 . 4 ) in comparison to placebo ( 7037 . 9 uiu / ml / 2h (□˜ 631 . 5 and 188 . 5 mm / 2h (□˜ 25 . 3 ) respectively ( p & lt ; 0 . 05 ). the results indicate that caffeine ingestion may exaggerate insulin resistance associated with obesity . characterization of the impact of adenosine receptor antagonism on obese and type 2 diabetics , with emphasis on the ability of caffeine to generate insulin resistance . groups of obese ( bmi & gt ; 30 ) ( n = 18 ), and type 2 diabetic ( n = 18 ) males , age 18 - 30 years old are undergoing two ogtts , with and without caffeine ingestion one hour prior to the ogtt . the results will be compared to the current data base ; containing data ( 28 , 40 ) collected in an identical fashion for 30 lean ( bmi of less than 25 ) males age 18 - 30 years . lean subjects have bmi of less than 25 , the obese are class i ( bmi 30 - 34 ), abdominal obese ( waist circumference & gt ; 100 cm ) and the diabetics have the same anthropometry . the diabetics are volunteers who have been well controlled for a year , with glycosylated hemoglobin levels between 6 . 5 - 9 . 5 % for at least three months . they have similar levels of obesity , are not insulin - dependent , and are not on oral hypoglycemic agents , but rather diet - controlled . their participation is medically approved and they are screened for hypertension and angina . the area under the curve for insulin and c - peptide is greater for the obese and even greater for the diabetic subjects . following caffeine ingestion the area under the curves for insulin and c - peptide are increased in the lean subjects . caffeine causes an even greater response in these parameters for the obese and diabetic subjects . data also includes plasma catecholamines , methylxanthines , ffa , and glycerol . the subjects of this trial are lean , obese and obese males with type 2 diabetes ( n = 8 each , age 18 - 30 years ) which have had their exercise habits , diet and caffeine consumption regulated . all subjects are sedentary ( weekly activity of less than one hour ). for one month prior to the study , subjects are monitored to establish that their exercise habits are regular , they are weight stable and their diet is energy , macronutrient and caffeine stable . they are monitored to ensure that they maintain these patterns for the following three months . in a double - blind , crossover design they consume either caffeinated or decaffeinated coffee for one month with the two trials separated by a one month ‘ washout ’ period . subjects are provided with packets of ground coffee and brewing instructions . for the caffeinated treatment , the coffee packets deliver 4 . 5 mg / kg of caffeine in their coffee ( 2 mugs of coffee ) twice a day . at 0 , 1 and 4 weeks of each trial the subjects undergo an ogtt 1 hour following ingestion of 2 mugs of their prescribed coffee . no exercise is performed within two days of the ogtt and carbohydrate ingestion is regulated . muscle biopsies are taken before and after each ogtt . blood samples are analyzed and biopsies are analyzed for a1 and a2a receptor protein and mrna , camp , glycogen and irtk activity , irs - 1 associated pi3k , akt and gsk - 3 . prior to treatments , the obese and diabetic subjects are insulin resistive and have a greater insulin response to caffeine . habitual ingestion of coffee upregulates a1 receptors progressively over the month . during the transition ( i . e ., at one week ), a decrease in the insulin response is observed . upon habituation ( one month ), the response returns to normal . caffeine impairs glucose uptake but not insulin signaling in rested and exercised human skeletal muscle the role of adenosine in regulating insulin - stimulated glucose uptake in human skeletal muscle is not known . we investigate the effects of caffeine , a non - selective adenosine receptor antagonist , on skeletal muscle glucose uptake during a 100 minute euglycemic - hyperinsulinemic ( 100 μu / ml ) clamp . on two occasions , seven males performed one hour one - legged knee extensor exercise three hours before the clamp . caffeine ( 5 mg / kg ) or placebo was administered in a randomized , double blind fashion one hour before the clamp . whole body glucose disposal was reduced ( p & lt ; 0 . 05 ) in caffeine ( 37 . 5 +/− 3 . 1 μmol / min / kg ) vs . placebo ( 54 . 1 +/− 2 . 9 μmol / min / kg ). total ( area under the curve ) insulin - stimulated glucose uptake ( arterio - venous concentration difference × blood flow ) was higher ( p & lt ; 0 . 05 ) in the exercised ( 63 . 3 +/− 13 . 1 mmol / 100 min ) than rested ( 37 . 0 +/− 6 . 7 mmol / 100 min ) leg . however caffeine reduced ( p & lt ; 0 . 05 ) total insulin - stimulated glucose uptake equally in exercised ( 32 . 9 +/− 3 . 7 mmol / 100 min ) and rested ( 17 . 9 +/− 6 . 2 mmol / 100 min ) legs . insulin increased insulin receptor tyrosine kinase ( irtk ), insulin receptor substrate 1 - associated phospatidylinositol 3 - kinase ( p13k ) activities and serine phosphorylation of akt significantly , but similarly in rested and exercised legs . furthermore , insulin decreased glycogen synthase kinase - 3 ( gsk - 3 ) activity equally in rested and exercised legs . however , caffeine had no effect on insulin - stimulated irtk , p13k , akt , or gsk - 3 in relaxed or exercised legs . we conclude in humans 1 ) caffeine impairs insulin stimulated glucose uptake in rested and exercised skeletal muscles , and 2 ) caffeine - induced impairment of insulin - stimulated muscle glucose uptake is not accompanied by alterations in irtk , p13k , akt or gsk - 3 . effect of exercise training on the response to adenosine receptor antagonism and its association with alterations in glucose management lean , sedentary males , and obese males with and without type 2 diabetes ( n = 8 each ) are performing a 12 - week , exercise training program . subjects are selected to have similar initial fitness levels ( vo 2 max ) and diet and caffeine habits are controlled throughout the study . during the pretreatment period , subjects consume a weight maintenance diet ( 55 % carbohydrate , 20 % protein , 25 % fat ). their body composition is assessed for total adiposity as well as visceral and subcutaneous fat before and after the treatment by magnetic resonance imaging ( mri ). the exercise program is supervised and consists of walking or running on a treadmill at 40 - 60 % of hr reserve for 60 minutes five times per week . subjects increase their energy intake to keep their weight stable to minimize changes in adipose tissue . thus , major alterations in metabolic responses are more likely attributed to training adaptations in muscle . euglycemic - hyperinsulinemic clamp tests with and without caffeine are performed before and after the training program ( those after the training are performed at least 48 hours after the last exercise ). muscle biopsies are taken before and after each clamp and analyzed . insulin sensitivity increases as does a1 receptors . the relative improvement is greatest in the type 2 diabetics and least in the lean subjects . male sprague - dawley rats are used in all the following examples . soleus muscle strips are incubated as described by bonen et al ( 1992 ), wilkes and bonen ( 2000 ) and bonen et al ( 1994 ) to determine glucose transport . basal and insulin - stimulated 3 - o - methyl glucose transport ( 3mgt ) is examined in a dose dependent ( 0 - 10 nm ) manner during a 10 minute incubation period in appropriate buffer ( bonen et al ., 1994 ). comparison of this dose - response relationship of insulin , and the a1 agonist cpa , and a2 agonist dpma on 3mgt is conducted . 3mgt rates are linear for up to 20 minutes . the 10 minute period is therefore a convenient time point to acquire sufficient counts in the muscle at a reasonable cost of using radiolabelled 3mgt . optimal stimulating concentrations of insulin , cpa , and dpma are established for 3mgt . insulin stimulated 3mgt is inhibited by ly29004 , an inhibitor of pi3 - kinase , 2 ) cpa - and dpma - induced increases in 3mgt are also inhibited by ly29004 , and 3 ) exposure to these stimulators alone or in combination have additive effect on 3mgt . effect of adenosine on membrane - bound glut 4 translocation and intrinsic activity the optimal glucose transport stimulating concentrations of insulin , cpa and dpma , are used to determine the increase , or lack thereof , in surface glut 4 using the method of radiolabelling the surface glut 4 with bis - mannose photolabel which has been used successfully by bonen et al ( 1992 ), han et al . ( 1998 ) and wilkes and bonen ( 2000 ) and others ( etgen et al ., 1996 ; lund et al ., 1995 ). with this procedure 3 h - bis - mannose ( 2 - n - 4 ( 1 - azi - 2 , 2 , 2 - trifluoroethyl )- benzoyl - 1 , 3 - bis -( d - mannose - 4 - yloxy )- 2 - propylamine ) ( atb -[ 2 - 3 h ] bmpa ) is provided to isolated muscles exposed to one of the treatments . the muscle is frozen (− 80 ° c . ), solubilized crude membranes are prepared ( han and bonen , 1998 ) and glut 4 is then immunoprecipitated with affinity purified anti - glut 4 to separate it from surface glut 1 that is also labeled . sds / page is used to separate glut 4 and remaining proteins . then the gel is cut into 4 mm slices which are solubilized and counted for 3 h . these experiments are designed to determine whether insulin and the a1 and a2 agonists translocate and / or activate glut 4 . in many experiments , the fold increases in surface glut 4 and 3mgt by insulin and by contracting muscle are nearly identical ( etgen et al ., 1996 , lund et al ., 1995 , reynolds et al ., 1997 ). thus , by combining the observations on glucose transport and surface glut 4 one can ascertain whether 3mgt increments in muscle are due to increases in surface glut 4 ( i . e . same fold increase in 3mgt and surface detectable glut 4 ). a mismatch in the fold increases in these responses , indicates that the activity of surface detectable glut 4 has been altered . this basic approach is commonly used to ascertain if there is a change in intrinsic activity of surface glut 4 ( bonen et al ., 1992 ; han and bonen , 1998 ; wilkes and bonen , 2000 ; hansen et al ., 1998 ). the demonstration of a 1 : 1 relationship between glucose transport and surface glut 4 accumulation by insulin , cpa and dpma , leads to additional experiments to identify insulin - sensitive and cpa and dpma - sensitive intracellular glut 4 pools . han and bonen ( 1998 ) and lemieux et al . ( 2000 ) have experience with various muscle fractionation procedures and identification of intracellular glut 4 pools using a variety of marker proteins . these experiments potentially reveal novel means of stimulating glut 4 translocation from insulin - insensitive pools . determination of the signaling proteins associated with glut 4 translocation which are activated by adenosine experiments with insulin , cpa and dpma are performed in isolated muscles using optimal stimulating concentrations to determine which signaling proteins are activated . for this purpose , isolated rodent muscles are incubated with either basal or maximal insulin concentrations with and without either cpa or dpma . glucose transport is determined by 3mgt , measured over 10 minutes . the muscle samples are analyzed for irtk , irs - 1 associated p13 kinase , p38 map kinase and akt activities . the critical exposure time to activate signaling proteins is established in pilot work . wilkes et al . ( 2000a ) and wilkes et al . ( 2000 b ) have found that 5 minute exposure provides the optimal period for detecting signaling protein activation for insulin in incubated muscles . lemieux et al ( 2000 ) have recently found that there are several intracellular glut 4 pools that are independently activated , thus it is conceivable that cpa and dpma may recruit glut 4 from one of these ‘ non - insulin sensitive ’ pools . optimal exposure times required for signaling protein activation by cpa and dpma are established . we do not assume that these are the same as for insulin . we establish that blocking p13 - kinase with ly29004 blocks downstream activation of akt by insulin , and by cpa and dpma . the impact of overexpressing a1 or a2a receptors on muscle glucose uptake electroporation , a method of non - viral gene transfer uses electric pulses ( electroporation ) to transfect prokaryotic and eukaryotic cells in vitro . mir et al . ( 1999 ) demonstrated conclusively that it is possible to transfer plasmid dna into skeletal muscle in vivo by using electroporation . the extent of the transfection is dependent on the voltage selected , pulse duration , number of pulses and their frequency . thus , it appears that electroporation increases gene transfer into muscle not only by muscle - fiber permeabilization but also by the direct effect on the dna molecule ( mir et al ., 1999 ). they have demonstrated i ) the very large increase in gene expression that could be attained , ii ) the long - term stability of the effect ( i . e . up to nine months ), iii ) the reduction in variability , iv ) its application to a variety of species ( mouse , rat , rabbit , monkey ), and v ) being able to regulate the degree of expression ( mir et al ., 1999 ). we are using the electroporation and cdna injection procedures of mir et al . ( 1999 ) to overexpress either the a1 or the a2a receptor alone or in combination in soleus muscle . the contralateral leg ( sham electroporation ) serves as control . we examine insulin , cpa and dpma - stimulated 3mgt , insulin signaling and the glut 4 responses in the isolated soleus muscles that contain the upregulated proteins . these experiments establish whether the increased availability of either a1 or a2a receptors , alone or in combination , further increase insulin , cpa and dpma - stimulated 3mgt , and glut - 4 translocation or activation , by means of procedures described in experiments outlined above . characterization of the impact of an adenosine receptor agonist in obese and type 2 diabetics , with emphasis on the ability of adenosine receptor agonist to increase glucose uptake groups of obese ( bmi & gt ; 30 ) ( n = 18 ), and type 2 diabetic ( n = 18 ) males , age 18 - 30 years undergo two ogtt &# 39 ; s , with and without adenosine receptor agonist ingestion one hour prior to ogtt . venous blood samples are taken at − 30 , 0 ( treatment given ), 60 ( ogtt administered ), 75 , 90 , 120 , 150 and 180 minutes and are analyzed for glucose , insulin , c peptide , glycerol , free fatty acids and lactate . area under the curve are calculated for the 2 hours of the ogtt . the obese subjects are class 1 ( bmi 30 - 34 ), abdominal obese ( waist circumference & gt ; 100 cm ) and the diabetics have the same anthropometry . the diabetics are volunteers who have been well controlled for a year , with glycosylated hemoglobin levels between 5 . 4 - 9 . 9 % for at least three months . they have similar levels of obesity , are not insulin - dependent , and are not on oral hypoglycaemic agents , but rather diet - controlled . their participation is medically approved and they are screened for hypertension and angina . effect of caffeinated coffee on the insulin and glucose responses to either a high or low glycemic index breakfast cereal in lean , resting males to date the majority of studies investigating caffeine and insulin resistance have compared pure caffeine with a standard 75 g oral dextrose load ( ogtt ) against a placebo treatment . the current study investigated whether impaired glucose management occurs with normal foods , namely following ingestion of coffee and either a high or low glycemic index ( gi ) breakfast cereal . young ( age = 24 ± 2 year ), non - obese ( bmi = 25 ± 1 kg / m 2 ), non - diabetic males ( n = 6 ) underwent four separate trials approximately one week apart , in a randomized order . the four treatments were : ( 1 ) caffeinated ( 5 mg / kg ) coffee with either a high glycemic index or ( 2 ) low glycemic index cereal or ( 3 ) decaffeinated coffee with either a high glycemic index or ( 4 ) low glycemic index cereal . cereal with 150 ml skim milk resulted in 75 g total carbohydrate for both the high ( gi = 81 ) and low ( gi = 41 ) glycemic index meals . this amount of carbohydrate was chosen to provide the same amount of carbohydrate ( 75 g ) as that used in our previous caffeine and ogtt studies in lean and obese males . venous blood samples were taken prior to ingestion of coffee ( t =− 60 minutes ) and cereal ( t = 0 minutes ) and at t = 15 , 30 , 45 , 60 , 90 and 120 minutes after cereal ingestion . there were no differences among the four trials in insulin , c - peptide or glucose prior cereal ingestion . insulin and c - peptide area under the curves were significantly increased with caffeinated coffee ( p & lt ; 0 . 05 ). specifically , after the high glycemic index meal , insulin area under the curve increased 93 % with caffeinated ( 3039 ± 413 uiu / ml / 2h ) vs decaffeinated ( 1574 ± 257 uiu / ml / 2h ) coffee , while after the low glycemic index meal , it was 69 % higher with caffeinated ( 1449 ± 194 uiu / ml / 2h ) vs decaffeinated ( 856 ± 148 uiu / ml / 2h ) coffee . similarly , c - peptide area under the curve increased 54 % with caffeinated ( 567 ± 79 ng / ml / 2h ) vs decaffeinated ( 369 ± 48 ng / ml / 2h ) coffee after the high glycemic index meal and was 39 % higher with caffeinated ( 258 ± 42 ng / ml / 2h ) vs decaffeinated ( 185 ± 12 ng / ml / 2h ) coffee after the low glycemic index meal . the increased insulin and c - peptide responses with caffeinated coffee occurred with significantly elevated blood glucose ( p & lt ; 0 . 05 ). specifically , after the high glycemic index meal , glucose area under the curves were 186 ± 46 and 14 ± 20 mm / 2h with caffeinated and decaffeinated coffee , respectively , while after the low glycemic index meal , glucose results were 88 ± 23 and 5 . 3 ± 14 mm / 2h with caffeinated and decaffeinated coffee , respectively . this study was the first to examine the effects of caffeine on blood glucose management using coffee and a more typical breakfast meal as opposed to pure caffeine and an ogtt . the results of the current study support our previous findings in that the ingestion of caffeinated coffee ( equivalent to 5 mg caffeine per kg body weight ) prior to a 75 g carbohydrate load ( breakfast cereal ) resulted in impaired glucose management in lean , healthy males . overall , insulin , c - peptide , and glucose responses were elevated and prolonged with caffeinated coffee and either a high or low glycemic index cereal . furthermore , the results suggest that the caffeine - induced impairment in blood glucose management was more pronounced after ingestion of the high glycemic index cereal , which represents a very common type of breakfast cereal consumed in the general population . effect of caffeine on blood glucose response to a high glycemic index cereal in young type 1 diabetics young type 1 diabetics ( 5 females and 1 male ) who had been diagnosed for an average of 8 . 3 ± 5 . 4 years volunteered to perform two trials in a randomized , double blind study design . subjects were given either placebo or caffeine - containing ( 5 mg / kg ) capsules and 30 minutes later they self - administered the appropriate amount of insulin for the ingestion of 60 g of carbohydrates in the form of a high glycemic cereal with 125 ml of 1 % milk . the amount of self - administered insulin and injection site were the same for both trials . venous blood glucose was measured prior to capsule ingestion , prior to insulin injection , and immediately following ingestion of the cereal meal ( t = 0 minutes ). blood glucose was then measured every 15 minutes for the next 2 . 5 hours . the 72 % difference in the glucose area under the curve for the caffeine and placebo trials ( 598 ± 7 . 4 and 347 ± 7 . 4 mm / 2 . 5 h , respectively ) were significantly different ( p & lt ; 0 . 01 ). the results from this study strongly suggest that caffeine ingestion caused a substantial impairment in glucose management which resulted in type 1 diabetics experiencing a high and prolonged elevation in blood glucose . these findings have important implications for type 1 diabetics who consume caffeine since individuals with type 1 diabetes lack the ability to produce endogenous insulin and thus must self - monitor their blood glucose levels and insulin requirements throughout the day . the effect of caffeine on glucose and insulin responses in obese individuals with type 2 diabetes obese ( bmi = 32 ± 1 kg / m 2 ) type 2 diabetic males ( n = 8 , age = 46 ± 2 year ) underwent two ogtts , with and without caffeine ( 5 mg / kg ) one hour prior to ingestion of 75 g of dextrose . subjects had an average glycosylated hemoglobin level of 7 . 8 ± 0 . 1 %, had no diabetes - related visual or renal complications , and were not taking insulin to control their diabetes . subjects were required to abstain from caffeine - containing food and beverages , alcohol , exercise and oral hypoglycemic medication for 48 hours prior to each trial . venous blood samples were taken prior to ingestion of caffeine or placebo ( time =− 60 minutes ) and the 75 g glucose load ( t = 0 minutes ) with subsequent samples taken at t = 15 , 30 , 60 , 90 , 120 , 150 and 180 minutes after glucose ingestion . based on our previous findings in obese males , the current protocol with obese type 2 diabetic subjects was designed to monitor blood glucose levels ( as well as other blood metabolites ) for an additional hour beyond the standard ogtt protocol we had previously used ( i . e . 3 hour instead of 2 hour post glucose ingestion ). average fasting blood glucose was 6 . 7 ± 0 . 3 mm and there were no differences between or within trials in blood glucose levels prior to ingestion of the oral glucose load . ingestion of caffeine resulted in significantly elevated ( p & lt ; 0 . 05 ) blood glucose for the last hour of the ogtt ( from 120 to 180 minutes following glucose ingestion ) when compared with placebo . furthermore , when subjects ingested caffeine , blood glucose remained significantly elevated ( p & lt ; 0 . 05 ) at 180 minutes following ingestion of the ogtt ( 8 . 4 ± 0 . 8 vs 7 . 4 ± 1 . 0 mm for caffeine and placebo , respectively ) compared with baseline values . thus , our study investigating the influence of caffeine followed by an ogtt in obese type 2 diabetics suggests that caffeine ingestion leads to elevated and prolonged blood glucose levels in these individuals . this caffeine - induced effect on blood glucose levels is comparable to our previous findings in both lean and obese non - diabetic subjects and provides further support for a negative impact of caffeine on blood glucose management . furthermore , we have now demonstrated that caffeine ingestion creates a situation ( i . e hyperglycemia ) in which there are greater demands on insulin secretion in those already experiencing insulin resistance , such as obese type 2 diabetics . overall , our results suggest that an individual with type 2 diabetes will spend a prolonged period of time in a hyperglycemic state following ingestion of caffeine and an oral glucose load . this negative impact of caffeine may have important implications since prolonged hyperglycemia is associated with a variety of long - term complications , such as microvascular , renal and visual complications . pharmaceutical compositions of the above compounds are used to treat patients that are obese and or have diabetes . vehicles for delivering the compounds of the present invention to target tissues throughout the human body include saline and d5w ( 5 % dextrose and water ). excipients used for the preparation or oral dosage forms of the compounds of the present invention include additives such as a buffer , solubilizer , suspending agent , emulsifying agent viscosity controlling agent , flavour , lactose filler , antioxidant , preservative or dye . there are preferred excipients for parenteral and other administration . these excipients include serum albumin , glutamic or aspartic acid , phospholipids and fatty acids . the preferred formulation is in liquid form stored in a vial or an intravenous bag . the compounds of the present invention may also be formulated in solid or semisolid form , for example pills , tablets , creams , ointments , powders , emulsions , gelatin capsules , capsules , suppositories , gels or membranes . acceptable routes of administration include intravenous , oral , topical , rectal , parenteral ( injectable ), local , inhalant and epidural administration . the compositions of the invention may also be conjugated to transport molecules or included in transport modalities such as vesicles and micelles to facilitate transport of the molecules . methods for the preparation of pharmaceutically acceptable compositions that can be administered to patients are known in the art . the compositions of the invention may also be conjugated to transport molecules , monoclonal antibodies or transport modalities such as vesicles and micelles that preferentially target recipient cells . pharmaceutical compositions including the compounds of the present invention can be administered to humans and animals . dosages to be administered depend on individual patient condition , indication of the drug , physical and chemical stability of the drug , toxicity , the desired effect and on the chosen route of administration . these pharmaceutical compositions are used to treat obesity and diabetes . although the invention has been described with preferred embodiments , it is to be understood that modifications may be resorted to as will be apparent to those skilled in the art . such modifications and variations are to be considered within the purview and scope of the present invention . all publications , patents , and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication , patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety . battram , d . s ., rowland , m ., marko , n ., graham , t . 1999 . cdn . j . appl . physiol . 24 : p . 425 bonen , a , m g clark , and e j henriksen . am j physiol 266 : e1 - e16 , 1994 . bonen , a ., l a megeney , s c mccarthy , j c mcdermott , and m h tan . biochem biophys res comm 187 : 685 - 691 , 1992 . brundin , t , r branstrom , and j wahren . am j physiol 271 : e496 - e504 , 1996 . budohoski , l , r a j challiss , b mcmanus , and e a newsholme . febs 167 : 1 - 4 , 1984 . carey , g b and k a sidmore . int j obesity 18 : 155 - 160 , 1994 . challiss , r a j , l budohoski , b mcmanus , and e a newsholme . biochem j 221 : 915 - 917 , 1984 . challiss , r a j , s j richards , and l budohoski . eur j pharmacol 226 : 121 - 128 , 1992 . cortright , r n and g l dohm . can j appl physiol 22 : 519 - 530 , 1997 . crist , g h , b xu , k f lanoue , and c h lang . faseb j 12 : 1301 - 1308 , 1998 . dixon , a k , a k gubitz , d j s sirinathsinghji , p j richardson and t c freeman . br j pharmacol 118 : 1461 - 1468 , 1996 . etgen jr , g j , c m wilson , j jensen , c w cushman , and j l ivy . am j physiol 271 : e294 - e301 , 1996 . graham , t e and k b adamo . can j appl physiol 24 : 393 - 415 , 1999 . graham , t . e ., sathasivam , p ., rowland , m ., marko , n ., greer , f ., battram , d . 2001 can . j . physiol . pharmacol . ( in press ). greer , f ., hudson , r . ross , r ., graham , t . 1998 . clinical and investigative medicine 83 ( suppl ) greer , f ., hudson , r ., ross , r ., graham , t . 2001 . diabetes ( in press ) han , x x , and a bonen . am j physiol . 274 : e700 - e707 , 1998 . han , d - h , p a hansen , l a nolte and j o holloszy . diabetes 47 : 1671 - 1675 , 1998 . hansen , p a , w wang , b a marshall , j o holloszy , and m mueckler . j biol chem 273 : 18173 - 79 , 1998 . laybutt , d r , d j chisholm and e w kraegen . am j physiol 273 : e1 - e9 , 1997 . lemieux , k , x x han , l dombrowski , a bonen , and a marette . diabetes 49 : 183 - 189 , 2000 . lund , s , g d holman , o scmitz , and o pedersen . pnas 92 : 5817 - 5821 , 1995 . meitzer , s , l leiter , d daneman , h gerstein , d lau , s ludwig , j - f yale , b zinman , and d lillie . can med assoc j 159 ( 8 suppl ) 51 - 58 , 1998 . mauriege , p , d prud &# 39 ; homme , s lemieux , a tremblay , and j p despres . am j physiol 269 : e341e - 350 , 1995 . mir , l , m f bureau , j gehl , r rangara , d rouy , j m caillaud , p delaere , d branellec , b schwartz , and d scherman . pnas 96 : 4262 - 4267 , 1999 . reynolds iv , t h , j t brozinick , m a rogers , and s w cushman . am j physiol 272 : e320 - e325 , 1997 . shaw , j e , p e zimmet , d mccarty , and m de courten . diabetes care 23 : b5 - b10 , 2000 . takasuga , s , t katada , m ui , and o hazeki . j biol chem 274 : 19545 - 50 , 1999 . tan , m - h and d r maclean . clin invest med 18 : 240 - 246 , 1995 . taylor , r , t b price , l d katz , r g shulman , and g i shulman . am j physiol 265 : e224 - e229 , 1993 . vergauwen , l , p hespel , and e a richter . j clin invest 93 : 974 - 981 , 1994 . webster , j m , l heseltine , and r taylor . biochim biophys acta 1316 : 109 - 113 , 1996 . wilkes , j j , and a bonen . am j physiol . in press , 2000 . wilkes , j j , r c bell , and a bonen faseb j 14 : a 91 , 2000 . wilkes , j j , s rodriguez , r c bell , and a bonen . faseb j 14 : a490 , 2000 . xu , b , d a berkich , g h crist , and k f lanoue . am j physiol 274 : e271 - e279 , 1998 . zhang , y and j n wells . j pharmacol exp therap 254 : 254 : 757 - 763 , 1990 .
a method for the prevention and treatment of diabetes and obesity by a system of health management promoting a caffeine reduced diet and the use of adenosine analogues and adenosine receptor agonists . methods for diet plans and labelling are disclosed . use of decaffeinated coffee is promoted .