Most systematic review s and meta-analyses from controlled feeding trials have shown that fructose-containing sugars in isocaloric exchange for other carbohydrates do not show evidence of harm and , in the case of fructose , may even have advantages for glycaemic control , especially at small doses .
Nevertheless , trials in which fructose-containing sugars supplement diets with excess energy have shown adverse effects , effects that appear more attributable to the excess energy than the sugar .
There is no unequivocal evidence that fructose intake at moderate doses is directly related with adverse metabolic effects , although there is potentially cause for concern where fructose is provided at high doses or contributes excess energy to diets .
Concerns are growing regarding the role of dietary sugars in the development of obesity and cardiometabolic diseases , including diabetes .
High-fructose corn syrup ( HFCS ) and sucrose are the most important dietary sweeteners .
Both HFCS and sucrose have overlapping metabolic actions with adverse effects attributed to their fructose moiety .
Ecological studies have linked the rise in fructose availability with the increases in obesity and diabetes worldwide .
This link has been largely underpinned by animal models and select human trials of fructose overfeeding at high levels of exposure .
Acute fructose administration decreases the glycemic response to an oral glucose tolerance test in normal adults.
In animal models , a small ( catalytic ) dose of fructose administered with glucose decreases the glycemic response to the glucose load . Therefore , we examined the effect of fructose on glucose tolerance in 11 healthy human volunteers ( 5 men and 6 women ) . Each subject underwent an oral glucose tolerance test ( OGTT ) on 2 separate occasions , at least 1 week apart . Each OGTT consisted of 75 g glucose with or without 7.5 g fructose ( OGTT+F or OGTT-F ) , in r and om order .  Arterialized blood sample s were obtained from a heated dorsal h and vein twice before ingestion of the carbohydrate and every 15 min for 2 h afterward . The area under the curve ( AUC ) of the change in plasma glucose was 19 % less in OGTT+F vs. OGTT-F ( P : < 0.05 ) . Glucose tolerance was improved by fructose in 9 subjects and worsened in 2 . All 6 subjects with the largest glucose AUC during OGTT-F had a decreased response during OGTT+F ( 31 + /- 5 % decrease ) . The insulin AUC did not differ between the 2 studies . Of the 9 subjects with improved glucose tolerance during the OGTT+F , 5 had smaller insulin AUC during the OGTT+F than the OGTT-F. Plasma glucagon concentrations declined similarly during OGTT-F and OGTT+F. The blood lactate response was about 50 % greater during the OGTT+F ( P : < 0.05 ) . Neither nonesterified fatty acid nor triglyceride concentrations differed between the two OGTT . In conclusion , low dose fructose improves the glycemic response to an oral glucose load in normal adults without significantly enhancing the insulin or triglyceride response .  Fructose appears most effective in those normal individuals who have the poorest glucose tolerance
Most systematic review s and meta-analyses from controlled feeding trials have shown that fructose-containing sugars in isocaloric exchange for other carbohydrates do not show evidence of harm and , in the case of fructose , may even have advantages for glycaemic control , especially at small doses .
Nevertheless , trials in which fructose-containing sugars supplement diets with excess energy have shown adverse effects , effects that appear more attributable to the excess energy than the sugar .
There is no unequivocal evidence that fructose intake at moderate doses is directly related with adverse metabolic effects , although there is potentially cause for concern where fructose is provided at high doses or contributes excess energy to diets .
Concerns are growing regarding the role of dietary sugars in the development of obesity and cardiometabolic diseases , including diabetes .
High-fructose corn syrup ( HFCS ) and sucrose are the most important dietary sweeteners .
Both HFCS and sucrose have overlapping metabolic actions with adverse effects attributed to their fructose moiety .
Ecological studies have linked the rise in fructose availability with the increases in obesity and diabetes worldwide .
This link has been largely underpinned by animal models and select human trials of fructose overfeeding at high levels of exposure .