Table 2.

Comparison of glucose and fructose metabolism [2,47,48].

Feature	Monosaccharide Sugars
A Type of Monosaccharide	Glucose	Fructose
glycemic index (GI)	100	23
the main place of deposition of adipose tissue after consuming excess	subcutaneous tissue	visceral adipose tissue
place of metabolism	body cells	-small doses (first order): intestines -higher doses: liver and circulatory system
enzymes involved in metabolism	-glucokinase -phosphofructokinase	-fructokinase
regulation of metabolism	-dependent on phosphofructokinase	-does not depend on phosphofructokinase; -the accumulation of by-products leads to unlimited lipogenesis
serum concentration	-physiologically at a constant level -increases after a meal	-increases with glucose level
insulin dependence	excess causes insulin secretion	lack of phosphofructokinase involvement results in lack of insulin response
impact on appetite	-lowering the level of ghrelin -increasing glucagon-like peptide-1 (GLP-1) -increasing the level of glucose and insulin in the blood	-lowering the level of ghrelin -increasing GLP-1
the effect of metabolism on the body	glucose metabolites prevent excessive phosphorylation	rapid phosphorylation of fructose by the enzymes: -ATP depletion in vascular cells -ATP depletion in the liver -ATP depletion in proximal tubular cells what causes: -transient cessation of protein synthesis production of inflammatory proteins -endothelial dysfunction -oxidative stress