Fructose has lately become the subject of extensive research. The aim of this thesis was to get a general picture of fructose metabolism, its chemical characteristics, sources, effect of fructose on the sense of satiety and the consequences of its increased consumption. Fructose falls into a six-carbon sugar group, namely a hexose. Although it shares the same molecular formula as glucose, differences in their structural formula lead to significant differences in their chemical and physical properties and their metabolism. Fructose is primarily metabolised in the liver. The most important characteristic of fructose metabolism in the liver is that fructose-1phosphate bypasses the key step of glycolysis regulation, catalyzed by phosphofructokinase I. This ultimately leads to an increased concentration of precursors for de novo lipogenesis, hence the largest number of studies are directed toward the consequences of increased fructose consumption.