The consumption of fructose has increased in the last 50 years due to the incorporation into the diet of high fructose corn syrup (HFCS), present in industrialized products, such as sugary drinks. The intake of fructose in high concentrations can be associated with the increase of obesity and metabolic disorders. Fructose, a natural sugar found in many fruits, is consumed in significant quantities in Western diets. In equal amounts, it is sweeter than glucose or sucrose and, therefore, is commonly used as a sweetener. Due to the increase of obesity among the young and general population and the negative effects that can have in the short and long term it is important to consider where the calories that are ingested daily come from. This review will describe the relationship between fructose consumption in high concentrations and the risk of developing obesity, insulin resistance, de novo lipogenesis, nonalcoholic fatty liver, inflammation and metabolic syndrome.

KEY WORDS: Fructose; Obesity; adipose tissue; Insulin resistance.