We are in the so-called nutritional transition, in which obesity and its comorbidities have emerged as an important research topic, and the information on food composition is fundamental to promote nutritional safety. Fructose is the sweetest carbohydrate, and this sweetness, along with its low cost, is the key factor for its use in commercial drinks and sweets. The global average consumption of fructose per capita has increased from 56 g/day in 1986 to 65 g/day in 2007. Experimental models associate high fructose intake with the development of obesity and induced insulin resistance. In recent studies, diabetic patients have been reported to use fructose more frequently than glucose. Fructose acts differently in the hypothalamus and generates less satiety than glucose; thus, fructose has a high lipogenic potential. Replacing fructose with another isocaloric carbohydrate is associated with better glycemic control.