High consumption of fructose rather than glucose promotes a diet-induced obese phenotype in Drosophila melanogaster

article During the last 20 years, there has been a considerable scientific debate about the possible mechanisms of induc- tion of metabolic disorders by reducing monosaccharides such as glucose or fructose. In this study, we report the metabolic rearrangement in response to consumption of these monosaccharides at concentrations ranging from 0.25% to 20% in a Drosophila model. Flies raised on high-glucose diet displayed delay in pupation and increased developmental mortality compared with fructose consumers. Both monosaccharides at high concentrations pro- moted an obese-like phenotype indicated by increased fly body mass, levels of uric acid, and circulating and storedcarbohydratesandlipids;anddecreasedpercentage of waterinthe body.However, fliesraisedonfructose showed lower levels of circulating glucose and higher concentrations of stored carbohydrates, lipids, and uric acid. The preferential induction of obesity caused by fructose in Drosophila was associated with increased food consumption and reduced mRNA levels of DILP2 and DILP5 in the brain of adult flies. Our data show that glucose and fructose differently affect carbohydrate and lipid metabolism in Drosophila in part by modulation of insulin/