Carbohydrates are the most abundant macronutrient in the diet, their quality is paramount to good metabolic health. The glycaemic index (GI) measures carbohydrate quality based on postprandial blood glucose levels, with lower GI foods associated with better metabolic health. This study compared free sugars with a range of GIs from glucose (highest), sucrose (middle) and isomaltulose (lowest). C57BL/6 female mice were fed one of three sugar-based isocaloric diets or an AIN93-G control. Pups continued on their mother’s diet until 30-weeks to determine the effects of in-utero and lifelong exposure. Body composition was determined by EchoMRI, energy expenditure and respiratory quotient measured in Promethion metabolic cages and oral glucose tolerance tests (OGTT) were performed. Preliminary results show female mice exposed to high-sugar diets were heavier, longer and fatter by 30-weeks compared to controls. In male mice, glucose-fed pups were heavier, and all sugar-fed pups were fatter and longer compared to controls. Female sugar pups secreted more insulin in response to glucose, however, insulin peak response was delayed in mice fed isomaltulose. Overall, sugar-based diets increased food intake compared to starch-based AIN93-G at 12- and 24-weeks of age. Interestingly, at 24-weeks food intake was reduced compared to 12-weeks in sugar-fed mice. These results may be due to increased presence of liver fibrosis observed in 32% of glucose-, 38% of sucrose- and 24% of isomaltulose-fed mice and corroborated with histology. Preliminary results show female mice are more heavily affected at 30-weeks across all sugar diets with a higher body weight, percent fat, insulin response to an OGTT, increased food uptake and liver fibrosis. Male mice show less differences in weight but sugar still negatively effects body composition, food intake and liver fibrosis. These findings show that free sugars, regardless of their GI can induce changes in body composition and risk of metabolic disease.