Non-alcoholic fatty liver disease (NAFLD) and Type 2 Diabetes affect approximately 24% and 8% of the global population respectively. The Western diet, high in both carbohydrates and lipids, is believed to have a role in the development of chronic metabolic disease. Dysfunctional hepatic mitochondrial metabolism is also known to be a central feature of disordered metabolism. The objective of this study was to compare the roles of dietary carbohydrates vs. lipids in inducing dysfunctional hepatic mitochondrial metabolism. Mice, C57BL/6NJ were kept on one of three diets: low-fat control (LF; 10% kcal fat), high-fat (HF; 60% kcal fat), and high-carbohydrate (HC; 25% kcal fat and 34.9% kcal fructose) for 10 weeks. Half of the mice were randomly selected to undergo a 16 hour fast prior to sacrifice, while the other half were not fasted. Within the fasted subset, the HC diet induced significantly elevated basal mitochondrial respiration (pmol Oxygen consumed/min) when compared with HF (HF, 70.1±5.8; HC,108.6±17.4; p<.05). Among fasted mice, the HC diet also appeared to induce significantly higher maximal respiration and ATP production when compared with HF. Expression of hepatic mitochondrial complex proteins were also higher in fasted HC mice than fasted HF mice. Overall, these results suggest that the high-carbohydrate diet enhanced mitochondrial activity when compared with the high-fat diet.