In vivo carbon-13 magnetic resonance spectroscopy is a quantitative technique for studying brain metabolism. Here, we demonstrate the use of 1H MRS to indirectly observe the metabolism of 13C labelled glucose, simultaneously in two brain regions in a single healthy volunteer. This was done using only standard proton (1H) MRS sequences and hardware. Our results demonstrate an accumulation of 13C label in glutamate and glutamine that is distinctly observable due to the pronounced effect of heteronuclear scalar coupling. This technique provides insight into neuronal metabolic rates and may provide complimentary information to 18F-FDG PET in the study of neurodegenerative disorders.