This paper describes a method for the measurement of fuel oxidation in Drosophila melanogaster in which trace amounts of specific radiolabeled metabolic substrates are fed to flies. The exhaled radiolabeled CO2 that is a produced from fuel oxidation is collected and measured.
Bland, M. L. Measurement of Carbon Dioxide Production from Radiolabeled Substrates in Drosophila melanogaster. J. Vis. Exp. (112), e54045, doi:10.3791/54045 (2016).