A method and system for estimating fractional fat content of an object of interest. An energy emitter is used to direct an energy signal with an energy signal electric field strength toward the region of interest, wherein the region of interest has an object of interest, a reference, and a boundary between the object of interest and the reference. Next, a thermoacoustic or ultrasonic transducer is used to receive a thermoacoustic bipolar signal from the boundary, wherein the thermoacoustic bipolar signal is induced by the energy signal. Finally, a machine is used to accept data from the energy emitter and thermoacoustic or ultrasonic transducer, correlate the thermoacoustic bipolar signal to an electric field strength of the reference at the boundary to generate a corrected thermoacoustic bipolar signal at the boundary, and calculate a fat concentration of the object of interest as a function of the corrected thermoacoustic bipolar signal at the boundary.