Use of a susceptor (a metallized film attached to paperboard) in microwave heating can emulate conventional heating with benefits such as crisping food. This study develops a mechanistic understanding of this food-susceptor heating process. A coupled electromagnetic-thermal model was developed" and validated for heating frozen food (a pie) in a package on a rotating turntable. Experimental measurements show that the susceptor has a moderately high dielectric constant but it also has a high dielectric loss, making it strongly microwave absorbing. Computed electric field, temperature, and energy absorption provided a comprehensive understanding. Presence of the susceptor increases the average conductive heat flux at the food-susceptor interface from similar to 500 W/m(2) to similar to 2000 W/m(2). By increasing the heat flux at the interface, a susceptor causes the food to absorb nearly three times as much energy initially, with the rate decreasing as the material thaws. The heating effectiveness of a susceptor increases when combined with rotation. (C) 2016 Elsevier Ltd. All rights reserved.