A heating attachment for improving uniformity of microwave heating of a food product in a food container. The heating attachment has a microwave shield of microwave-reflective material. An attachment member is configured for attaching the shield to a food container in an operative association in which the container is disposed in a heating space by the shield. In this association, the shield improves the uniformity of microwave heating of a food product within the container. The heating attachment sufficiently surrounds the container in the operative association to capture the container for promoting breakage of the heating attachment when the container is removed therefrom to inhibit or prevent reuse of the heating attachment.